United States Department of Agriculture

Agroforestry: 

Enhancing Resiliency in 

U.S. Agricultural Landscapes 

Under Changing Conditions

Forest Service Gen. Tech. Report WO-96 November 2017
Michele M. Schoeneberger is Research Program Lead and soil scientist (retired), U.S. Department of Agriculture, Forest Service, USDA National Agroforestry Center; Gary Bentrup is a research landscape planner, U.S. 

Department of Agriculture, Forest Service, USDA National Agroforestry Center; Toral Patel-Weynand is the 

Director of Sustainable Forest Management Research, U.S. Department of Agriculture, Forest Service, Research 

and Development.

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https://doi.org/10.2737/WO-GTR-96
United States Department of Agriculture

Agroforestry: 

Enhancing Resiliency in 

U.S. Agricultural Landscapes 

Under Changing Conditions

Michele M. Schoeneberger, Gary Bentrup, 

and Toral Patel-Weynand

Editors

U.S. Department of Agriculture

Forest Service

Washington, DC

Forest Service Gen. Tech. Report WO-96 November 2017
ii Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions
Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions iii

Contents

Executive Summary ................................................................................................................................................ v

Overview and Purpose ...................................................................................................................................... v

Key Messages................................................................................................................................................... vi

Literature Cited................................................................................................................................................. xi

Chapter 1. Introduction.......................................................................................................................................... 1

Literature Cited.................................................................................................................................................. 5

Chapter 2. Reducing Threats and Enhancing Resiliency.................................................................................... 7

Adaptive Capacity of U.S. Agriculture.............................................................................................................. 7

Commodity Production ..................................................................................................................................... 8

Crop Diversity ................................................................................................................................................. 11

Soil Resources................................................................................................................................................. 13

Water Resources.............................................................................................................................................. 15

Air Quality....................................................................................................................................................... 19

Biodiversity ..................................................................................................................................................... 21

Adaptable Plantings......................................................................................................................................... 25

Literature Cited................................................................................................................................................ 28

Chapter 3. Greenhouse Gas Mitigation and Accounting................................................................................... 43

Potential Greenhouse Gas Mitigation Roles of Agroforestry.......................................................................... 44

Carbon Accounting at the Entity Level ........................................................................................................... 51

Carbon Accounting at the Regional and National Levels................................................................................ 53

Advancing Greenhouse Gas Performance and Accounting in Agroforestry Systems..................................... 55

Literature Cited................................................................................................................................................ 58

Chapter 4. Valuation of Agroforestry Services.................................................................................................... 63

Valuation of Financial Returns to the Landowner........................................................................................... 64

Valuation of Ecosystem Services and Externalities From Agroforestry ......................................................... 65

Risk and Uncertainty....................................................................................................................................... 68

Summary and Conclusions.............................................................................................................................. 69

Literature Cited................................................................................................................................................ 69

Chapter 5. Human Dimensions of Agroforestry Systems.................................................................................. 73

Agroforestry Adoption Constraints and Opportunities................................................................................... 73

Indigenous Systems as Models for Modern Resiliency .................................................................................. 78

Conclusions..................................................................................................................................................... 84

Literature Cited................................................................................................................................................ 84

Chapter 6. Agroforestry Resources...................................................................................................................... 91

Decision-Support Tools................................................................................................................................... 91

Conservation Programs ................................................................................................................................... 94

Challenges and Opportunities ......................................................................................................................... 95

Literature Cited.............................................................................................................................................. 100
iv Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions

Chapter 7. Expanding the North American Perspective—Canada ................................................................ 101

Impacts of Climate Change on Canadian Agriculture................................................................................... 101

Agroforestry Across Canada ......................................................................................................................... 102

Overview of Existing Policies and Programs................................................................................................ 106

Needs for Agroforestry in Canada................................................................................................................. 108

Literature Cited.............................................................................................................................................. 111

Chapter 8. Expanding the North American Perspective—Mexico ................................................................. 113

Impacts of Climatic Variability on Mexican Agriculture .............................................................................. 113

Overview of Agroforestry in Mexico ............................................................................................................ 114

Overview of Existing Policies....................................................................................................................... 120

Constraints to Adoption and Implementation of Agroforestry Systems in Mexico ...................................... 124

Needs and Emerging Opportunities for Agroforestry in Mexico.................................................................. 125

Literature Cited.............................................................................................................................................. 126

Chapter 9. Challenges and Opportunities ........................................................................................................ 131

Information Challenges................................................................................................................................. 132

Emerging Opportunities: Capitalizing on Agroforestry’s Versatility ............................................................ 134

Conclusions................................................................................................................................................... 136

Literature Cited.............................................................................................................................................. 136

Glossary ............................................................................................................................................................... 139

Appendix A. Regional Summaries..................................................................................................................... 143

Alaska............................................................................................................................................................ 143

Hawaii and the U.S.-Affiliated Pacific Islands .............................................................................................. 147

Northwest ...................................................................................................................................................... 154

Southwest ...................................................................................................................................................... 160

Great Plains................................................................................................................................................... 169

Midwest ......................................................................................................................................................... 177

Northeast ....................................................................................................................................................... 184

Southeast and Caribbean ............................................................................................................................... 189

Appendix B. Risk-Based Framework and Assessments of Agroforestry as a Climate Change 

Adaptation and Mitigation Strategy .............................................................................................................. 203

Risk-Based Framework for Evaluating Adaptation and Mitigation Strategies.............................................. 203

Evaluation of Agroforestry for Reducing Soil Erosion................................................................................. 205

Evaluation of Agroforestry for Protecting Coldwater Fish Habitat............................................................... 207

Evaluation of Agroforestry for Carbon Sequestration................................................................................... 210

Suitable Tree Species Under a Changing Climate......................................................................................... 212
Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions v

Executive Summary

Toral Patel-Weynand, Gary Bentrup, and Michele Schoeneberger

Toral Patel-Weynand is the Director of Sustainable Forest Management Research, U.S. Department of 

Agriculture (USDA), Forest Service, Research and Development; Gary Bentrup is a research landscape 

planner, USDA Forest Service, USDA National Agroforestry Center; Michele Schoeneberger is research 

program lead and soil scientist (retired), USDA Forest Service, USDA National Agroforestry Center.

Overview and Purpose

Agroforestry, the intentional integration of trees and shrubs into 

crop and animal production systems, is being deployed to enhance productivity, profitability, and environmental stewardship 

of agricultural operations and lands across the United States.

This assessment provides a science-based synthesis on the use 

of agroforestry for mitigation and adaptation services in the face 

of climatic variability and change. It provides technical input 

to land-use sector issues in the National Climate Assessment 

(NCA) and serves as a framework for including agroforestry 

systems in agricultural strategies to improve productivity and 

food security and to build resilience in these landscapes. It also 

provides follow-up to the technical input report by Walthall et 

al. (2012) that established the need for innovative strategies to 

address significant climatic variability challenges faced by U.S. 

agriculture.

The five widely recognized categories of agroforestry in the 

United States are (1) silvopasture, (2) alley cropping, (3) forest 

farming (or multistory cropping), (4) windbreaks, and (5) riparian 

forest buffers. Such practices can help to mitigate greenhouse 

gas (GHG) emissions and increase the resiliency of agricultural 

lands to address impacts from climatic variability. They can also 

enhance agricultural production; protect soil, air, and water quality; 

provide wildlife habitat; and allow for diversified income.

This report provides a science-based assessment of adaptation 

and mitigation mechanisms that agroforestry can confer, all 

of which are important for food security. It reviews social, 

cultural, and economic aspects of agroforestry and the capacity 

of agroforestry systems to provide multipurpose solutions. In 

addition, it presents a comprehensive North American perspective on the strengths and limitations of agroforestry through 

U.S. regional overviews as well as overviews for Canada and 

Mexico.

A range of national stakeholder perspectives was included, with 

participation from Federal and State governments, tribal lands, 

nongovernmental organizations, academic institutions, and 

professional organizations. Their input throughout the process 

has ensured up-to-date and relevant subject matter information 

for decisionmakers, practitioners, and researchers.

Agroforestry is the intentional blending of trees and shrubs into crop and livestock systems to increase production and environmental 

services we derive on our Nation’s farms and ranches. 

Photo credits (from left to right): Gary Wells, USDA Natural Resources Conservation Service. Jim Robinson, USDA Natural Resources Conversation Service.
vi Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions

Climatic variability poses significant challenges for farmers and ranchers. This report assesses how agroforestry practices can add 

structural and functional diversity to boost resiliency of U.S. agriculture in face of these challenges. 

Photo credits (from left to right): Lynn Betts, USDA Natural Resources Conservation Service. Beverly Moseley, USDA Natural Resources Conservation Service.

This report provides an in-depth assessment of agroforestry 

as one strategy for strengthening the adaptive capacity of U.S. 

farms and ranches. The introduction provides an overview and 

addresses how agroforestry can provide adaptive and mitigative 

solutions for agriculture. The remaining chapters present in 

greater detail the biophysical dimensions, human dimensions, 

and regional considerations regarding the utility of agroforestry 

for addressing changing conditions. The chapters are—

• Reducing Threats and Enhancing Resiliency.

• Greenhouse Gas Mitigation and Accounting.

• Valuation of Agroforestry Services.

• Human Dimensions of Agroforestry Systems.

• Agroforestry Resources.

• Expanding the North American Perspective—Canada.

• Expanding the North American Perspective—Mexico.

• Challenges and Opportunities.

Key Messages

Ecosystem Services and Food Security Benefits 

of Agroforestry

Intensive (e.g., seed genetics) and extensive (e.g., landscape 

diversification) actions are being proposed to address extreme 

weather and climatic variability predicted for U.S. agriculture. 

Agroforestry is a unique extensive action involving the integration of woody plants with crop and livestock components. This 

approach has been documented to deliver a host of ecosystem 

goods and services, from food production to protection and 

enhancement of natural resources important to agriculture. 

Research suggests that agroforestry helps sustain these 

ecosystem services by increasing resilience to risks, shocks, 

and long-term effects from climatic variability and change. 

Agroforestry accomplishes these production and environmental 

benefits by—

• Modifying microclimate in ways that can improve crop 

yields from 6 to 56 percent depending on crop type.

• Reducing soil erosion from water and wind, and improving 

soil physical condition and fertility, thereby protecting 

future soil productivity.

• Modifying microclimate in ways that protect livestock 

productivity and well-being.

• Protecting streambanks and infrastructure, moderating water 

pollution, and ameliorating high stream temperatures, thus 

protecting water quality and aquatic ecosystems.

• Creating habitat refugia and connectivity across highly 

fragmented agricultural landscapes, protecting biodiversity, 

including pollinators and beneficial insects.

• Generating innovative food-producing systems that diversify 

farm portfolios and increase economic stability for the 

landowner.
Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions vii

Agroforestry practices are multifunctional strategies that can 

work at multiple scales to provide several benefits. A single 

practice can be designed to help diversify farm income, 

enhance production, and provide wildlife resources, while also 

sequestering carbon and improving water, air, and soil quality. 

Photo credits (from top to bottom): Ben Fertig, Integration 

and Application Network, University of Maryland Center for 

Environmental Science (ian.umces.edu/imagelibrary/). USDA 

National Agroforestry Center.

Agroforestry as a Mechanism for Greenhouse 

Gas Mitigation

Agroforestry can be an important component of a comprehensive GHG mitigation strategy by sequestering carbon (C) in 

biomass and soils and reducing GHG emissions on agricultural 

lands, especially through avoided emissions via energy savings 

and fuel reductions. The lack of activity-specific data limits 

inclusion of agroforestry in national accounting and inventory 

efforts in the United States. The amounts and duration of C sequestration and reduction in GHG emissions are influenced by 

design specifics, local site conditions, and management activities, 

making agroforestry a complex but flexible mitigation option. 

An advantage is that C sequestration and GHG mitigation are 

but two of many benefits agroforestry can provide to agricultural operations and lands. Effective inclusion of agroforestry 

in national-level estimations for GHG emission reductions will 

require—

• Better understanding of soil C and other GHG dynamics 

across agroforestry systems and settings.

• Refined tools and methodologies for measuring the longterm potential of agroforestry systems to mitigate GHG 

emissions.

• A national inventory that tracks land under agroforestry, to 

feed into U.S. GHG inventory assessments.

• A common GHG assessment framework for national 

coordination of agroforestry GHG efforts.

Economic and Sociocultural Considerations

Knowledge of the financial benefits of agroforestry to landowners, 

and an understanding of ecosystem service benefits to society, 

will be critical to agroforestry outreach efforts. The few economic 

studies available suggest that agroforestry offers financial benefits 

for producers on marginal lands. Due to the long timeframe 

for agroforestry plantings to mature and provide the full suite 

of benefits, agroforestry may be less competitive with annual 

cropping systems on highly productive lands. However, when 

ecosystem services are factored in, agroforestry can be competitive on prime agricultural lands as well.

Voluntary, conservation-based programs at the Federal, State, 

and local levels provide financial incentives for landowners to 

implement agroforestry practices. Additional economic benefits 

will likely be derived from the ability of agroforestry practices 

to mitigate and adapt to climatic variability, particularly in 

response to extreme weather events.

Additional considerations influencing agroforestry adoption in 

the United States include a long management timeframe, complex systems, a lack of information, and the need for specialized 

equipment. Approaches for increasing agroforestry adoption 

include increased education and technical support as well as innovative partnerships, such as equipment-sharing cooperatives. 

In response to surveys, most farmers indicated they would like 

to do more to protect their operations and lands from climatic 

variability. Such farmers may be open to new approaches, such 

as partnering with others, to create more resilient agricultural 

landscapes that include agroforestry practices.
viii Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions

Agricultural producers are a diverse group, and agroforestry 

practices can be tailored to address individual farmer and 

rancher objectives and situations.

Photo credits (from top to bottom): USDA National Agroforestry 

Center. Ron Nichols, USDA Natural Resources Conservation 

Service. Bob Nichols, USDA Office of Communications.

Indigenous and tribal agroforestry systems of the United States 

and U.S.-affiliated islands provide time-tested models that 

inform modern agroecosystem management. These systems 

employ agroforestry to maintain and enhance food, fiber, and 

medicinal resources for local livelihoods and economies. They 

are often locally adaptive and reflective of tribal traditions. 

Traditional ecological knowledge has diminished due to the 

declining transfer of knowledge from older to younger generations. This loss is a result of cultural and value changes and an 

increasing focus on other employment options. Maintenance 

and renewal of indigenous and tribal agroforestry practices will 

need to be supported by increased awareness and transfer of 

traditional ecological knowledge.

U.S. Regional Summaries

An overview of regional perspectives on the status and potential 

future role of agroforestry in each of the NCA regions follows.

Alaska

• Although only 0.2 percent of Alaska is actively farmed, 

agriculture plays an important local and regional role.

• Alaska has warmed twice as fast as the rest of the Nation 

and changes are so rapid that they are difficult to anticipate, 

even with the best models. Future increases in temperatures 

may result in conditions more favorable to agriculture.

• Riparian forest buffer use is increasing in southeast Alaska 

and may help offset some climatic variability impacts on 

aquatic health and fisheries.

• Forest farming opportunities exist for high-value and culturally 

significant understory crops, including mushrooms, berries, 

medicinal plants, and traditional native foods.

• Windbreak establishment may be helpful to the vegetable 

production now becoming possible under warming conditions, 

thus supporting new avenues for addressing food insecurity 

issues affecting Alaska Native peoples.

Hawaii and the U.S.-Affiliated Pacific Islands

• Although arable land is limited on the islands, farming is 

vital to local economies and food security, particularly in 

areas where people rely on subsistence agriculture.

• Many climate-related stressors, including shifting rainfall 

patterns, changing storm and drought intensities, decreasing 

coastal stability, and salinization of groundwater, threaten 

the Pacific Islands.
Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions ix

• Agroforestry has been used in the Pacific Islands for centuries 

to produce numerous products for subsistence or sale (fruits, 

tubers, spices, medicines, wood, and fiber). These systems

reduce rainfall intensity and erosion from tropical storms 

and provide efficient use of land and water resources.

• Seaside plains are important areas for traditional agriculture, 

and coastal windbreaks can help dissipate wind energy and 

storm surges, thus increasing coastal stability.

Northwest

• Nearly one-fourth of the region’s land area is agricultural, 

providing 52 percent of the Nation’s potato crop, 17 percent 

of the Nation’s wheat, 11 percent of the Nation’s milk, and a 

diversity of fruit and nut crops.

• Heat stress, decreased chilling hours, increased drought, and 

reduced snowmelt are some of the challenges that farmers 

and ranchers in the Northwest face.

• The region’s tribal communities have historically practiced 

agroforestry, and some of these practices continue today. 

Silvopasture, windbreaks, and alley cropping may offer 

the most potential to modify microclimates in support of 

livestock and crop production.

• Riparian forest buffers are used in agricultural areas to lower 

stream temperatures to protect salmon and other cold-water 

species. A warming climate and reduced snowmelt will 

likely increase the need for riparian forest buffers.

Southwest

• More than one-half of the Nation’s high-value specialty 

crops come from the southwest region, which includes 

California. These crops are predominantly irrigation-dependent and vulnerable to water availability and temperature 

extremes. Extensive forested rangelands generate revenue 

through livestock and dairy production.

• Predicted changes in climate pose daunting challenges for an 

already parched region that is expected to get hotter and, in 

its southern half, significantly drier.

• Many specialty crops in the region require insect pollination, 

and agroforestry practices can create more diversified and 

resilient foraging and nesting habitat.

• Opportunities exist to manage forested rangelands as 

silvopasture systems that reduce fuel loads and severity of 

forest fires while enhancing forage and livestock production. 

Improved irrigation technologies may provide a means for 

increasing nut production from key agroforestry trees (e.g., 

pinyon pine, pecan) valued and grown in this region.

Great Plains

• More than 80 percent of the land area in the Great Plains is 

dedicated to cropland, pasture, and rangeland, with the total 

market value split about equally between crop and livestock 

production.

• Known for its historic weather extremes, the Great Plains 

region expects hotter temperatures with higher likelihood 

of heavy rain and snow events in addition to more intense 

droughts.

• Windbreaks have long played a role in combatting impacts 

from adverse climatic variability in the region, beginning 

with the 1930s Dust Bowl, and remain a logical choice for 

building greater resiliency in Great Plains agriculture and 

livestock production.

• Awareness of water quality and streambank stability issues 

in the region is increasing the use of riparian forest buffers 

and will likely continue as these issues intensify.

During the 1930s Dust Bowl, windbreaks were planted in the 

Great Plains to control soil erosion and protect crops, and 

they remain a logical choice for building greater resiliency in 

agriculture and livestock production.

Photo credits (from top to bottom): USDA Natural Resources 

Conservation Service. USDA Forest Service.
x Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions

Midwest

• More than two-thirds of the land in the Midwest is in 

agricultural use, with corn and soybean constituting 85 

percent of crop receipts.

• Increased heat stress, alternating flooding and drought 

cycles, and higher populations of harmful insects are major 

climatic challenges faced by producers in the region.

• Riparian forest buffers are used to reduce water-quality 

problems, and this need is expected to grow as extreme 

rainfall events increase.

• Expanding the use of windbreaks and alley cropping could 

buffer the effects of warmer temperatures on crops and 

livestock and help boost populations of beneficial insects.

Northeast

• About 21 percent of the region is in agricultural use, with 

the most prevalent commodities being dairy and poultry 

production and perennial fruits.

• Increasing heat waves, heat stress, extreme precipitation 

events, and flooding pose challenges for growing traditional 

crops and may lead to decreases in milk production. Warmer 

and wetter winters may impact survival and production in 

fruit- and nut-bearing plants.

• Riparian forest buffers have been used extensively in the 

Chesapeake Bay watershed and other areas to address water 

quality issues. Buffers will play an increasingly important 

role in mitigating the impacts of extreme precipitation 

events and flooding.

• Well-managed silvopasture systems could reduce heat stress 

on livestock while maintaining forest health. Forest farming 

may reduce the conversion of forest cover to other cover 

types less resilient to the effects of climatic variability and 

environmental change.

Southeast and Caribbean

• The Southeast is a diverse agricultural region, producing the 

majority of U.S. broiler chickens and peanuts (66 and 62 

percent, respectively) and one-third of cotton and tomatoes 

(37 and 33 percent). The Caribbean islands have limited 

arable land and depend on imported food.

• Extreme heat events, decreases in fresh water availability, 

and sea-level rise are some of the challenges faced by the 

region’s farmers and ranchers.

• Silvopasture, alley cropping, and forest farming are the 

most commonly used agroforestry practices, providing high 

potential for microclimate modification and efficient water 

resource use.

• In the Caribbean, the use of forest farming and other 

agroforestry practices to produce fruits, vegetables, and nuts 

on steep slopes can increase food security and reduce soil 

erosion.

Perspectives From Canada and Mexico

The challenges and opportunities for agroforestry to address 

climate-related impacts are similar in Canada and Mexico to 

those in the United States. A review of approaches taken in 

each country provides new insights for each and can help to 

identify additional opportunities for collaboration and partnerships.

Canadian agroforestry systems are similar to those found in 

the United States, with windbreaks and shelterbelts being 

the most widespread. Greater attention is being given to the 

use of agroforestry to address and mitigate environmental 

impacts of modern agriculture, including GHG emissions. 

Through the Agricultural Greenhouse Gases Program, the 

Canadian government is documenting the C sequestration 

potential of agroforestry across provinces, which may feed into 

future inventory reports. Conservation programs such as the 

community-developed, farmer-delivered Alternative Land Use 

Services provide important financial support for agroforestry 

adoption. To maximize efforts between Canada and the 

United States, a memorandum of understanding was signed 

in 2012 between the Agroforestry Development Centre of the 

Department of Agriculture and Agri-Food Canada and the 

National Agroforestry Center of the Forest Service, an agency 

of the U.S. Department of Agriculture (USDA). It called for 

collaborative activities on temperate agroforestry systems, with 

an emphasis on climatic variability and change.

In Mexico, many agroforestry systems are derived from traditional land-use systems developed by indigenous people over 

long periods of time and are well adapted to local conditions. 

These systems play an important role in food security by integrating a diversity of edible species, notably fruit trees, with 

perennial food crops and by providing fuelwood for cooking. 

Despite their value, Mexican agroforestry systems are suffering 

production declines due to disease, changes in climate, and 

land abandonment. Policies and incentive programs do not 

often include agroforestry because they are outside the mission 

of government agencies responsible for agricultural- or forestry-related programs. Agroforestry practitioners and advocates, 

however, are placing greater attention on agroforestry in 

promoting sustainable land use. Focusing on production of 

ecosystem goods and services provides options for addressing 

climatic variability and change.
Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions xi

Addressing the Challenges

The potential for agroforestry to provide mitigation and 

adaptation services in the face of climatic variability and 

change is documented by research. In addition, agroforestry 

plays a prominent role in the history of U.S. efforts to combat 

climate-related impacts to agriculture. In 1935, the Prairie 

States Forestry Program began planting more than 200 million 

tree seedlings as shelterbelts, to reclaim land ravaged by the 

Dust Bowl. Today the range of climate-related impacts to U.S. 

agriculture is greater, and so is the potential for agroforestry to 

address them. Agroforestry represents a promising management 

option, but critical challenges still exist for successful promotion, adoption, and long-term maintenance. The obstacles to 

adoption (e.g., lack of information, awareness, and technical 

and policy support) are recognized and will need to be addressed at appropriate scales.

Although the implementation of agroforestry systems can alleviate climate-related stressors to agriculture, they too may be 

vulnerable to climate-related impacts. The long-term benefits of 

agroforestry systems may be affected by stresses resulting from 

future climatic conditions. Future success may require development and introduction of new species and cultivars better 

adapted to current and future climatic conditions. Time and 

resources will need to be invested in improved seed sourcing, 

field evaluation trials, and enhanced predictive capability for 

modeling shifts in growing zones.

Although the practice of agroforestry involves considerable 

uncertainty, scientific principles and decision-support tools are 

available for taking action now. Technical assistance offered 

through Federal and State conservation programs provides 

planning and design processes for implementation. Transfer 

of technical knowledge can promote an adaptive management 

approach to addressing uncertainty and modifying management 

options. Adaptive management can reduce the risks of climatic 

variability in agriculture and forestry by improving planning, 

preventing maladaptation, and informing investment and 

management of resources (Peterson et al. 2014, Vose et al. 

2016, Walthall et al. 2012). By tracking the successes and 

failures of different adaptation actions, including agroforestry, 

landowners, practitioners, researchers, and institutions can 

produce more robust adaptation strategies over time.

U.S. and global communities will continue to experience challenges from climatic variability and change, and the potential 

effects on agricultural production pose a serious threat to 

food security around the world. Improving adaptive capacity 

in agricultural systems, while meeting food-security needs 

and enhancing C sequestration, is challenging. Agroforestry 

is a multipurpose option for farmers and ranchers to address 

adaptation, food security, and GHG mitigation concerns and 

to build the resilient agricultural landscapes needed under 

changing conditions.

Literature Cited

Peterson, D.L.; Vose, J.M.; Patel-Weynand, T., eds. 2014. 

Climate change and United States forests. Advances in Global 

Change Research. Vol. 57. Dordrecht, Netherlands: Springer. 

261 p.

Vose, J.M.; Clark, J.S.; Luce, C.; Patel-Weynand, T. eds. 2016. 

Effects of drought on forests and rangelands in the United 

States: a comprehensive science synthesis. Gen. Tech. Rep. 

WO-93b. Washington, DC: U.S. Department of Agriculture, 

Forest Service, Washington Office. 289 p.

Walthall, C.J.; Hatfield, J.; Backlund, P. [et al.]. 2012. Climate 

change and agriculture in the United States: effects and adaptation. Tech. Bull. 1935. Washington, DC: U.S. Department of 

Agriculture. 186 p.
xii Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions
Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions 1

Chapter 1

Introduction

Gary Bentrup, Michele Schoeneberger, Toral Patel-Weynand, Shibu Jose, Tara Haan Karel

Gary Bentrup is a research landscape planner, U.S. Department of Agriculture (USDA), Forest Service, 

USDA National Agroforestry Center; Michele Schoeneberger is research program lead and soil scientist 

(retired), USDA Forest Service, USDA National Agroforestry Center; Toral Patel-Weynand is the director of 

Sustainable Forest Management Research, USDA Forest Service, Research and Development; Shibu Jose

is the director of the School of Natural Resources, University of Missouri; Tara Haan Karel is an Oak Ridge 

Institute for Science and Education fellow, USDA Forest Service, State and Private Forestry.

Enhancing food security and preserving vital ecosystem services 

from agricultural lands are critical issues for the United States 

and have become increasingly important globally. Addressing 

these issues requires that forestry and agricultural systems 

become even more productive while ensuring that the other environmental services provided by these landscapes are available 

to future generations. To achieve higher levels of productivity 

and ensure long-term sustainability, these landscapes and production systems will need to use inputs more efficiently; have 

less variability and greater stability in outputs; and be more 

resilient to risks, shocks, and long-term climatic variability 

(Tilman et al. 2011). To achieve these goals will require a major 

shift in the way land, water, soil nutrients, and genetic resources 

are managed. In general terms, agroecological principles and 

practices that capitalize on greater multifunctionality also build 

in greater resiliency within the agricultural operations and 

landscapes in which they are applied (Beddington et al. 2012, 

Tomich et al. 2011).

As a multifunctional management strategy, agroforestry 

provides an intentional blending of forestry and agricultural 

practices that can address food security and stability in managing for other ecological and environmental services provided 

by these landscapes. As an agricultural management option, 

agroforestry is unique in that it is tree based, adding strategic 

diversity at various scales in ways that can reduce threats and 

build resiliency under changing conditions. Agroforestry, as defined within the United States, is “intensive land-use management that optimizes the benefits (physical, biological, ecological, economic, and social) from biophysical interactions created 

when trees and/or shrubs are deliberately combined with crops 

and/or livestock” (Gold and Garrett 2009). Better recognized 

within tropical agricultural strategies (Verchot et al. 2007), 

agroforestry is now emerging as a viable resiliency strategy 

for the United States and other temperate regions, especially 

in regards to helping producers deal with the impacts from the 

increasing erratic and extreme weather events (Delgado et al. 

2011, Jose et al. 2012, Schoeneberger et al. 2012, Smith et al. 

2013). A brief overview of the five main categories of agroforestry practices used in the United States, with a growing sixth 

category—special applications—for agroforestry technologies 

being adapted to address emerging needs across rural/urban 

landscapes, is presented in figure 1.1 and table 1.1. 

Although practice categories offer a useful frame of reference 

for describing agroforestry, in application it can take on many 

variations and combinations—from only a few trees within a crop 

field to highly integrated, multistoried food forests—depending on 

the products and functions being sought. The permutations and 

the terminology used to describe them are often quite varied, 

especially for agroforestry within tribal and island communities.

To illustrate the large continuum of agroforestry practices, examples in box 1.1 show the different combinations of practices 

in greater detail. Additional information on these agroforestry 

practices within North America can be found in Garrett (2009).

Agroforestry has been identified as a multifunctional landuse approach that can balance the production of commodities 

with noncommodity outputs such as environmental protection 

and cultural and landscape amenities (McIntyre et al. 2009). 

Evidence suggests that agroforestry can sustainably increase 

production per unit of land area while maintaining or enhancing 

other economic, social, and environmental services (Asbjornsen 

et al. 2014, Olson et al. 2000, Smith et al. 2013). Evidence also 

suggests that agroforestry can build adaptive capacity within 

agricultural operations and support greenhouse gas (GHG) 

mitigation (CAST 2011, FAO 2013b, Matocha et al. 2012, van 

Noordwijk et al. 2014, Watson et al. 2000).

Like many other management options for building resiliency, 

agroforestry needs to be implemented proactively to reduce 

vulnerability to weather extremes and other climatic variabilitydriven impacts when they occur. Tree-based practices have 
2 Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions

Figure 1.1. Five main categories of agroforestry practices are used in the United States: (A) alley cropping, (B) windbreaks, 

(C) riparian forest buffers, (D) silvopasture, and (E) forest farming. An emerging sixth category is (F) special applications (e.g., short-rotation woody crops). (Photos by USDA Forest Service and USDA Natural Resources Conservation Service [A, B, C, D, F], and 

Catherine Bukowski, Virginia Tech [E]).

longer establishment periods, requiring planting several years 

before large-scale disturbances occur. The potential benefits 

currently valued by farmers and ranchers (e.g., enhanced yields 

and livestock production, water quality protection, biodiversity, productive soils, and diversification of production) are 

derived from the same agroforestry functions that are important 

for reducing threats and enhancing resiliency under changing 

conditions. These many benefits provide a mechanism for producers to offset any lost opportunity costs as they work towards 

building more resilient operations.

Agroforestry practices in the United States are not as well-studied and well-established as more conventional agronomic 

and forestry practices and will require some investment to

further our understanding of the impacts of changing conditions on agroforestry health and performance (Luedeling et al. 

2014). Most of our knowledge of agroforestry is derived from 

site- and field-scale studies at limited numbers of locations. 

Agroforestry systems are complex assemblages of ecosystem 

components, each of which may respond differently to climatic 

variability and other environmental changes. Although we 

A

C

E

B

D

F
Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions 3

Table 1.1. Categories of agroforestry practices in the United States.

Practice Descriptiona Primary benefits and usesb

Alley cropping (also 

called tree-based 

intercropping)

Trees or shrubs planted in sets of 

single or multiple rows with agronomic crops, horticultural crops, 

or forages produced in the alleys 

between the trees that can also 

produce additional products.

• Produce annual and higher value but longer term crops.

• Enhance microclimate conditions to improve crop or forage quality and quantity.

• Reduce surface water runoff and erosion.

• Improve soil quality by increasing utilization and cycling of nutrients.

• Enhance habitat for wildlife and beneficial insects.

• Decrease offsite movement of nutrients or chemicals.

Windbreaks (also 

includes shelterbelts)

Single or multiple rows of trees or 

shrubs that are established for environmental purposes; depending on 

the primary use, may be referred to 

as crop or field windbreak, livestock 

windbreak, living snow fence, farmstead windbreak, or hedgerow.

• Control wind erosion.

• Protect wind-sensitive crops.

• Enhance crop yields.

• Reduce animal stress and mortality.

• Serve as a barrier to dust, odor, and pesticide drift.

• Conserve energy.

• Manage snow dispersal to keep roads open or to harvest moisture.

Riparian forest buffersc An area of trees, shrubs, and 

herbaceous vegetation established 

and managed adjacent to streams, 

lakes, ponds, and wetlands.

• Reduce nonpoint source pollution from adjacent land uses.

• Stabilize streambanks.

• Enhance aquatic and terrestrial habitats.

• Increase C storage in plant biomass and soils.

• Diversify income either through added plant production or recreational fees.

Silvopasture Trees combined with pasture and 

livestock production.

• Produce diversification of livestock and plant products in time and space.

• Produce annual and higher value but longer term products.

• Reduce nutrient loss.

Forest farming (also 

called multistory 

cropping)

Existing or planted stands of trees 

or shrubs that are managed as an 

overstory with an understory of 

plants that are grown for a variety of 

products.

• Improve crop diversity by growing mixed but compatible crops having different 

heights on the same area.

• Improve soil quality by increasing utilization and cycling of nutrients.

• Increase C storage in plant biomass and soil.

Special applications Use of agroforestry technologies to 

help solve special concerns, such as 

disposal of animal wastes or filtering 

irrigation tailwater, while producing a 

short- or long-rotation woody crop.

• Treat municipal and agricultural wastes.

• Manage stormwater.

• Produce biofeedstock.

C = carbon.

a

 Descriptions follow USDA Natural Resources Conservation Service Practice Standards. http://www.nrcs.usda.gov/wps/portal/nrcs/main/national/technical/cp/ncps/.

b All agroforestry plantings add diversity within the agricultural landscape. In general, such plantings will enhance wildlife habitat in agricultural settings and are often 

designed or managed with doing so as a secondary benefit.

c

 Riparian forest buffer refers to the planted practice. This category does not include naturally established riparian forests.

capitalize on it to attain agroforestry’s benefits, this inherent 

complexity makes it difficult to accurately predict, at this time, 

impacts from changing conditions. A broader understanding of 

how these agroforestry practices function is needed to enhance 

our ability to provide reliable regional and local assistance, and 

gaining that understanding will require an adaptive management approach.

This report offers a first-ever scientific assessment of agroforestry’s potential in the United States to provide mitigation and 

adaptation services under changing conditions. Based on available scientific evidence, agroforestry can contribute to these 

services by sequestering carbon, reducing GHG emissions, 

enhancing resiliency, and reducing threats while facilitating 

migration of wildlife and aquatic species to more favorable 

conditions (table 1.2). One of the primary strengths of agroforestry that emerged from this assessment is the opportunity 

to provide integrated mitigation and adaptation services in a 

synergistic manner (Duguma et al. 2014) while also supporting 

expanding food security goals and limiting environmental impacts. Agroforestry-induced diversification of income streams 

and other ecosystem services can help safeguard agricultural 

production under the many uncertainties from climatic variability to shifting markets.
4 Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions

Box 1.1. The Practice of Agroforestry

Agroforestry represents a wide-ranging continuum of managed 

woody plant, herbaceous crop, and livestock combinations—

from a few trees planted within industrial, commodity operations 

to stratified native forests manipulated for food and other 

products. This diversity can create some confusion regarding 

what agroforestry actually is and what it means.

As a general rule, when agroforestry is placed into a land use, 

it does not convert the land use. It is not considered afforestation (based on its small size); rather, it is the use of tree-based 

plantings in support of agricultural land use or, in the case 

of forest farming, in support of forest land use. Agroforestry 

within U.S. farm or ranch operations, in general, is only a few 

plantings, comprising a small portion of the land area.

The definition of agroforestry implies deliberate and integrated 

management of tree, crop, and livestock components. 

Therefore low- to no-management applications, such as 

tribal and island plantings or Southwest woodland grazing, 

represent a gray area (see chapter 5 and box A.1). Some of 

these systems currently do not meet the strict definition of 

agroforestry. However, management may be 

required in these systems in the future to 

enhance or maintain ecosystem service 

production under changing conditions. 

With this addition of management, 

those systems may then meet the 

criteria under the current definition 

of agroforestry.

Is it an agroforestry system or practice? 

Agroforestry is often described in many ways; as a system, 

a practice, and even a management activity and a planting. 

Although these terms are used interchangeably, a distinction 

between a system and a practice is worth mentioning. System

connotes the many parts, arrangements, and interactions 

created by integrating these parts; it is a familiar term within 

the scientific community. In the agricultural community, however, 

the use of practice is better understood and more compatible 

with other agricultural practices (Gold and Garrett 2009).

Agroforestry category and practice, while also used interchangeably, can provide a means for acknowledging subgroups. In this case, the five main agroforestry practices (table 

1.1) can be referred to as categories, allowing some groups, 

like windbreaks, to be further defined based on specific 

use (e.g., field windbreaks, farmstead windbreaks, livestock 

windbreaks).

Additional terms such as agroforest and homegarden are 

used in this assessment, which also includes a 

glossary—an invaluable tool for navigating the 

terminology surrounding agroforestry. The 

terminology can be confusing; however, it 

reflects the diversity, the versatility, and 

therefore the potential of agroforestry 

to play an increasing role in climate 

change adaptation strategies.

Agroforestry represents a fluid continuum among trees, crops, and livestock, ranging 

from a few trees established within a field or pasture to multistory forests managed 

for a variety of products. The five agroforestry categories are well-established terms 

in the conterminous United States, with each practice having the potential to vary 

depending on its design within these continuums. Terms, such as homegarden and 

agroforest, which are more commonly used and recognized outside the conterminous United States (e.g., the islands and Mexico), are slowly growing in use in the 

United States. (Figure adapted from den Herder et al. 2015.)
Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions 5

Table 1.2. Agroforestry functions that support climate change mitigation and adaptation.

Climate change 

activity

Major climate 

change functions

Agroforestry functions that 

support climate change mitigation and adaptation

Adaptation

Actions that reduce or 

eliminate the negative 

effects of climate change 

or take advantage of the 

positive effects.

Reduce threats and enhance 

resilience.

• Alter microclimate to reduce impact of extreme weather events on crop production.

• Alter microclimate to maintain quality and quantity of forage production.

• Alter microclimate to reduce livestock stress.

• Provide greater habitat diversity to support organisms (e.g., native pollinators, 

beneficial insects).

• Provide greater structural and functional diversity to maintain and protect natural 

resource services.

• Create diversified production opportunities to reduce risk under fluctuating climate.

Facilitate plant species movement 

to more favorable conditions.

• Assist in plant species migration through planting decisions.

Allow species to migrate to more 

favorable conditions.

• Provide travel corridors for species migration.

Mitigation 

Activities that reduce 

GHGs in the atmosphere or enhance 

the storage of GHGs 

stored in ecosystems.

Sequester C • Accumulate C in woody biomass.

• Accumulate C in soil.

Reduce GHG emissions • Reduce fossil fuel consumption:

o with reduced equipment runs in areas with trees.

o with reduced farmstead heating and cooling.

• Reduce N2O emissions: 

o by greater nutrient uptake through plant diversity.

o by reduced N fertilizer application in tree component.

• Enhance forage quality, thereby reducing CH4.

C = carbon. CH4 = methane. CO2 = carbon dioxide. GHG = greenhouse gas. N = nitrogen. N2O = nitrous oxide.

Source: Modified from Schoeneberger et al. (2012).

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Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions 7

Chapter 2

Reducing Threats and Enhancing Resiliency

Michael G. Dosskey, Jim Brandle, and Gary Bentrup

Michael G. Dosskey is a research ecologist (retired), U.S. Department of Agriculture (USDA), Forest 

Service, USDA National Agroforestry Center; Jim Brandle is the emeritus shelterbelt ecologist, University 

of Nebraska, School of Natural Resources; Gary Bentrup is a research landscape planner, USDA Forest 

Service, USDA National Agroforestry Center.

Contributors: Andrew C. Bell, Sid Brantly, Adam Chambers, Craig Elevitch, Michael Gold, 

Jason Griffin, Kayri Havens, Shibu Jose, Thomas Sauer, Ranjith Udawatta, and Diomy Zamora

Andrew C. Bell is a Longwood fellow, Longwood Gardens, and visiting scientist, National Arboretum; Sid 

Brantly is the national rangeland management specialist (retired), USDA Natural Resources Conservation 

Service; Adam Chambers is an air quality specialist, USDA Natural Resources Conservation Service, National 

Air Quality and Atmospheric Change Team; Craig Elevitch is the director of agroforestry Net; Michael Gold

is the associate director of the Center for Agroforestry, University of Missouri; Jason Griffin is an associate 

professor of nursery crops and the director of the John C. Pair Horticultural Center, Kansas State University; 

Kayri Havens is the Director of Plant Science and Conservation, Chicago Botanic Garden; Shibu Jose is 

the director of the School of Natural Resources, University of Missouri; Thomas Sauer is a research soil 

scientist, USDA Agricultural Research Service, National Laboratory for Agriculture and The Environment; 

Ranjith Udawatta is an associate research professor, University of Missouri, School of Natural Resources; 

Diomy Zamora is an extension professor of forestry, University of Minnesota Extension.

Adaptive Capacity of U.S. Agriculture

Assessments of climate change in the United States and of its 

impacts on U.S. agriculture (Melillo et al. 2014, Walthall et al. 

2012) conclude that it is very likely that climate is changing in 

the United States and will continue to change throughout the 

21st century. According to those assessments, temperatures 

will become generally warmer, but variability within seasons 

will become greater in some regions; precipitation patterns will 

change, becoming generally wetter or drier, depending on the 

region; and a higher incidence of extreme weather events, including 

drought, heat waves, and periods of intense rainfall, is likely.

Changes in climate patterns and weather variability pose 

substantial hazards for current U.S. agricultural systems and the 

resource base (fig. 2.1). According to an assessment of U.S. agriculture (Walthall et al. 2012), yield of crops and livestock will 

decline in some regions and increase in others due to changes 

in regional average climate conditions, extreme weather events 

outside optimum growth and reproductive ranges, and shifting 

ranges of damaging pests; crop growth (and that of weeds, 

too) may increase in response to higher atmospheric carbon 

dioxide (CO2

), but the quality of some crops may be reduced; 

soil erosion and water pollution will increase; and the quality of 

habitat for supporting beneficial biodiversity such as pollinators 

will decline.

The pace and complexity of changing conditions are likely to 

overwhelm the ability of current systems to adapt and sustain 

current levels of output in the long term (Walthall et al. 2012). 

New technologies will be needed to avoid significant disruptions 

in agriculture. This chapter assesses the potential for agroforestry to help adapt agriculture and agricultural lands to threats 

from climate change. Agroforestry practices blend trees and 

shrubs into the agricultural landscape to modify landscape 

structure in specific ways (fig. 2.2). Structure provided by 

agroforestry practices can be designed to modify microclimate 

to ameliorate direct impacts of weather extremes on production 

systems; to provide additional opportunities for crop production; and to protect and enhance key resources such as soil, 

water, and biodiversity on which agricultural production and 

other ecosystem services depend.
8 Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions

Figure 2.1. Agricultural productivity in the United States faces the potential for severe disruption because of climate change. To 

sustain a high level of productivity and a healthy resource base, agricultural systems will need to adapt to changing conditions. 

(A) Rice harvest in California. (Photo by Gary Kramer, USDA Natural Resources Conservation Service). (B) Cattle grazing in Alabama. 

(Photo by Steven Kirkpatrick, USDA Natural Resources Conservation Service).

Figure 2.2. Agroforestry reduces climate-related threats to agriculture by modifying the structure of agricultural landscapes. 

Through landscape structure, agroforestry practices modify microclimate, stabilize soil, protect water and air quality, and provide 

for biological diversity, including the diversity of agricultural crops. Each general type of agroforestry practice (see chapter 1) represents a different structural template for emphasizing certain benefits over others. All agroforestry practices, however, are capable 

of providing, and likely will provide, multiple benefits in any agricultural landscape. (Figure from Dosskey et al. 2012, as modified 

from MEA 2005).

Commodity Production

Many benefits of agroforestry are derived from how it modifies 

local environmental conditions (e.g., air and soil temperatures, 

humidity, evaporation, windspeed, turbulence). Through 

agroforestry, local microclimate can be manipulated to enhance 

productivity of adjacent agricultural fields and pastures and to 

provide other environmental benefits.

Incorporating woody vegetation into the landscape reduces 

windspeed across the land surface, provides shade from solar 

radiation during the day, reduces radiative cooling at night, and 

recycles water from the soil (Brandle et al. 2009, Stigter 2010). 

These effects lead to physiological and ecological changes in 

the biological components of the agricultural landscape.

A B
Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions 9

The structure of the agroforestry practice determines the 

magnitude of change in windspeed or radiation load (Barnes 

et al. 1998, Heisler and Dewalle 1988, Zhou et al. 2005). By 

manipulating the density and arrangement of the tree canopy, 

the wind flow patterns and radiation loads can be modified for 

the benefit of nearby crop fields and pastures (Brandle et al. 

2009, McNaughton 1988). Evaporation from the soil surface 

is reduced, leaving more moisture for crop growth (Brandle 

et al. 2009). Water use efficiency is increased (Davis and 

Norman 1988). Soil temperatures tend to be warmer (Hodges 

et al. 2004) and humidity tends to be higher (McNaughton 

1988). Daytime air temperatures tend to be warmer near the 

trees because of disruption of large-scale turbulence but tend 

to be cooler farther away (Cleugh 2002, McNaughton 1988). 

Agroforestry systems capitalize on these effects to benefit both 

crop and livestock production.

Future climate is expected to be warmer and drier in many 

agricultural regions; drought is a major concern (Walthall et 

al. 2012). Irrigation restrictions already are common in the 

Western United States (Schaible and Aillery 2012). Through 

microclimate modification, agroforestry practices, such as 

windbreaks, alley cropping, and silvopasture, can help crops 

and livestock use limited water more efficiently and thus 

ameliorate the effects of climate change.

Agroforestry practices vary in structure and design and, consequently, in their effects on microclimate. Garrett (2009) provides 

a comprehensive and detailed review of different agroforestry 

practices and their associated microclimate effects. Chapters 

include discussions of windbreaks (Brandle et al. 2009), 

silvopasture systems (Sharrow et al. 2009), and alley cropping 

systems (Garrett et al. 2009). The major conclusions of these 

chapters regarding how agroforestry practices affect crop and 

livestock production are presented in the following sections.

Crop Production

The effect of windbreaks (fig. 2.3) on the yield of conventional 

crops has been well documented worldwide (Baldwin 1988, 

Brandle et al. 2009, Kort 1988). Yield improvements can 

be substantial, although results vary by crop, location, and 

year (table 2.1). For example, under windy conditions, when 

moisture is limited, shelter provides positive benefits for both 

quality and quantity of grain, forage, and vegetable crops. The 

yield benefit from a windbreak to crops in the field area more 

than offsets the decrease in yield from the area planted to trees 

(fig. 2.4). The precise mechanisms that produce this benefit can 

vary, but all are related to wind reduction and radiation control 

by the windbreak. For example, in Nebraska, overwintering 

wheat plants (Triticum aestivum) are protected from winter 

desiccation (Brandle et al. 1984, 1992). In Mediterranean 

environments, wheat yield increases are attributed to improvement in water use efficiency (Campi et al. 2009). In Australia, 

Figure 2.3. A windbreak of conifer trees provides year-round 

protection from wind for this cropland in Indiana. (Photo by Erwin C. Cole, USDA Natural Resources Conservation Service).

Table 2.1. Yield of many different crops can be increased by 

providing shelter with windbreaks. 

Crop Average yield increase (%)

French beans 6

Oats 6

Potatoes 6

Spring wheat 8

Dry beans 10

Maize 12

Soybeans 15

Tomatoes 16

Rye 19

Grass hay 20

Winter wheat 23

Barley 25

Raspberry 40

Snap beans 40

Millet 44

Strawberry 56

Source: Data from Baldwin (1988), Brandle et al. (2009), and Kort (1988).

Figure 2.4. The generalized profile of crop yield response 

to field windbreaks in the Great Plains. (Figure adapted from 

Read 1964 and Brandle et al. 2009).
10 Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions

the principle benefit of windbreaks was their ability to reduce 

wind erosion and subsequent crop damage (Sudmeyer et al. 

2002, Sudmeyer and Flugge 2005).

Modeling studies by Easterling et al. (1997) using the 

Erosion-Productivity Impact Calculator and Mize et al. (2008) 

using the Shelterbelt Agroforestry Modeling System indicate 

that windbreaks have the potential to increase yields over 

unprotected fields under all but the most extreme scenarios 

predicted by climate models. Lower nighttime temperatures 

resulting from reduced windspeed, less mixing of the air, and 

reduced evapotranspiration are thought to account for most 

of the yield gains in sheltered crops (Easterling et al. 1997, 

Hatfield et al. 2011).

High winds during drought periods can also decrease yields 

because of abrasion to crop plants from blowing soil (Armbrust 

1982, Finch 1988, Sudmeyer et al. 2002, Sudmeyer and Flugge 

2005). Under a future warmer and drier climate, drought periods 

are expected to become more frequent and more extreme (Vose 

et al. 2016). Abrasion damage is a particular problem with 

production of fruit and vegetable crops (Norton 1988). In many 

cases, replanting becomes necessary, requiring additional 

inputs and expense. Wind control by agroforestry practices 

(windbreaks, riparian buffers, and alley cropping systems) can 

be effective at minimizing blowing soil. Properly designed 

windbreaks, for example, are effective to a distance from the 

windbreak of 10 times the height of the trees (USDA-NRCS 

2014). Windblown soil particles in the air (dust) also degrade 

air quality and can create serious health issues for people, livestock, and wildlife (Williams and Young 1999), as explained in 

the section on Air Quality in this chapter.

In the longer term, erosion of soil by wind removes the finer 

soil particles, organic matter, and nutrients, which leads to 

reduced soil health. Furthermore, soil that is blown off site 

is deposited in lakes, reservoirs, and road ditches, requiring 

mitigation efforts. The economic costs associated with offsite 

impacts of blown soil can exceed the onsite costs of yield reduction from crop damage and soil loss (Huszar and Piper 1986).

Shade from agroforestry practices can help limit heat stress and 

improve yields of some crops. Crops such as cotton (Gossypium 

hirsutum) and soybean (Glycine max) have higher rates of 

field emergence when grown under moderated temperatures. 

Cotton exhibits earlier germination and higher survival rates 

when grown in the shade of pecan trees, where conditions 

are cooler and moister (Jose et al. 2004). Moderate shade can 

also improve growth in some crops; for example, two species 

of woody ornamentals, American beautyberry (Callicarpa 

americana var. lactea) and parsley hawthorn (Crataegus 

marshallii) have higher survival and faster growth under pecan 

alley cropping compared with monoculture (Fletcher et al. 

2012). Warm-season legumes, hoary ticktrefoil (Desmodium 

canescens) and panicledleaf ticktrefoil (D. paniculatum) produce 

significantly greater dry weight and some forage species contain 

more crude protein when grown at 50 percent and 80 percent 

shade than in full sunlight (Lin et al. 1999, 2001). Shading and 

competition with trees for water and nutrients, however, can 

also negatively affect the yield of some crops. On the balance, 

Gillespie et al. (2000) saw no effect on corn yield in two alley 

cropping systems in Indiana. To adapt to future hotter climate, 

it will be important to identify and select effective combinations of agroforestry tree and crop species that capitalize on 

microclimate modification.

Livestock Production

Predicted higher temperatures may pose a significant challenge in animal production systems. Elevated temperatures, 

especially when combined with high humidity, will reduce 

weight gain, pregnancy rates, and milk production and will 

also lower overall animal health (Walthall et al. 2012). In 

beef cattle operations, heat is a significant factor in biological 

efficiency (Gaughan et al. 2010, Tucker et al. 2008). For 

example, a reduction in deep body temperature of beef cattle by 

as much as 0.77 °C can improve gain rates by as much as 0.57 

kilograms per day during summer heat stress periods (Higgins 

et al. 2011).

Providing shade is a recommended strategy for reducing 

summertime heat stress on livestock under a warming climate 

(Rowlinson 2008). Shade also helps improve milk yields, 

increase conception rates, and decrease mastitis in dairy cattle 

(Gregory 1995, Tucker et al. 2008). Shade is important for 

reducing heat load from direct sunlight, particularly in cattle 

with dull, dark hair coats (da Silva et al. 2003). Provision of 

shading using agroforestry practices may offset the effects of 

projected temperature increases on livestock production. By 

providing shade, silvopasture and livestock windbreaks can 

reduce the energy expended for thermoregulation, leading to 

higher feed conversion and weight gain (Brandle et al. 2009, 

Sharrow et al. 2009). Mitlöhner et al. (2001) found that cattle 

provided with shade reached their target body weight 20 days 

earlier than those without shade.

Increasing atmospheric CO2

 concentration may reduce the 

quality of livestock forages produced on grazing and pasture 

lands (Walthall et al. 2012). Higher levels of CO2 will increase 

forage production but reduce overall forage quality because 

of the effects on plant nitrogen and protein content (Morgan 

et al. 2004). Shading, however, can increase forage quality, 

depending on the forage species (Lin et al. 2001). For instance, 

the shading component in silvopasture systems has been shown 

to improve forage quality in cool-season grasses by increasing 

protein content while reducing fiber (Bambo et al. 2009, 

Kallenbach et al. 2006). Higher forage quality combined with 
Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions 11

shading to reduce animal heat stress suggests that silvopasture 

systems can be a viable strategy to sustain livestock production 

under climate change (Schoeneberger et al. 2012).

In some regions, such as the Central United States, periodic 

winter cold events are likely to become more extreme under a 

future climate (Kim et al. 2014) and threaten livestock production. Low temperatures, especially when combined with wind, 

decrease livestock production efficiency by requiring greater 

feed intake to maintain body temperature. The consequences 

of extreme cold events can create challenges to producers, exemplified by the October 2013 storm that resulted in the deaths 

of more than 45,000 livestock in South Dakota (Edwards et al. 

2014). Reducing windspeed in winter by using agroforestry 

practices, particularly windbreaks, can lower livestock stress, 

improve livestock health, and increase feeding efficiency (Brandle 

et al. 2009, Gregory 1995). Winter protection can be especially 

critical for young lambs and calves during lambing or calving 

season. Cattle producers in Kansas indicate, on average, calving 

success increases by 2 percent if a windbreak protects the cows 

(Quam et al. 1994).

Key Findings

Agroforestry practices can improve the productivity of 

conventional agricultural crops and livestock by enhancing 

the microclimate around them and, thereby, may ameliorate 

negative effects of climate change on agricultural production.

Key Information Needs

• Improved models for predicting effects of agroforestry 

practices on crop yields under future climate scenarios.

• Identification of agroforestry tree and crop combinations that 

capitalize effectively on microclimate modification.

• Better documentation of forage and livestock yield responses 

in silvopasture systems.

• Revised agroforestry designs tailored to modern field 

geometries and management practices.

Crop Diversity

Annual grain and oil-seed crops comprise the bulk of U.S. 

food and feed crop production and will continue to do so for 

much of the 21st century (Malcolm et al. 2012). In response to 

climate change, shifts in acreages for specific crops, changes 

in management decisions, and expansion of irrigation may 

compensate for some loss in yields in the short term (Walthall 

et al. 2012). Advances in plant breeding and development of 

genetically modified crops offer opportunities to develop crops 

more tolerant of drought and heat stress; however, most of our 

annual crops will remain particularly vulnerable. Maintaining 

annual crop production will become increasingly problematic, 

and the combined stresses associated with climate change are 

expected to decrease overall agricultural productivity in the 

second half of this century (Pryor et al. 2014, Walthall et al. 

2012) (table 2.2).

Table 2.2. Percent change in U.S. production (averaged across 

climate change scenarios) relative to reference conditions. 

Crop Average percent change in production

2020 2040 2060 2080

Barley (bushels) – 1.9 – 0.6 – 3.5 1.0

Corn (bushels) – 8.1 – 8.7 – 13.8 – 16.2

Cotton (bales) – 7.9 – 6.1 – 5.6 – 5.9

Hay (dry ton) – 4.0 – 0.6 2.7 4.2

Oats (bushels) – 8.7 – 10.7 – 16.1 – 20.8

Rice (cwt) – 2.2 – 2.5 – 4.2 – 6.1

Silage (dry ton) – 6.9 – 9.5 – 13.1 – 14.4

Sorghum (bushels) – 15.1 – 5.4 – 14.0 – 17.0

Soybeans (bushels) – 8.1 – 8.8 – 11.9 – 14.3

Wheat (bushels) – 2.8 1.3 5.6 11.6

cwt = hundredweight.

Source: USDA-ERS (2015b).

Agroforestry practices may be capable of both mitigating the 

negative impacts of climate stressors on annual crop production 

and serving as resilient food production systems (Lin 2011, 

Matocha et al. 2012, Schoeneberger et al. 2012, Van Noordwijk 

et al. 2014, Verchot et al. 2007). Agroforestry food crops offer 

opportunities to replace production of annual grain and oil-seed 

crops on acres converted to agroforestry practices (fig. 2.5).

Agroforestry systems are multispecies mixes of perennials and 

annuals that are inherently more resilient to environmental 

stresses than annual-only cropping systems (Leakey 2014, 

Malézieux 2012, Smith et al. 2013). They have a higher degree 

Figure 2.5. Agroforestry practices providing protection for 

annual crops and natural resources can be implemented with 

species that produce an additional crop, like this cherry crop 

in Michigan. (Photo by Lynn Betts, USDA Natural Resources 

Conservation Service).
12 Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions

of species diversity, larger root systems that hedge against 

climate extremes, and the ability to tolerate increased disturbance (Helzer 2010, Jose et al. 2009). Where winter chilling 

requirements do not become limiting, food-producing perennial 

crops such as fruits, nuts, and berries can provide resilience to 

climate extremes. Species mixes spread biological and financial 

risks across crops and seasons. Many agroforestry crops are 

also better suited to being grown on marginal lands than are 

annual crops (MacDaniels and Lieberman 1979, Molnar et al. 

2013, Smith et al. 2013).

The production of specialty crops that can be grown in agroforestry systems is increasing in direct response to increasing 

demand for locally sourced foods (Johnson 2014, Low and 

Vogel 2011, USDA-ERS 2015a). Fruit, nut, and vegetable 

farms are eight times more likely to sell locally than are other 

farms (Low and Vogel 2011). According to statistics collected 

by the USDA Agricultural Marketing Service, the number 

of farmers markets has increased from 1,755 to more than 

8,284, reflecting a 372-percent increase since 1994 (fig. 2.6) 

(USDA-ERS 2014). Agroforestry food crops can contribute to 

increasingly popular direct-to-consumer food systems.

Figure 2.6. Growth of local farmers markets are increasing 

the demand for specialty food crops, including agroforestry 

crops, and creating new marketing opportunities. (From USDA 

Economic Research Service using USDA Agricultural Market 

Service’s Farmers Market Survey).

Agroforestry food systems are notable historically for their 

sustainability and resilience. For example, multistory food-producing systems have sustainably produced fruit, nuts, leafy 

vegetables, and other staple foods since ancient times (Ewel 

1999, Wiersum 2004); tropical and subtropical agroforestry 

homegardens have demonstrated sustainable production for 

thousands of years (Torquebiau 1992, Vandermeer et al. 

1998); and multistory agroforestry homegardens have been 

traditionally cultivated in temperate environments for at least 

two millennia (Clark and Nicholas 2013, Lelle and Gold 1994, 

Smith 1950).

Agroforestry is a form of multifunctional agriculture (Jose 

2012, Leakey 2014, McIntyre et al. 2009, Picasso et al. 2011, 

Quinkenstein et al. 2009, Robertson et al. 2014, Van Noordwijk et al. 2011). When properly designed and maintained, 

food-producing agroforestry systems can simultaneously 

provide ecological services that annual crops do not, such 

as reducing nonpoint source pollution, sequestering carbon, 

sustaining long-term soil fertility, and enabling biological 

control through crop and ecosystem diversity (Batello et al. 

2014, Clough et al. 2011, Davis et al. 2012, Ewel 1999, Jose 

2012, Robertson et al. 2014, Schoeneberger et al. 2012).

The integration of food- and commodity-producing perennials 

into agroforestry practices has the potential to add millions of 

hectares to the production base of the United States without 

loss of protection of environmentally sensitive lands (Jose et 

al. 2012). Agroforestry practices like alley cropping, windbreaks, and riparian forest buffers can be designed to include 

food-producing species (e.g., fruits, nuts) (Schultz et al. 2009, 

Smith et al. 2013). Nonfood crops such as floriculture, biomass, 

and timber crops can also be incorporated into these practices 

(Schultz et al. 2009). Agroforestry production systems can 

produce greater total yields per unit area as compared with 

monocultures of the individual crops they include (Dupraz et 

al. 2005). The combination of diversified food and commodity 

production and provision of ecosystem services can impart 

greater economic and biological resilience to the effects of 

climate change than can conventional annual cropping systems.

If widely deployed, agroforestry practices scattered across the 

agricultural landscape can function as a patchwork of mosaics 

at different stages of maturity (early, mid, late) (Robertson et 

al. 2014, Subler and Uhl 1990), adding further resilience to the 

agroecosystem. Well-designed landscape mosaics can further 

spread economic and ecological risk and may lower some costs 

of production (Clark and Nicholas 2013, Smith et al. 2013).

Key Findings

• Agroforestry systems incorporating appropriate species can 

be significant food production systems.

• Food-producing agroforestry systems are more resilient to 

climate stressors than are annual cropping systems.

• Agroforestry systems can diversify farm portfolios, spread 

risk, and increase both the economic and environmental 

resilience of farms.

Key Information Needs

• Improved agroforestry systems for marginal and degraded lands.

• Identification of agroforestry tree and crop combinations 

that maximize positive interactions while minimizing 

competitive interactions between crops and trees.
Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions 13

• Better strategies for producing, distributing, and marketing 

food and nonfood products from agroforestry systems.

Soil Resources

Climate change is predicted to include more frequent extreme 

rainfall events and longer drought periods, which would affect 

soil resources (Melillo et al. 2014). Increased precipitation 

intensity will lead to an exponential increase in the potential 

for soil erosion by water runoff (Garbrecht et al. 2014). Longer 

drought periods will increase the period of susceptibility of 

soils to erosion by wind (Nordstrom and Hotta 2004). Topsoil 

loss to erosion will reduce the health and productivity of 

the remaining soil resource and threaten the sustainability 

of agricultural production (Walthall et al. 2012) (fig. 2.7). 

Figure 2.7. Soil erosion by water and wind jeopardizes soil 

health and the sustainability of agricultural productivity. Climate 

change is predicted to exacerbate conditions that lead to soil 

erosion. (A) Severe sheet and rill erosion on highly erodible 

soils in Iowa after heavy rains. The spring rains fell on soils that 

had no protection against soil erosion. (Photo by Lynn Betts, 

USDA Natural Resources Conservation Service). (B) Some agricultural regions currently experience high rates of soil erosion 

by water (blue dots) and wind (red dots). Each dot represents 

100,000 tons per year. Soil erosion is expected to accelerate 

in response to climate change in most regions. (Data and map 

from 2010 USDA National Resources Inventory, USDA Natural 

Resources Conservation Service).

Appropriate agroforestry practices can reduce these threats by 

protecting soils from water and wind erosion and by rebuilding 

soil health in eroded soils (Jose 2009, Young 1989).

Soil Erosion

Most soil erosion in agricultural fields occurs during large 

rainfall events. When the rainfall rate exceeds the infiltration 

capacity of soil, the excess water drains overland, dislodging 

topsoil and carrying it off the field. Soil erosion is accentuated 

by annual tillage that loosens the topsoil, reduces infiltration 

capacity, and removes surface debris that protects soil from 

being dislodged by raindrops and overland flow. Under current 

climate conditions, the average rate of soil erosion from tilled 

agricultural fields is much greater than the rate of soil regeneration leading to a substantial net loss of soil (Montgomery 

2007). Under a future climate, greater frequency of extreme 

rainfall events will exacerbate this problem. At a national scale, 

soil erosion by rainfall is estimated to increase between 16 and 

58 percent during the 21st century because of climate change 

(Nearing 2001, Nearing et al. 2004). Others have predicted 

similarly large increases in erosion rate (O’Neal et al. 2005, 

Segura et al. 2014).

Agroforestry practices such as alley cropping can markedly 

reduce the rate of soil erosion from crop fields and potentially 

counteract the increasing risk of erosion posed by climate 

change. An alley cropping system can be oriented and designed 

to stabilize soil and promote infiltration within the tree strips 

and to reduce the erosive force of overland flow across the 

cultivated field. Sediment outflow from fields with alley 

cropping has been measured to be 28 to 30 percent less than 

from fields without alley cropping (Udawatta et al. 2011b).

In drier regions of the United States, like the Great Plains, soil 

erosion by wind can be significant during drought periods. This 

region historically has experienced severe soil loss by wind 

erosion, such as experienced during the Dust Bowl years in 

the 1930s. The prospect of increasing length and severity of 

drought periods due to climate change raises the risk that periods of severe wind erosion may recur with greater frequency.

Of all the potential benefits of a windbreak agroforestry 

practice, wind erosion control is the most widely recognized 

and accepted (Brandle et al. 2009). The link between windspeed and wind erosion is well established. Properly designed 

windbreaks reduce windspeed near the ground surface (as 

described previously in the Commodity Production section) and 

significantly reduce wind erosion. In response to the Dust Bowl 

experience, soil conservation efforts established nearly 19,000 

miles of windbreaks in the Great Plains (Droze 1977) (box 2.1). 

The success of that program led to similar efforts elsewhere in 

the United States and Canada and also in Argentina, Australia, 

China, New Zealand, and Russia (Cleugh et al. 2002, Mattis 

A

B
14 Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions

1988, Miller et al. 1995, Peri and Bloomberg 2002, Sturrock 

1984, Zhao et al. 1995). In the United States, however, most of 

the original windbreaks have been, and continue to be, removed 

as modern fields have increased in size and have changed 

shape to accept pivot irrigation systems. Where windbreaks 

have been removed, other techniques, such as conservation 

tillage and residue management, would be needed to limit 

wind erosion on a short-term basis, but they cannot replace the 

benefits of long-term perennial plantings.

Box 2.1. Prairie States Forestry Project

Current wind erosion and airborne dust problems are likely 

to increase under climate change (see Soil Resources and 

Air Quality sections). The U.S. Government used agroforestry 

to address these same issues during the Dust Bowl period 

of the 1930s on the Great Plains, when millions of acres 

of farmland were literally being blown away. The persistent 

drought, poor soil management, and subsequent wind 

erosion in the region had far-reaching social, economic, and 

environmental impacts. Soil was lost at a tremendous rate 

and many farmers and ranchers were forced from their land, 

leading to the largest human migration in American history 

within a short period of time. Between 1930 and 1940, 

approximately 3.5 million people moved away from the Plains 

States (Worster 1979). Dust pneumonia, a form of lung 

disease, affected many residents in the region. The worst 

duststorms reached the east coast and blanketed cities such 

as Chicago and New York in “black snow.”

In 1935, President Franklin D. Roosevelt initiated the Prairie 

States Forestry Project to combat the severe soil erosion. 

For the next 8 years, the U.S. Department of Agriculture, 

Forest Service, working with the Works Progress Administration (WPA) and Civilian Conservation Corps (CCC), planted 

windbreaks throughout the Great Plains States of Kansas, 

Nebraska, North Dakota, Oklahoma, South Dakota, and 

Texas. Although WPA and CCC workers planted the trees 

and shrubs, landowners were responsible for long-term 

care and maintenance of the windbreaks. Most of these 

windbreaks were 10 to 16 rows wide and a mile long. Even 

under the dry conditions of the time, most seedlings survived 

and, for the next 30 to 40 years, provided protection to 

the agricultural lands of the region. Nearly 220 million 

seedlings were planted, creating 18,600 miles of windbreaks 

occupying 240,000 acres on 30,000 farms (Williams 2005). 

Although many of these original windbreaks still exist 

around farmsteads, most of the wide-row field windbreaks 

have been removed to make way for center-pivot irrigation 

systems or field consolidation.

The Prairie States Forestry Project represents one of the 

largest and most focused efforts of the U.S. Government 

to address an environmental problem and is considered by 

some as a potential model for an effective climate change 

strategy (Sauer 2010). Viewed by modern standards, the 

A giant duststorm rolls across eastern Colorado during the 1930s. 

(Photo by USDA Natural Resources Conservation Service).

Workers planting a windbreak in the Great Plains during the mid1930s. (Photo by USDA Forest Service).

Landowners tending to their windbreak planted as part of the 

Prairie States Forestry Project during the 1930s. (Photo by USDA 

Forest Service).

project was conceived, designed, and implemented in a 

short period of time and incorporated effective top-down and 

bottom-up management styles. Although climate change is 

a more complex and global phenomenon than was the Dust 

Bowl, this past experience may hold important lessons for 

the current climate change problem.
Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions 15

Soil Health and Productivity

The erosion of fertile topsoil reduces soil productive capacity. 

Eroded topsoil consists of fine soil particles containing organic 

matter and nutrients. What remains is subsoil that has poorer 

physical, chemical, and microbiological properties for crop 

growth (Pimentel et al. 1995, Williams et al. 1981). Trees, 

shrubs, and grasses within agroforestry systems affect properties of soil directly beneath and adjacent to them. Compared 

with monocultured annual crops, perennial agroforestry vegetation can more quickly build and sustain higher levels of soil 

organic matter and nutrient content and create more favorable 

soil physical conditions for plant growth (Berg and Laskowski 

2006, Cadisch and Giller 1997, Udawatta and Anderson 2008, 

Udawatta et al. 2009). All these soil improvements link to 

recycling of organic matter provided by plant litter, roots, and 

root exudates and to decomposition processes influenced by 

agroforestry shading and wind reduction that alter soil temperature and water regimes.

Soils in agroforestry systems often have better structure for 

infiltration and water storage capacity than do soils in annually 

cultivated fields (Bharati et al. 2002; Seobi et al. 2005; Udawatta et al. 2006, 2011a). These characteristics will be critically 

important under a drier and warmer climate. Improved soil 

porosity is consistently observed within agroforestry systems 

that include riparian buffers, field windbreaks, alley cropping, 

and silvopasture practices (Bharati et al. 2002, Kumar et al. 

2010, Sauer et al. 2007, Seobi et al. 2005). Improved soil pore 

size distribution associated with perennial vegetation increases 

infiltration and water-holding capacity (Udawatta and Anderson 

2008, Udawatta et al. 2011a). These changes in soil structure 

and porosity are resilient to disturbances such as raindrop 

impact (Amezketa 1999, Bronick and Lal 2005).

Soil fertility and nutrient-use efficiency of crops can be 

improved by the presence of nearby agroforestry trees. 

Nutrients are captured from the subsoil by roots of trees and 

recycled to the soil surface through tree litter and, along with 

additional nitrogen fixed by leguminous agroforestry trees, 

can be recaptured by nearby crops (Blazier et al. 2008, Karki 

et al. 2009, Nair 1993). This process can reduce the need for 

intensive and frequent fertilizer additions. Reestablishment of 

nutrient-cycling processes creates a more diverse and resilient 

soil fertility system.

Microbial communities and soil enzymes under trees are functionally different than those under annual crops, which may 

improve nutrient availability and plant growth in alley cropping 

systems (Lacombe et al. 2009, Mungai et al. 2005, Rivest et 

al. 2010, Udawatta and Anderson 2008, Udawatta et al. 2009). 

Emerging research suggests that agroforestry systems can 

support higher microbial diversity than annual monocropped 

fields (Unger et al. 2013) and may have a positive effect on soil 

biochemical properties and microbial resilience that results in 

higher crop productivity and tolerance to severe water stress 

(Rivest et al. 2013).

Key Findings

• Agroforestry practices such as alley cropping and windbreaks 

can reduce soil erosion by water and wind and, thereby, 

protect long-term soil productivity.

• Agroforestry systems can enhance soil health by improving 

soil physical condition and fertility and by diversifying soil 

biological functions.

Key Information Needs

• Identification of optimal combinations of tree and crop 

species and spatial configurations for improving soil health, 

particularly on marginal or degraded lands.

• Better understanding of how to capitalize on below-ground 

structure and processes for improving water and nutrient 

uptake, especially under drought conditions.

• Documentation of crop productivity responses to agroforestryrelated soil improvements.

Water Resources

Water resources support crop and livestock production, and 

agricultural lands supply water for other uses, including 

wildlife and aquatic species, domestic consumption, energy 

production, and industrial and recreational purposes. Predicted 

increases in weather variability, including increasing frequency 

and intensity of heavy rainfall events and extended heat and 

drought periods, will affect water supply in ways that directly 

threaten agricultural production, infrastructure, and environmental quality (Melillo et al. 2014). Major impacts will include 

increasing drought stress on crops and livestock while water 

supplies for irrigation diminish, increasing flood and erosion 

damage to crops and supporting infrastructure, increasing water 

pollution by sediments and agricultural chemicals, accelerated 

sedimentation and diminishing water storage capacity in 

reservoirs for supply during drought and for flood control 

during storm events, and increasing water temperatures that 

degrade aquatic habitats (Bates et al. 2008, Brewer et al. 2014, 

Kundzewicz et al. 2014,Walthall et al. 2012, Whitehead et al. 

2009, Wilbanks and Fernandez 2012) (fig. 2.8).

Agroforestry practices can reduce drought stress and demand 

for irrigation water by moderating water use by crops and 

livestock, lessen the severity of flooding and stream channel 

erosion by moderating stream discharge and peak stormflows, 

reduce water pollution by sediments and agricultural chemicals 

by protecting soils in fields from erosion and by filtering these 
16 Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions

Figure 2.8. Water resources are expected to be affected by 

climate change in several ways. (A) Drought and heat stress 

in crops is expected to increase in severity. (Photo by Bob 

Nichols, USDA Office of Communications). (B) With climate 

change, flood damage to crops and transportation infrastructure is expected to become more frequent and severe. (Photo 

by Keith McCall, USDA Natural Resources Conservation Service). (C) Risk for water pollution by sediment, pesticides, and 

nutrients is high in many agricultural areas and is expected to 

increase with climate change. (Map by USDA Natural Resources Conservation Service, Resource Assessment and Strategic 

Planning Division, Map ID:BMW.1731, October 1997).

pollutants out of runoff from agricultural fields, and moderate 

excessively high stream temperatures that threaten aquatic biota 

by providing shade to stream channels (Schoeneberger et al. 

2012, Walthall et al. 2012). Each of these benefits is described 

in more detail in the following sections.

Drought

Agroforestry practices can reduce agricultural demand for 

water during drought. Windbreaks reduce crop water stress and 

conserve soil moisture by reducing windspeed across adjacent 

crop fields, thereby reducing evaporation losses from soil and 

transpiration by crops (Brandle et al. 2009). Silvopastures 

provide wind control and shade for livestock, thereby reducing 

heat stress and water needs (Sharrow et al. 2009). The benefits 

of wind control are described in greater detail in the Commodity Production section in this chapter.

Tree crops are more drought hardy than most herbaceous 

annual crops (Atkinson 2011, Fereres 1984). Drought hardiness 

is attributed to better stress tolerance and to extensive root 

systems that explore more soil for water (Chaves et al. 2002, 

Turner and Kramer 1980,). Agroforestry practices can increase 

soil porosity, reduce runoff, and increase soil cover, leading 

to increased water infiltration and retention in the soil profile, 

which can reduce moisture stress during low rainfall years 

(Anderson et al. 2009, Udawatta and Anderson 2008, Udawatta 

et al. 2002, Verchot et al. 2007). Under certain conditions, trees 

interspersed with crops can make more water available for use 

by adjacent crop plants. Through a process called hydraulic lift, 

deeper rooted trees can redistribute deep soil water supplies 

upward into the crop root zone and sustain crop plants during 

drought (Horton and Hart 1998, Yu et al. 2013). Under less 

extreme conditions, however, trees growing in close proximity 

to crop plants, such as along the edges of windbreaks or in 

closely spaced alleys, will compete with the crop plants for soil 

moisture and limit crop yield (fig. 2.4).

In many northern semiarid areas, such as the northern Great 

Plains, snow is a critical source of soil moisture for crop and 

forage production during the following growing season (Brandle 

et al. 2009). Without windbreaks, much of windblown snow 

is blown off the field and deposited in road ditches and gullies 

or behind fence rows or other obstructions (Greb 1980). Field 

windbreaks can help capture the moisture available in snow 

by slowing the wind and distributing the snow across the field. 

Snow capture and protection of crop plants from winter desiccation 

by windbreaks can increase wheat yields by 15 to 20 percent 

(Brandle et al. 1984, Kort 1988, Lehane and Nielson 1961).

Flooding

Increasing rainfall intensities will produce larger stormflows 

in streams and rivers (Vose et al. 2016). In response, flooding 

A

B

C
Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions 17

will increase and stream channels and banks will experience 

accelerated erosion as waterways adjust to the new flow 

regime. Flooding and stream channel erosion will damage 

crops and nearby transportation infrastructure such as roads, 

railways, and bridges (Kundzewicz et al. 2014, Walthall et al. 

2012, Whitehead et al. 2009, Wilbanks et al. 2012).

Increasing forest cover in watersheds can reduce the total 

amount of runoff and lessen peak stormflows (Vose et al. 

2016). Forest clearing increases total stream discharge and 

peak stormflows (Andréassian 2004, Bosch and Hewlett 1982, 

Mao and Cherkauer 2009, Twine et al. 2004). Reestablishing 

forest cover reverses this trend by a combination of increasing 

rainfall interception and evapotranspiration, increasing rainfall 

infiltration, and retarding the velocity of overland runoff 

flow toward stream channels (Anderson et al. 2009, Bartens 

et al. 2008, Johnson 1998, Kumar et al. 2008, Seobi et al. 

2005, Trimble et al. 1987). This watershed-scale effect can be 

significant, even if trees are reestablished only in narrow strips 

in uplands or in streamside riparian zones (Salemi et al. 2012; 

Smith 1992; Udawatta et al. 2002, 2011b). In arid regions 

such as the desert Southwestern United States, however, 

establishment of streamside forest can reduce critical summer 

base flows because water uptake and transpiration rates by trees 

is greater than by other types of vegetative cover (Scott et al. 

2000, Shafroth et al. 2005, Wilcox et al. 2007).

Forest vegetation on streambanks and floodplains provides 

better protection from the erosive forces of stormflow than do 

annual crops and natural herbaceous cover. Forested banks 

and floodplains experience much lower rates of erosion than 

those that are unforested (Allen et al. 2003; Beeson and Doyle 

1995; Geyer et al. 2000; Hession et al. 2003; Laubel et al. 

2003; Micheli et al. 2004; Thorne 1990; Zaimes et al. 2004, 

2006). Along unstable streams, forest is more effective than 

herbaceous vegetation alone at reducing high bank erosion rates 

(Geyer et al. 2000; Harmel et al. 1999; Simon and Collison 

2002; Zaimes et al. 2004, 2006). Computer models can reveal 

specific sites along stream courses where bank erosion is more 

likely to occur and where establishment of riparian forest 

buffers would be most effective at controlling the erosion 

(Tomer et al. 2003).

Streamside trees can have some negative local effects on 

flooding and erosion. Debris from trees can clog small streams 

and drainage ways, retarding storm drainage and worsening 

farmland flooding. Toppling of large trees can be a localized 

source of accelerated bank erosion (Montgomery 1997, Thorne 

1990). The conversion of herbaceous vegetation on streambanks to forest may cause some limited channel widening 

(Davies-Colley 1997, Lyons et al. 2000, Stott 1997, Sweeney et 

al. 2004, Trimble 1997).

Water Pollution

Nonpoint source water pollution by eroded sediments, fertilizers, and other agricultural chemicals contributes substantially 

to the impairment of U.S. waters (EPA 2013). Increasing 

rainfall intensities under climate change will produce even 

greater amounts of runoff, leading to accelerated soil erosion 

and chemical transport from agricultural fields and also from 

streambanks and channels (Walthall et al. 2012).

Establishing permanent vegetation in and around annually 

cultivated crop fields can reduce the amount of runoff and 

associated erosion from the fields (Dosskey 2001; Reeder and 

Westerman 2006; Renard et al. 1997; Udawatta et al. 2002, 

2011b) and function to filter sediments and chemicals from 

runoff before they reach waterways (Baker et al. 2006; Dosskey 

2001, 2010; Helmers et al. 2008; Lin et al. 2011; Lowrance et 

al. 1997; Mayer et al. 2007). The impact of permanent vegetation, such as in agroforestry practices, on pollutant runoff can 

be substantial. For example, nitrogen removal by a riparian 

forest buffer (fig. 2.9) can be as high as 90 percent or more of 

the runoff load from an adjacent crop field (Anderson et al. 

2014, Dosskey 2001, Lowrance et al. 1997, Mayer et al. 2007). 

Similar levels of sediment removal are also possible (Dosskey 

2001). Phosphorus removal will be somewhat less than that 

for sediment (Dosskey 2001, Hoffman et al. 2009, Lowrance 

et al. 1997, Schmitt et al. 1999). The level of impact achieved, 

however, depends strongly on where buffers are planted 

relative to agricultural source areas (Dosskey et al. 2002, 2013; 

Tomer et al. 2003; Walter et al. 2000, 2007). Greater reduction 

will be achieved where permanent cover is interspersed with 

crops (e.g., alley cropping) on more erodible lands and where 

positioned in the path of runoff flow (e.g., riparian forest 

buffer). Technical tools have been developed that can identify 

the most effective sites in cultivated watersheds for pollution 

control using agroforestry practices (e.g., Dosskey et al. 2011, 

2013). Even greater impact can be achieved by converting 

marginal cultivated land to a permanent silvopasture agroforestry system.

Several agricultural practices, however, can lead to underperformance of agroforestry practices for pollution control. 

Agricultural drainage practices, such as building ditches and 

subsurface tile drains, transport pollutants directly from fields 

into streams without the benefit of filtering through riparian 

forest buffers (Dosskey et al. 2002, McClellan et al. 2014). 

Special buffer designs have been developed for these pathways 

and also for redirecting such flows back into a riparian buffer 

system (Schultz et al. 2009). Filtering of large amounts of 

pollutants by riparian buffers, whether sediments or nutrients, 

cannot continue indefinitely without maintenance actions 

because sediment and nutrient accumulation can eventually 

saturate the retention capacity of a buffer (Dillaha et al. 1989, 
18 Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions

Figure 2.9. Riparian forest buffer is an agroforestry practice that protects water quality and aquatic habitat. (A) A generic design for a 

riparian forest buffer was developed in the early 1990s by the USDA Forest Service. (Welsch 1991). This model was later modified 

and adopted as a conservation practice by the USDA Natural Resources Conservation Service. (B) A riparian forest buffer recently 

established among cropland in central Iowa. (Photo by Lynn Betts, USDA Natural Resources Conservation Service). (C) A clear 

stream with healthy brook trout. (Photo by U.S. Fish and Wildlife Service, Southeastern Region).

Dosskey et al. 2010). Maintenance actions include the periodic 

removal of accumulated sediments and the harvest and removal 

of vegetation and its accumulation of nutrients.

Increasing sediment loads under climate change likely will 

produce a compounding negative effect on water supply in 

irrigation-dependent agricultural regions such as the Great 

Plains. More intense rainfall events will accelerate soil erosion 

and subsequent sedimentation in water storage reservoirs and 

more quickly diminish the capacity to supply water during 

intervening drought periods (Kundzewicz et al. 2014, Whitehead et al. 2009, Wilbanks et al. 2012). Longer, hotter drought 

periods will reduce soil cover by crop and pasture vegetation 

and leave the soil increasingly vulnerable to accelerated 

erosion (Walthall et al. 2012) and sedimentation during 

subsequent rainfall events. Permanent vegetative cover in the 

form of drought-hardy agroforestry practices can maintain soil 

A

B C
Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions 19

protection through drought periods and storm events and can 

filter sediments from runoff, thereby maintaining the functional 

lifespans of water supply reservoirs.

Water Temperature

A predicted rise in stream water temperature may be one of 

the more significant effects of climate change on stream biota 

(Mohseni et al. 1999, Rieman et al. 2007, Wenger et al. 2011b, 

Wu et al. 2012). Elevated water temperature threatens the 

sustainability of existing aquatic communities, particularly 

cold-adapted fish species such as salmon and trout (Caissie 

2006; Dunham et al. 2007; Mohseni et al. 2003; Poole and 

Berman 2001; Rieman et al. 2007; Wenger et al. 2011a, 

2011b). Higher water temperature can also spur the growth of 

toxin-producing algal species (Whitehead et al. 2009).

Shade provided by riparian forest buffers can moderate 

increases in stream water temperature. Removal of the streamside forest, which is common in agricultural landscapes, is a 

major stressor of stream health in the United States (EPA 2013, 

Sweeney and Newbold 2014). Unshaded streams, especially 

smaller streams, experience higher summer temperatures than 

those under full shade (Sweeney and Newbold 2014). Streamside forested buffers of at least 30 meters (m) in width may be 

sufficient for providing maximum thermal protection in small 

streams (Sweeney and Newbold 2014). The degree to which a 

rise in water temperature can be moderated, however, will also 

depend on other factors, such as the size of the stream, relative 

contribution of groundwater to total streamflow, other land uses 

in the watershed, and their cumulative effects throughout the 

stream network (Beschta and Taylor 1988, Callahan et al. 2014, 

Groom et al. 2011, Luce et al. 2014, Sweeney and Newbold 

2014). Mathematical modeling has been used to integrate 

effects of multiple factors and to predict stream temperatures 

under future climate scenarios (e.g., Arismendi et al. 2014, 

Daraio and Bales 2013, Luce et al. 2014).

Most water resource benefits of agroforestry have a lag time 

between installation and impact. Functions such as providing 

shade, wind protection, restoring soil permeability, and developing surface debris will accrue slowly as trees grow (Dosskey 

et al. 2010). As a consequence, many benefits to water supply 

and to pollution, flood, and temperature control likewise will 

accrue slowly. Furthermore, benefits to streamflow, pollution 

control, and temperature accrue at the watershed scale so that 

their level of benefit will depend largely on the extent of land 

coverage by appropriately designed agroforestry practices.

Key Findings

Implementation of agroforestry practices on otherwise cultivated annual cropland and herbaceous pastures can offset threats 

to water resources by—

• Reducing water stress in nearby crops and livestock through 

microclimate (wind, shade) modification.

• Protecting streambanks and engineered infrastructure from 

erosion damage during stormflows.

• Moderating water pollution.

• Moderating high stream temperatures and protecting cold 

water-dependent biota.

Key Information Needs

• Enhanced planning tools to assist managers with optimum 

placement and design of agroforestry practices for effective 

control of erosion and water pollution.

• Documentation of impacts of agroforestry implementation 

on water resources at the watershed scale.

Air Quality

Weather and climate factors such as temperature, humidity, 

and wind influence the emissions, transport, dilution, transformation, and eventual deposition of air pollutants (Kinney 

2008). Changes in these variables due to climate change will 

influence air quality, contributing to potential impacts on public 

health, safety, and quality of life. For instance, more than 20 

million people in the Midwestern United States experience air 

quality that fails to meet national ambient air-quality standards 

(Pryor and Barthelmie 2013). Climate change is expected to 

exacerbate human health problems by increasing air pollution 

(Melillo et al. 2014).

Agricultural operations can be a significant source of air 

pollutants (Aneja et al. 2009). For example, particulate matter 

emitted from agricultural lands in the Columbia Plateau region 

of the Pacific Northwest is a major contributor to poor air 

quality (Sharratt et al. 2007). Other air pollution concerns 

arising from agriculture include odor and ozone. Agroforestry 

may reduce the effects of climate change on ambient air quality 

by buffering and protecting agricultural lands. The capacity for 

these services is described in the following sections for each 

type of air pollutant.

Dust

Particulate matter (PM) emissions from agriculture in the 

United States contribute about 14 percent of PM2.5 emissions 

and approximately 22 percent of PM10 emissions (EPA 2011). 

A significant portion of these emissions consists of dust 

from cropping systems and livestock operations (EPA 2011). 

Airborne dust is a human health concern across many agricultural areas in the United States (Gares et al. 2006, Sharratt et al. 

2007, Stout 2001) (fig. 2.10). Elevated dust in the atmosphere 
20 Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions

Figure 2.10. Blowing dust is a continuing air-quality problem 

in semiarid regions and is likely to worsen with climate change. 

A duststorm engulfs Brownfield, TX, on June 22, 2006, reducing air quality and harming public health. This storm caused 

several traffic accidents, resulting in a fatality and several 

injuries. (Photo by David Drummond). 

can lead to skin and eye irritations, shortness of breath, asthma, 

and other respiratory disorders that contribute to significant 

healthcare costs (Clausnitzer and Singer 2000, Smith and 

Lee 2003, Williams and Young 1999). Poor visibility due to 

windblown dust also contributes to highway accidents and 

traffic fatalities.1 Dust can be transported from regional to 

intercontinental scales, creating problems and hazards well 

beyond the source (Chin et al. 2007).

Predicted hotter, drier summers under climate change will 

likely lead to increased drying of soils, wind erosion, and 

airborne dust (Lee et al. 1996, Zobeck and Van Pelt 2006). 

Under higher greenhouse gas emission scenarios, drought is 

projected to become more common throughout most of the 

Central and Southern United States, contributing to higher 

airborne dust levels due to a reduction in vegetative cover (Lee 

et al. 1996, Melillo et al. 2014). Bioaerosols, such as fungal 

spores and endotoxins, are likely to be more of a problem under 

drier conditions (Boxall et al. 2009). Duststorms associated 

with drought conditions have been associated with increased 

incidence of Coccidioidomycosis (an infection referred to as 

valley fever, which is caused by a soil-borne fungal pathogen) 

in Arizona and California (Comrie 2005). Although the 

capacity of current climate models to predict future windspeeds 

is limited, estimated reduction in windspeeds in some U.S. 

regions due to climate change may offset some of the increased 

wind erosion potential (Breslow and Sailor 2002, Sailor et al. 

2008, Segal et al. 2001).

Windbreaks, through a variety of physical processes, can 

reduce windspeed over the land surface and thereby reduce the 

mobilization and transport of dust and associated particulates 

(Heisler and Dewalle 1988, Tibke 1988). The zone of reduced 

windspeed typically extends a distance equivalent to 10 to 20 

tree heights downwind of a windbreak, so multiple barriers are 

often required to effectively control wind erosion from large 

fields (Tibke 1988). Trees can also filter the air by intercepting 

airborne particles (Hill 1971). Trees have been observed to reduce dustfall by 30 to 42 percent and total suspended particles 

by 11 to 13 percent (Dochinger 1980) (see box 2.1 describing 

agroforestry’s role in mitigating the 1930s Dust Bowl). The 

perennial vegetation used in agroforestry practices can also 

reduce the area of farm soil exposed to erosion (Asbjornsen et 

al. 2014).

Odor

Odor emitted from livestock and poultry production facilities 

can be a significant problem for human health, quality of rural 

life, and local economies (Donham et al. 2007, Palmquist et al. 

1997, Wing and Wolf 2000). Odors from these facilities can be 

offensive and cause eye, nose, and throat irritations; headaches; 

nausea; palpitations; and other symptoms (Heederik et al. 2007, 

Schiffman and Williams 2005, Thu 2002). Odors arise primarily 

from manure decomposition and consist of a complex mixture 

of gaseous and particulate compounds (Bottcher 2001). Depending 

on weather conditions, odorous compounds can be perceived 

by residents more than 5.5 kilometers (km) from their source 

(Guo et al. 2005).

Predicted warmer temperatures will increase the production of 

odorous compounds through faster anaerobic decomposition of 

manure (Miner 1995). Odor transport is also favored by stable 

atmospheric conditions, low windspeed, and high ambient 

temperature (Xing et al. 2007), conditions likely to increase 

under projected climate scenarios (Melillo et al. 2014).

Evidence suggests that windbreaks located adjacent to livestock 

production facilities can help mitigate odors through a mix of 

physical and social dynamics. Trees and shrubs can filter and 

intercept odor-causing particulates and gases, in part, because 

of the large surface area provided by plant foliage (Hill 1971, 

Khan and Abbasi 2000). Windbreaks can lift the odor plume 

into the lower atmosphere, aiding in dilution and dispersion 

(Lin et al. 2006). Land deposition of odorous particulates and 

aerosols can occur downwind of the windbreaks due to reduced 

windspeeds (Laird 1997, Thernelius 1997). Trees may serve 

as a biological sink for the chemical constituents of odor after 

interception (Hill 1971, Tyndall and Colletti 2007). Enhancing 

1

 KOAA Channel 5: January 13, 2014. http://www.koaa.com/news/blowing-dust-causes-multiple-accidents-on-i-25/. Lincoln Journal Star: April 

29, 2014. http://journalstar.com/news/local/dust-storm-chokes-i--traffic-in-panhandle/article_f92ddcd6-b48f-5469-a462-1c5dcab11355.html?comment_form=true. KSAL: April 30, 2014. http://www.ksal.com/drought-wind-causing-big-dust-storms/.
Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions 21

the aesthetics of livestock production sites with vegetation such 

as windbreaks has also been shown to reduce the perception 

of odor (Kreis 1978, Mikesell et al. 2001, Tyndall and Colletti 

2007).

Odor concentrations can be reduced by 6 to 66 percent when 

measured downwind from windbreaks (Hernandez et al. 

2012, Lin et al. 2006, Malone et al. 2006, Parker et al. 2012). 

Although windbreaks can contribute to reducing concentrations 

of odorous compounds, it is recommended that windbreaks be 

viewed as complementary technology to be used with a suite of 

odor management strategies (Tyndall and Colletti 2007).

Ozone

Ground-level ozone causes respiratory problems for humans 

and damages sensitive vegetation, including crops and 

forests. Climate change is expected to increase summertime 

ground-level ozone in polluted regions by 1 to 10 parts per 

billion during the coming decades (Jacob and Winner 2009). 

Nonattainment of ozone air-quality standards is typically an 

issue in urban areas; however, some U.S. agricultural regions, 

such as the San Joaquin Valley in California, also suffer from 

high ozone levels (Yates et al. 2011). Although ozone is not 

emitted directly from agricultural operations, it is formed 

through the chemical reactions of nitrogen oxides (NOx) and 

volatile organic compounds (VOCs) that are considered to be 

ozone precursors. These ozone precursors can be produced 

by agricultural processes such as decomposition of plant and 

animal wastes, combustion engines in farm equipment, burning 

of crop residue, and applications of pesticides and nitrogen 

fertilizer (Yates et al. 2011).

Agroforestry can help reduce ground-level ozone indirectly 

by reducing NOx and VOC emissions. Agricultural pesticide 

applications are a significant source of VOC emissions and 

methods to reduce the number of applications will reduce the 

concentration of VOC emissions (Yates et al. 2011). Biological 

pest control provided by agroforestry practices may reduce 

pesticide applications that contribute to VOC emissions. 

Agroforestry practices can facilitate beneficial insect dispersal 

into fields and predation on pest species, reducing pesticide 

use (Bianchi et al. 2006, Chaplin-Kramer and Kremen 2012, 

Griffiths et al. 2008, Holland and Fahrig 2000, Morandin et 

al. 2014) (see Biodiversity section for additional information). 

Increasing the area occupied by woody vegetation can reduce 

the number of equipment passes, reducing fuel use and 

emissions (Brandle et al. 1992). Vegetation can intercept and 

serve as a sink for VOCs and NOx (Nowak et al. 2000, 2006); 

however, trees can also emit VOCs and may offset some of the 

trapping benefit (Nowak et al. 2000). Selecting tree species that 

are low emitters of VOCs may reduce this effect (Taha 1996). 

The overall net impact of agroforestry on ozone precursors is 

still unknown and requires further investigation.

Key Findings

• Agroforestry practices are an effective means to reduce 

human health impacts from windblown dust and other 

particulate matter.

• Windbreaks can aid in reducing odors from livestock 

production facilities. 

• Agroforestry practices can decrease ozone precursors.

Key Information Needs

• Enhanced tools for locating and designing agroforestry 

practices to improve air quality.

• Better understanding of how to reduce odor using agroforestry practices.

• Documentation of the effectiveness of agroforestry practices 

on mitigating ground-level ozone.

Biodiversity

Biodiversity provides the fundamental building blocks for the 

many goods and services that are derived from agroecosystems 

(Altieri 1999). Declines and changes in biodiversity can have 

direct or indirect impacts on ecosystem function, persistence, 

and services (Cardinale et al. 2012). Many stressors, such as 

habitat loss and degradation, invasive species, overuse, pollution, 

and disease, currently are impacting biodiversity (MEA 2005). 

Climate change is another stressor that will exacerbate many of 

these problems, affecting the services that biodiversity provides 

to society (Staudinger et al. 2012). Climate change likely will 

reduce crop pollination by animals by increasing phenological 

mismatching between pollinators and plants (Kjøhl et al. 2011, 

Polce et al. 2014), compound existing stressors on managed 

honey bee colonies (Reddy et al. 2013), displace native pollinator species by invasion of incompatible alien plants (Staudinger 

et al. 2012), and result in other impacts (Melillo et al. 2014, 

Staudinger et al. 2012). Climate change is expected to accelerate insect resistance to pesticides because of longer growing 

seasons yielding more generations per year (Walthall et al. 

2012). Habitat conditions, both terrestrial and aquatic, will be 

altered by changes in precipitation and temperatures (Staudinger et al. 2012). Species that are unable to shift their geographic 

distributions or have narrow environmental tolerances will be 

at an increased risk of extinction (Mantyka-Pringle et al. 2012, 

Staudinger et al. 2012).

Agroforestry has the capacity to conserve biodiversity while 

promoting agricultural production (Jose 2012) and can be 

used to enhance resilience to climate change (Schoeneberger 

et al. 2012). Agroforestry plays five major roles in conserving 

biodiversity by providing (1) perennial habitat for species in 
22 Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions

otherwise monocultured annual croplands; (2) preservation of 

germplasm for sensitive species; (3) a productive alternative 

to land clearing for monocultured annual crops; (4) corridors 

between habitat remnants needed for conservation of area-sensitive plant and animal species; and (5) erosion control and 

water quality protection, among other services, that prevent 

the degradation and loss of habitat (e.g., Jose 2009, 2012). 

The following sections summarize the important benefits and 

tradeoffs of using agroforestry practices to mitigate some 

climate change impacts on biodiversity.

Pollination

More than 30 percent of food production relies on insect pollination, overwhelmingly provided by both European honey bees 

and wild native bees (Klein et al. 2007). Pollination services 

by managed honey bee colonies are expected to decline under 

predicted climate change scenarios due to impacts on their 

biology, behavior, and distribution (Reddy et al. 2013). Given 

the challenges facing managed honey bee colonies, it is important to diversify the pollinators on which growers rely. Wild 

native bees, which number more than 4,000 species in North 

America, pollinate crops worth at least $3 billion annually 

in the United States (Losey and Vaughan 2006). Conserving 

a diverse assemblage of pollinators, with different traits and 

responses to ambient conditions, is considered one of the best 

ways to minimize risk due to climate change (Kjøhl et al. 2011, 

Rader et al. 2013, Winfree et al. 2007). Native bees and other 

pollinators can benefit from agroforestry in several ways.

When appropriate tree and shrub species are used in agroforestry practices, these woody plants can provide important sources 

of pollen and nectar for pollinators, especially when crops are not in 

flower (Hannon and Sisk 2009, Miñarro and Prida 2013). These 

species can provide flowers of various sizes, shapes, and colors 

that support a diverse community of bees and other pollinators 

(Nicholls and Altieri 2013, Potts et al. 2003, Roulston and 

Goodell 2011). Enhancing plant diversity through agroforestry 

can alleviate the potential spatial and phenological mismatch 

between pollinators and plants by offering a variety of resources to enhance pollinator stability under climate variation (Kjøhl 

et al. 2011, Polce et al. 2014). Providing substantial floral 

resources throughout the growing season is critical to sustaining an adequate population of pollinators that can effectively 

pollinate a crop (Morandin and Kremen 2013, Morandin et al. 

2011). For instance, agroforestry practices incorporating early 

flowering species like willows (Salix spp.) can provide some 

of the first pollen and nectar resources of the season, boosting 

early-season pollinator populations (Ostaff et al. 2015).

Agroforestry practices can provide nesting habitat for native 

bees. Approximately 30 percent of native bees are solitary 

woodnesters that require trees and shrubs for nesting (Cane et 

al. 2007, Grundel et al. 2010, Potts et al. 2005). Some build 

their nests inside hollow tunnels provided by soft, pithy centers 

of branches or tunnels left behind by wood-boring beetle 

larvae; others excavate their own tunnels. About 70 percent 

of native bee species create nests under ground and require 

undisturbed ground such as that under trees and shrubs not 

subject to tillage or soil disturbance (Cane et al. 2007, Potts 

et al. 2005). Bumble bees (Bombus sp.), some of the most 

effective native pollinators, often construct ground-level nests 

at the interface between fields and linear woody habitat such as 

hedgerows and windbreaks (Kells and Goulson 2003, Svensson 

et al. 2000). Bumble bee nest densities can be twice as high 

in these linear woody habitats compared with grassland and 

woodland habitats (Osborne et al. 2008).

Agroforestry practices can offer habitats with favorable microclimate conditions for pollinator activity. The practices can provide 

numerous niches that allow pollinators to find suitable sites 

for thermal regulation (Kjøhl et al. 2011, Pollard and Holland 

2006). Windbreaks and other practices reduce windspeeds in 

fields, minimizing the desiccation of petals and loss of pollen 

viability (Wilcock and Neiland 2002) while also allowing 

pollinators to forage during high wind events that would 

normally reduce or prohibit foraging (Brittain et al. 2013).

Agroforestry practices can provide pollinator habitat close to 

crops. Pollinator visits to a crop drop off dramatically when 

the pollinator habitat is not located nearby (Dramstad 1996, 

Klein et al. 2012, Morandin and Kremen 2013, Morandin et al. 

2014, Ricketts et al. 2008) (fig. 2.11). Fruit set of pollinatordependent crops is estimated to decrease by 16 percent at 1 km 

distance from the nearest pollinator habitat (Garibaldi et al. 

2011). Reducing the distance between pollinator habitat at the 

field and landscape scales can result in greater pollination and 

yield production (Benjamin et al. 2014, Holzschuh et al. 2012). 

Figure 2.11. The effectiveness of pollination declines with 

increasing distance that pollinators must travel from their 

natural habitat. Agroforestry practices such as hedgerows and 

windbreaks can provide the critical habitat at field margins that 

native pollinators require. (Data from Ricketts et al. 2008).
Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions 23

Pollinators, particularly bumble bees, use linear habitat features 

to travel from field to field, increasing pollination activity and seed 

set (Cranmer et al. 2012, Van Geert et al. 2010). Agroforestry 

practices can provide pollinator habitat and travel corridors at 

these spatial scales while simultaneously offering other services, 

such as microclimate benefits, to crops and soil protection.

Bees can be negatively affected by exposure to many agricultural pesticides, ranging from direct contact to inadvertent 

spray drift (Arena and Sgolastra 2014). Agricultural spray 

drift is predicted to rise due to increased pesticide volatility 

under predicted warmer temperatures (Bloomfield et al. 2006). 

Windbreaks, hedgerows, riparian forest buffers, and alley 

cropping can reduce pesticide spray drift from coming onto or 

leaving a farm. Branches, leaves, and stems of woody plants 

can capture pesticide particles, and the windspeed reduction at 

the application site can reduce movement of pesticides off their 

target (Kjær et al. 2014, Lazzaro et al. 2008, Otto et al. 2009, 

Richardson et al. 2004). Spray drift reductions of 80 to 90 

percent can be achieved with woody buffers; however, because 

data gaps for using this method accurately still exist and buffer 

vegetation can be harmed by pesticides, plant species selection 

is critical (Ucar and Hall 2001). Agroforestry practices can 

also serve as safe havens for pollinators if adequately protected 

from spray drift (Davis and Williams 1990, Lazzaro et al. 2008, 

Longley et al. 1997).

Biological Pest Control

Insect pests are responsible for 18 percent of the loss in crop 

production globally (Oerke 2006), and this loss is expected 

to increase under a warmer climate (Walthall et al. 2012). 

Beneficial insects, such as arthropod predators and parasitoids, 

suppress populations of insect pests in agricultural crops, 

an ecosystem service that has been estimated at $4.5 billion 

annually in the United States (Losey and Vaughan 2006). 

Supporting biological pest control through agroecosystem 

diversification may be a strategy for suppressing pest outbreaks 

under a changing climate (Lin 2011). Diversification at the 

farm and landscape level has been shown to increase beneficial 

insect abundance and diversity in crops, although the overall 

impact on pest control is less well documented (Chaplin-Kramer and Kremen 2012, Chaplin-Kramer et al. 2011, Shackelford 

et al. 2013). Increasing habitat diversity with agroforestry 

practices can support biological pest control in several ways.

Agroforestry practices can provide a food supply for beneficial 

insects when crop pests are not available (Gareau et al. 2013, 

Morandin et al. 2011, Stamps and Linit 1998). In annual 

cropping systems, beneficial insects lack continuous sources of 

alternative prey. Agroforestry practices also offer stable habitat 

that benefits reproduction, overwintering, and refuge from 

perturbations of farming practices (Pywell et al. 2005, Varchola 

and Dunn 2001).

Agroforestry practices within fields (e.g., alley cropping) or 

adjacent to fields (e.g., windbreaks, hedgerows, riparian forest 

buffers) facilitate beneficial insect dispersal into fields (Bianchi 

et al. 2006, Chaplin-Kramer and Kremen 2012, Griffiths et al. 

2008, Holland and Fahrig 2000). Pest control from parasitism 

has been found to extend 100 m from hedgerows (Morandin 

et al. 2014). Reducing wind in fields can also significantly aid 

beneficial insects in finding and consuming pests. Wind barriers 

can improve crop pest reduction by beneficial insects by up to 

40 percent (Barton 2014). In some cases, however, trees and 

shrubs may inhibit movement of certain beneficial insects, 

potentially limiting their effectiveness for controlling crop pests 

(Mauremooto et al. 1995).

Birds also use the woody habitat in agroforestry practices 

and can contribute to pest control, although the impact of this 

service is still unquantified (Kirk et al. 1996, Puckett et al. 

2009, Tremblay et al. 2001). Bats may also provide pest control 

(Boyles et al. 2011), but this service has been explored primarily in tropical regions (Maas et al. 2013). The role of birds and 

bats in controlling pests warrants further investigation.

In some cases, agroforestry practices may exacerbate pest 

problems by protecting insect pests, allowing them to maintain 

and rebuild populations to reinvade crop areas (Slosser et al. 

1984). Certain plant species might also provide a host for crop 

pests. For example, European buckthorn (Rhamnus cathartica), 

a species historically used in agroforestry plantings, has proven 

to be invasive and an overwintering host for the Asian soybean 

aphid (Aphis glycines) (Heimpel et al. 2010). Choosing the 

right practice for a particular location and carefully selecting 

and managing plants will be critical to minimize potential 

problems (Griffiths et al. 2008).

Corridors

Climate change is intensifying the negative cumulative effects 

of habitat loss and fragmentation on biodiversity (Staudinger 

et al. 2012). Habitat fragmentation will likely impede the 

ability of many species to respond, move, and/or adapt to 

climate-related impacts (Mantyka-Pringle et al. 2012). Enhancing connectivity between remaining habitat fragments across 

landscapes may reduce population fluctuations and extinction 

risk and promote gene flow and adaptation (Heller and Zavaleta 

2009, Mawdsley et al. 2009). Connectivity can be enhanced by 

establishing corridors and stepping-stone reserves or by taking 

management actions that enhance landscape permeability 

(Krosby et al. 2010). Although corridor benefits are species 

dependent, corridors are most likely to benefit species with 

slow-growing populations that have low survivorship when 

dispersed through fragmented landscapes (Hudgens and 

Haddad 2003).
24 Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions

Agroforestry practices such as windbreaks, hedgerows, and 

riparian forest buffers can function as forest corridors in the 

agricultural landscape (e.g., Haas 1995, Hilty and Merenlender 

2004). Corridors can be effective for species movement although 

evidence for supporting population viability is currently limited 

(Davies and Pullin 2007, Gilbert-Norton et al. 2010). Minimal 

migrations (i.e., one individual per generation) between habitat 

patches, however, may minimize loss of genetic diversity (Mills 

and Allendorf 1996). For example, in the intensely farmed 

Tensas River Basin, threatened Louisiana black bears (Ursus 

americanus luteolus) use riparian forest buffers to travel between 

forest patches to forage and breed (Anderson 1997) (fig. 2.12). 

Agroforestry practices like alley cropping, silvopasture, and 

forest farming also create landscape structure similar to natural 

forest and increase permeability of agricultural landscapes to 

animal movement and population persistence (Eycott et al. 

2012, Watling et al. 2011). In some regions, however, forest 

corridors and habitats may be detrimental to grassland species 

(Pierce et al. 2001).

Farmers often view corridors and other noncropped habitat 

as a reservoir for problem species, such as weeds, that can 

invade their fields—a perception that may increase due to the 

prediction that weed populations will increase under climate 

change (Walthall et al. 2012). Corridors can provide habitat for 

weed species and may function as invasion conduits, but they 

are not a major source of weeds in agricultural fields (Boutin et 

al. 2001, Devlaeminck et al. 2005, Reberg-Horton et al. 2011, 

Wilkerson 2014). Through management such as mowing and 

maintaining perennial vegetative cover, potential weed issues 

can be minimized and, in some cases, corridors may serve as 

barriers to weed invasion (Boutin et al. 2001, Wilkerson 2014). 

Some have expressed concern that providing wildlife corridors 

such as riparian forest buffers and hedgerows in the vicinity 

of fruit and vegetation fields can increase food safety risks if 

wildlife is a disease vector for pathogens such as Escherichia 

coli O157:H7 (Beretti and Stuart 2008). Current evidence, 

however, suggests wildlife is not a significant source of foodborne pathogens and that wildlife habitat adjacent to fields does 

not increase food safety risks (Ferens and Hovde 2011, Ilic et 

al. 2012, Karp et al. 2015, Langholz and Jay-Russell 2013).

Key Findings

• Agroforestry practices can support crop pollination and 

biological pest control by providing the habitat needs of 

native pollinators and beneficial insects.

• Pollinators, beneficial insects, and other flora and fauna 

species can be protected from pesticide applications through 

the use of agroforestry practices.

• Habitat connectivity may be augmented with agroforestry 

practices, potentially enabling flora and fauna species to 

adapt to climate change.

Figure 2.12. The Louisiana black bear was once abundant in East Texas, southern Mississippi, and all of Louisiana. Forest clearing for agricultural and urban development diminished the bear’s habitat by 90 to 95 percent, leading the U.S. Fish and Wildlife 

Service to designate the bear as threatened in 1992 under the Endangered Species Act. Wildlife biologists studying the bears in 

the Tensas River Basin in northern Louisiana determined that wooded corridors along rivers and ditches enable the bears to move 

between isolated patches of favorable forest habitat and have played an important role in sustaining the species in a landscape 

dominated by corn, soybeans, and cotton. (Source and photos from USDA Natural Resources Conservation Service 2004).
Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions 25

Key Information Needs

• Better understanding of how agroforestry practices can 

support biological pest control by bats, birds, and other 

natural enemies. 

• Improved models for designing agroforestry practices to 

mitigate pesticide impacts on flora and fauna species.

• Documentation of the effect of corridors on crop pests (i.e., 

weeds, insects, and diseases) and on beneficial flora and 

fauna populations under climate change.

• Increased capacity to manage agroforestry practices at 

landscape scales for enhancing pollination and biological 

pest control.

Adaptable Plantings

To be an effective adaptation strategy, agroforestry plant materials must themselves be adaptable to climate change effects. 

Changing climatic conditions will impact plant survival and 

function, which, in turn, determines agroforestry’s utility as an 

adaptation and mitigation option. Tree and shrub species have 

multiple points of climate vulnerability: winter chilling requirements, springtime freeze risk, heat and water stress, pollination 

constraints, and disease and pest damage (Winkler et al. 2013). 

Winter warming trends predicted for many regions of the 

United States (Melillo et al. 2014) may reduce chilling hours, 

which, along with changes in frost, drought, and heat events, 

will influence quality and yield from many fruit/nut-producing 

species (Winkler et al. 2013). Disease and pest dynamics are 

expected to shift and escalate, which, when combined with 

abiotic tree stress, will further impact performance and survival 

of many woody species (Ayres and Lombardero 2000).

The selection of plant materials will need to take into account 

changing climatic conditions altering the geographical distribution of plants (Iverson et al. 2008a, McKenny et al. 2007b). 

Geographic ranges where species naturally reproduce, survive, 

and grow will shift as thresholds of tolerance are exceeded 

in some current locations and new locations come to within 

tolerable thresholds. Planted crops and agroforestry tree species 

will experience a similar effect—perhaps even more so as 

many agroforestry species are introduced and not necessarily 

locally well adapted. Given that woody plant material is long 

lived, the success of an agroforestry practice will depend on the 

adaptability of the planted trees and shrubs to both current and 

future climate regimes (fig. 2.13). Several tools are available 

for identifying agroforestry species that are adaptable in 

specific regions.

Through informed decisions on plant selection, agroforestry 

may offer a way to facilitate assisted migration of plant species 

(Dawson et al. 2011). For temperate forest species, it has been 

Figure 2.13. Successful agroforestry must include trees that 

are adapted to both present and future climatic conditions. 

Tree death will compromise the long-term effectiveness of this 

windbreak in Nebraska. Windbreak renovation, in which maladaptive trees are replaced over time, will be key in maintaining 

healthy and functioning plant materials. (Photo by Nebraska 

Forest Service).

estimated that migration rates of more than 1 km per year may 

be needed for tree species to keep pace with current temperature 

and precipitation changes, a speed of migration tenfold greater 

than that observed in the past under natural climate change for 

key taxa (McLachlan et al. 2005, Pearson 2006, Petit et al. 2008). 

Assisted migration is an approach to lessen climate change 

impacts by intentionally moving species to more climatically 

suitable locations (Pedlar et al. 2012, Williams and Dumroese 

2013). This approach can carry potential risks, such as the 

creation of invasive species, hybridization with new species, 

and the introduction of disease to other species; therefore, 

strategies to minimize risks need to be considered (Pedlar et 

al. 2012). Species-selection frameworks and other tools are 

available to support decisionmaking with considerations for 

assisted migration (Williams and Dumroese 2013).

Model Prediction

Significant changes to plant distribution patterns are expected 

to occur during the next century in response to climate change. 

The 2007 Intergovernmental Panel on Climate Change (IPCC) 

predicted a mean global temperature rise of 2.4 to 6.4 °C by 

the end of the 21st century (IPCC 2007), an increase that has 

been estimated to place 20 to 30 percent of species at high risk 

of extinction (McKenney et al. 2007b, Warren et al. 2013). 

Numerous studies during the past decade have tried to predict 

what shifts may occur in distribution patterns and to determine 

what species will be lost from a particular region (Iverson et al. 

2008b, van Zooneveld et al. 2009, Warren et al. 2013). Studies 

of native North American trees predict the future natural 

habitats for 134 species in the Eastern United States (Iverson 

et al. 2008a). Unlike natural forest lands, cultivated urban and 

agroforestry trees are intentionally planted and may consist 
26 Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions

of native and nonnative species. Useful lifespans of 50 years 

or more may be expected. Therefore, trees planted today may 

be coping with the altered climatic conditions predicted in the 

decades to come.

Many studies have used Climate Envelope Models (CEMs) 

to predict plant species distributions as influenced by climate 

change. CEMs represent a refinement of the traditional USDA 

Plant Hardiness Zone maps (USDA 2012) and can project 

distribution impacts of climate change (McKenney et al. 

2007a). For example, based on climate scenarios developed 

by the IPCC in 2000, the Chicago Botanic Garden recently determined that many commonly planted species would become 

less suitable for climatic conditions that are predicted in future 

decades and that other species would become more suitable 

(Bell 2014). Although critics have raised concerns about the 

CEM technique, other studies have validated the results of 

some case studies using CEMs (Hijmans and Grahman 2006).

Plant Evaluation Trials

Climate extremes typically limit the suitability of cultivated 

tree species for certain regions (McKenney et al. 2007a). Plant 

evaluation trials are used to test the suitability of tree species 

and cultivars developed from breeding and selection programs 

(Braun et al. 2010). These evaluations can be informative when 

conducted in locations frequently challenged by extremes that 

are expected in other regions under future climate regimes. For 

example, the continental climate of the Great Plains region is 

known for hot summers, cold winters, and rapid temperature 

fluctuations (Kunkel et al. 2013). Heavy rains interrupt seasonal 

and prolonged droughts. These conditions are expected to be 

accentuated by climate change and extended into adjacent 

regions (Karl et al. 2009, Kunkel et al. 2013). The John C. Pair 

Horticultural Center near Wichita, KS, conducts tree evaluations 

in this harsh climate. A 2-year period (2011 through 2012) 

brought some of the warmest temperatures on record to the 

Wichita area and only 75 percent of average precipitation. 

Under these conditions, not unlike what is predicted in future 

decades, a test of various cultivars of sugar maple (Acer saccharum), elm (Ulmus spp.), and assorted conifers identified some 

species and cultivars that are more tolerant of these conditions 

than others (Pool et al. 2013). In previous trials, one particular 

ecotype of maple native to western Oklahoma, “Caddo” maple, 

proved to be particularly hardy under extreme heat and drought 

conditions (Griffin 2005, Pair 1995). Trials with Caddo maple 

conducted in other regions, however, determined its suitability 

is geographically restricted from higher rainfall and humidity 

climates farther to the east because of susceptibility to disease.

A regional project to evaluate several seed sources of baldcypress (Taxodium distichum) from Texas and Mexico identified 

some genotypes having potentially better cold hardiness 

(Arnold et al. 2012). In addition, some baldcypress genotypes 

performed well during the historic heat and drought of the 

southern Great Plains in 2011 and 2012. Seed collected from 

the southwestern most populations of baldcypress in Central 

Texas are performing well on sites in Oklahoma and Kansas. 

They are cold hardy, heat and drought tolerant, and adapted to 

the high pH soils common in the Great Plains region (Denny et 

al. 2008).

Long-term, multi-State trials can produce locally relevant information regarding the geographic suitability of new cultivars. 

For example, the National Elm Trial is a 15-State effort to 

evaluate Dutch elm disease-resistant elm cultivars across the 

United States (Jacobi 2014). Often, cultivars that perform well 

in one region of the country fail to survive in another.

Conifers continue to be a challenge to grow successfully in parts 

of the agriculturally important Great Plains. Although they often 

serve as windbreaks, protect against soil erosion, and provide 

wildlife habitat, disease and environmental stress take their toll. 

Species that are known for heat and drought tolerance may not 

be sufficiently cold hardy. Transplant survival can also be a 

problem for species and cultivars that do not exhibit rapid root 

growth (Pool et al. 2012).

Evaluation trials and research will need to include efforts focused 

not only on growth and survival, but also on the resilience of 

fruit/nut production to climate change impacts in plant materials. 

The information garnered from evaluations in locations with 

frequent environmental challenges provides insight into various 

species’ long-term utility in agroforestry and urban landscapes.

Seed Sourcing

Populations of trees and other plants can become adapted to 

local environmental conditions (Aitken et al. 2008, Hufford 

and Mazer 2003, Langlet 1971, Leimu and Fischer 2008, 

Linhart and Grant 1996). Some of these conditions are directly 

influenced by climate change; for example, water availability 

(Dudley 1996a, 1996b; Fenster 1997), winter temperature and 

length (Balduman et al. 1999), competitive regime (Leger 

2008), and pests and pathogens (Thrall et al. 2002). On this 

basis, locally sourced seed is assumed to outperform nonlocal 

seed for restoration, revegetation, and forestry projects, 

especially over the longer term. The benefit of local seed, 

however, is predicated on an environment that is relatively 

constant, which, in this era of rapid climate change, will not 

be the case (Havens et al. 2015). Successful tree planting must 

balance adaptation to current and future climate conditions 

(Bower and Aitken 2008). Selection of plant materials for 

agroforestry can hopefully benefit from lessons learned and 

materials identified in ongoing, broad-based assisted migration 

studies for forests (Williams and Dumroese 2013) as well as 

that from the horticultural and landscaping sectors.
Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions 27

One strategy to account for climate change is to use seed from 

a different location where current conditions are similar to 

those expected locally under climate change. Seed transfer 

zones, within which seed can be transferred with little risk of 

maladaptation, have been developed for several tree species 

(Johnson et al. 2004, Kramer and Havens 2009). They can be 

derived experimentally through plant evaluation trials or more 

quickly estimated using combinations of mapped minimum 

winter temperature zones, aridity, and ecoregions (Bower et 

al. 2014, Erickson et al. 2004, Johnson et al. 2010, Omernik 

1987). The estimation approach has been modified to account 

for climate change, such as warmer temperatures (Kramer 

and Havens 2009, Vitt et al. 2010, Ying and Yanchuk 2006), 

but this approach, like plant evaluation trials, likely will yield 

only approximate results because of uncertainty in both the 

prediction of future local climate conditions and the ability 

to find those conditions currently at a different location. Seed 

transfer zones that account for climate change have been under 

development for economically important tree species for more 

than two decades (Billington and Pelham 1991, O’Brien et al. 

2007, Potter and Hargrove 2012, Rehfeldt 2004, Rehfeldt et al. 

1999, Ying and Yanchuk 2006). These strategies might also 

be useful for identifying multiple species that have developed 

mutualisms through co-evolution and are suitable for transferring as a group (Gallagher et al. 2015).

Agroforestry tree species may be more tolerant and resilient 

than the herbaceous agricultural crops they protect, but they 

are not immune to the adverse impacts of climate change. New 

management practices will need to be developed and, in some 

cases, more resilient germplasm or new species altogether 

will need to be considered. Climate Envelope Modeling, if 

applied correctly, could be a valuable tool for determining 

which species will continue to be suitable for a specific region, 

identifying other regions that may possess hardier germplasm 

for seed sourcing, and identifying potential breeding opportunities that will yield climate change-adapted plant material for 

the future.

Other Adaptation Issues and Strategies

Along with seed source and plant material considerations in 

developing resilient plantings, belowground aspects, especially 

those related to the mycorrhization of plants, need to be 

considered (Compant et al. 2010, Johnson et al. 2013). For 

instance, the ability of southern California oaks to form both 

vesicular-arbuscular and ecto-mycorrhizae provides added 

diversity to help buffer against adverse conditions (Allen 

2015). Not taking into account the belowground conditions, 

like mycorrhizal diversity and suitability, may impair plant 

performance such as found by Kranabetter et al. (2015) in 

their assisted migration studies with Douglas-fir. Management 

activities, ranging from mycorrhizal inoculation to the use of 

tree shelters, application of hydrogels and organic amendments, 

and planting methods, can impact seedling establishment 

success under changing conditions (Piñeiro et al. 2013) and 

therefore provide additional strategies to establish and grow 

more resilient agroforestry plantings.

Given the complexity of factors affecting plant performance 

and persistence, additional research is needed to fully understand 

climate change impacts on agroforestry plant materials (Ayres 

and Lombardero 2000, Luedeling 2012). In the meantime, 

adaptation strategies for agroforestry can be pulled from existing information generated in other sectors, such as horticulture. 

Orchard production research has identified varieties of plant 

materials with lower dormancy requirements and has also 

provided information for in-field management options. One of 

the most effective adaptation strategies is simply increasing the 

plant diversity within a planting, which broadens the mix of 

genetic, phenological, and biophysical attributes (Altieri 1999, 

Lin 2011). Using a wide range of plant materials can reduce 

herbivory by pests (Jactel and Brockerhoff 2007, Aitken et al. 

2008), decrease disease transmission (Lin 2011), minimize 

phenological mismatching between pollinators and plants 

(Polce et al. 2014), and decrease risk from extreme weather 

events (Altieri 1999, Lin 2011). Because agroforestry is a 

designed planting, it offers opportunity for using a variety of 

species and arrangements within a planting. More innovative 

practice designs, such as using resilient woody species to 

provide microclimate benefits to fruit/nut-producing species 

through a mixed-use windbreak or alley cropping system, 

can also offer a way forward while new plant materials and 

management guidance are being developed.

Key Findings

• Agroforestry species currently used in a specific region may 

not tolerate stresses brought on by future climate conditions, 

thus jeopardizing long-term benefits of these practices.

• Successful agroforestry practices may require the introduction of new species and/or cultivars that are better adapted to 

both current and future climatic conditions.

• Models, field evaluation trials, and seed sourcing will likely 

be required to develop suitable species and cultivars.

Key Information Needs

• Better understanding of the impact of future climate 

conditions and interrelated stressors on agroforestry species.

• Improved modeling for predicting species suitability under 

future climatic regimes.

• Refined plant species options for agroforestry practices in 

different regions of the United States under climate change.
28 Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions

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Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions 43

Chapter 3

Greenhouse Gas Mitigation and Accounting

Michele Schoeneberger and Grant Domke

Michele Schoeneberger is research program lead and soil scientist (retired), U.S. Department of Agriculture (USDA), Forest Service, USDA National Agroforestry Center; Grant Domke is team leader and 

research forester, USDA Forest Service, Forest Inventory and Analysis.

Contributors: P.K.R. Nair, Marlen Eve, Alan Franzluebbers, Christopher Woodall, Toral Patel-Weynand, James Brandle, and William Ballesteros Possu

P.K.Ramachandran Nair is the distinguished professor of agroforestry at the School of Forest Resources 

and Conservation, University of Florida; Marlen Eve is the national program leader for Natural Resources 

and Sustainable Agricultural Systems, USDA Agricultural Research Service; Alan Franzluebbers is a 

research plant physiologist, USDA Agricultural Research Service; Christopher Woodall is project leader 

and research forester, USDA Forest Service, Northern Research Station, Center for Research on Ecosystem 

Change; Toral Patel-Weynand is the director of Sustainable Forest Management Research, USDA Forest 

Service, Research and Development; James Brandle is emeritus shelterbelt professor, School of Natural 

Resources, University of Nebraska; William Ballesteros Possu is associate professor, agrarian sciences 

faculty, University of Nariño.

It is well documented that forests provide significant carbon 

(C) sequestration (McKinley et al. 2011). In the 2013 U.S. 

Department of Agriculture (USDA) Greenhouse Gas Inventory, 

forests, urban trees, and harvested wood accounted for the 

majority of agricultural and forest sinks of carbon dioxide 

(CO2) (USDA-OCE 2016). Trees outside of forests (TOF; 

assemblages of trees not meeting the definition of forest based 

on area, width, and/or canopy coverage criteria) also play an 

important role in C sequestration as well as in the reduction of 

greenhouse emissions but do so within agricultural and urban 

lands. While the positive contributions of these forest-derived 

mitigation services within U.S. agricultural lands have been 

documented, the lack of inventory- and activity-specific 

data limits our ability to assess the amount and therefore 

significance of these contributions (Robertson and Mason 2016, 

Schoeneberger 2009). Recent international studies, however, 

indicate these contributions can be very significant in regards 

to overall global and national C budgets (Schnell et al. 2015, 

Zomer et al. 2016).

According to the most recent U.S. Agriculture and Forestry 

Greenhouse Gas Inventory (1990–2013), agriculture in the 

United States contributed 595 million metric tons of CO2 equivalents 

in 2013, with nearly one-half (45 percent) of these emissions 

coming from soils, 28 percent from livestock production (enteric fermentation), and the rest from energy use and managed 

livestock waste (USDA-OCE 2016). Agriculture also has the 

ability to offset these emissions through the use of management 

practices, of which TOF-based practices and, specifically, the 

TOF practice of agroforestry, are now included (CAST 2011, 

Denef et al. 2011, Eagle and Olander 2012, Eve et al. 2014). 

Agroforestry is the intentional integration of woody plants 

into crop and livestock production systems to purposely create 

a number of forest-derived services that support agricultural 

operations and lands, including those services that can directly 

address greenhouse gas (GHG) mitigation and adaptation needs 

related to food security and natural resource protection under 

changing conditions (see chapter 2 in this assessment, Nair 

2012a, Plieninger 2011, Schoeneberger et al. 2012, Verchot et al. 

2007, Vira et al. 2015). It is because of this capacity to simultaneously provide C sequestration and other GHG mitigation 

services, along with adaptation, that interest is growing in the 

use of agroforestry and other TOF systems (e.g., woody draws, 

woodlots, fencelines) in U.S. agricultural climate change strategies 

(CAST 2011, Ogle et al. 2014). The discussions and relevance 

of GHG mitigation accounting methodologies and research 

needs presented in this chapter therefore have significance 

beyond just agroforestry and beyond just U.S. boundaries.

The GHG mitigation capacity of agroforestry will be influenced 

by how the trees, crops, livestock components, or a combination 

of the three are assembled into the many different agroforestry 

practices. The five main categories of agroforestry practices 
44 Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions

used in the United States are (1) riparian forest buffers, 

(2) windbreaks (including shelterbelts), (3) alley cropping 

(tree-based intercropping), (4) silvopasture, and (5) forest 

farming (multistory cropping), with a sixth category capturing 

adaptation of agroforestry technologies to address emerging 

issues such as biofeedstock production and stormwater 

management. A brief description of each agroforestry practice 

is provided in table 1.1 in chapter 1, along with a list of many 

potential benefits these practices may confer to the land and 

the landowner. Additional details on each of these practices 

and their potential benefits are available at the USDA National 

Agroforestry Center Web site (http://nac.unl.edu).

Approaches for assessing the GHG contributions at both entity 

(individual field or farm) and national scales are presented 

in this chapter. Relatively well defined and appropriate for 

forest and cropping/grazing systems, these approaches meet 

current Intergovernmental Panel on Climate Change (IPCC) 

Guidelines for National Greenhouse Gas Inventories (IPCC 

2006) and provide a solid basis for constructing the consistent 

accounting methodologies across spatial scales needed in the 

more variable agroforestry systems. Although information 

is limited, agroforestry’s other direct and indirect effects on 

GHG emissions (nitrous oxide [N2

O], methane [CH4], and 

avoided emissions) are presented to inform future research and 

assessment activities required to build a more comprehensive 

understanding of agroforestry’s contributions to agriculture’s 

net GHG footprint and therefore how these practices can best 

be used within GHG mitigation strategies.

Potential Greenhouse Gas Mitigation 

Roles of Agroforestry

Temperate agroforestry is recognized as a viable land-management option for mitigating GHG emissions in the United 

States and Canada (CAST 2011, Eve et al. 2014, Nair et al. 

2010, Schoeneberger et al. 2012). Agroforestry contributes 

to agricultural GHG mitigation activities by (1) sequestering 

carbon (C) in terrestrial biomass and soils, (2) reducing GHG 

emissions, and (3) avoiding emissions through reduced fossil 

fuel and energy usage. These GHG mitigation benefits are 

derived via the diversity of ecological functions created by and 

management activities used within agroforestry operations, 

both of which translate into greater C capture and tighter 

nutrient cycling in agroforestry compared with conventional 

operations under comparable conditions (Olson et al. 2000).

As a GHG mitigation tool, agroforestry can also provide 

additional ecosystem services and goods that producers and 

society value (see table 1.2 in chapter 1), including adaptive 

capacity for building added resiliency of operations and lands 

to changing climate (see chapter 2 of this assessment, ICF 

2013, Nair et al. 2009, Plieninger 2011, Schoeneberger et al. 

2012). As practiced in the temperate United States (with most 

practices, especially windbreaks and riparian forest buffers, 

comprising less than 5 percent of the field area), agroforestry 

can deliver these services while leaving the bulk of land in agricultural production. A large agricultural land base within the United 

States that could benefit from agroforestry includes nearly 

22 percent of the cropland currently classified as marginal 

(ICF 2013). Even if only a small percentage of this area were 

converted, the potential C sequestration, along with other GHG 

reductions, could become noteworthy. When appropriately located, designed, and managed, agroforestry should not result in 

the conversion of additional lands into agricultural operations 

to replace these generally small portions of land now occupied 

in trees (see chapter 2 of this assessment, Schoeneberger 

2009). For example, the 3 to 5 percent of a crop field put into a 

windbreak should result in increased yield (into the field up to 

a distance of 15 times the height of the trees), providing equal 

to greater returns from putting that small amount into trees (see 

the Commodity Production section in chapter 2).

Carbon Sequestration

Agroforestry’s potential for sequestering large amounts of 

C is well recognized in both tropical and temperate regions 

(IPCC 2000, Kumar and Nair 2011, Plieninger 2011, Udawatta 

and Jose 2012). For example, 13-year-old poplar and spruce 

alley cropping systems in Canada had approximately 41 and 

11 percent more total C, respectively, than accounted for in 

adjacent sole-cropping systems (Peichl et al. 2006). Positive 

trends in C sequestration have been documented in temperate 

regions, and the number of these studies is growing (see Kumar 

and Nair 2011). Tree-based agricultural practices tend to 

store more C in the woody biomass and soil compared with 

their treeless/more conventional agricultural alternatives 

under comparable conditions (table 3.1) (Lewandrowski et al. 

2004, Nair 2012a). Similar to that observed in afforestation 

and reforestation activities (Gorte 2009), this C potential per 

unit area in agroforestry systems can be substantial, largely 

because of the amount of C sequestered in the woody biomass, 

with stem wood accounting for up to 90 percent of the new C 

(Hooker and Compton 2003).

Table 3.1. Estimated carbon sequestration rates for four main 

categories of U.S. agricultural land use. 

Practice category

C sequestration rate

(Mg of CO2 eq 

ha-1 year-1)

Afforestation (previously cropland or pasture) 6.7–19.0

Herbaceous riparian or conservation buffers 1.2–2.2

Conservation tillage (reduced to no-till) 0.7–1.7

Grazing management 2.7–11.9

CO2 = carbon dioxide. eq = equivalent. ha = hectare. Mg = megagram.

Source: Data from Lewandrowski et al. (2004).
Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions 45

Based on U.S. land area that would be suitable for and benefit 

from the non-GHG mitigation services provided by agroforestry, 

such as soil- and water-quality protection (see chapter 2), 

estimates of agroforestry’s C sequestration potential range 

from 90 teragrams (Tg) C per year (yr) (soil + biomass based 

at approximately 15 years into establishment) (Nair and Nair 

2003) to 219 Tg C yr-1 (soil + biomass based at variable years 

[20 to 50 years] into establishment and depending on practice) 

(Udawatta and Jose 2012).

The range in estimates that have been reported over the years, 

from Dixon et al. (1994) to Udawatta and Jose (2012), vary 

substantially because of differences in (1) the assumptions used 

regarding C sequestering rates, (2) which pools were included 

in the estimate, (3) presumed project lifespans, and (4) the 

assumptions each study used to determine land area, where that 

land was, and how much of it would support each agroforestry 

practice type. The lack of national agroforestry inventory 

information in the United States limits our ability to estimate 

land area already under agroforestry and, therefore, current 

C sequestration contributions at regional and national scales 

(Perry et al. 2005, 2009; Robertson and Mason 2016). Regardless of the limited information, the data continue to affirm 

that we know enough to assess the direction of agroforestry’s 

impact on C sequestration within an operation; that we know 

these impacts, in general, will be neutral to highly beneficial 

in comparison with more conventional operations; and that we 

know enough to estimate the larger C sinks in these systems 

(see CAST 2011, Kumar and Nair 2011, Schoeneberger 2009).

Because agroforestry is a combination of agricultural and 

forestry activities, the C stocks from which sequestered C is 

estimated should include the various pools from each of these 

activities. The size of these stocks (and sequestered C) will 

vary by agroforestry practice (fig. 3.1). These stocks will also 

vary with age and/or development of the woody component. 

Adding to the complexity of C fluxes within these system are 

the many interactions generated by the agroforestry plantings 

on other C components within the system, as illustrated in 

the windbreak example in figure 3.2. Recent work, such as by 

Wotherspoon et al. (2014), is helping to build a more comprehensive understanding of C fluxes generated by agroforestry—in this case, alley cropping; however, most studies to date 

report on only a portion of these pools. The lack of national 

inventory information (Perry et al. 2005) and the high cost and 

difficulty of collecting measurement information for all these 

pools have led to more pragmatic approaches for C research 

and accounting in agroforestry (Brown 2002, Schoeneberger 

2009) (see discussion in table 3.2).

Carbon accounting within agriculture and forestry needs to 

consider five main pools: (1) live biomass (above ground), 

(2) live biomass (below ground), (3) dead biomass (dead 

Figure 3.1. Continuum of agroforestry practices from agricultural field to forest stand, with relative carbon stocks by ecosystem pool associated with each practice. Note: This figure 

is for illustration purposes only; actual carbon stocks may vary 

widely, depending on the agroforestry prescription.

Figure 3.2. Major carbon sinks and sources that can be 

affected by a field windbreak. (Schoeneberger 2009).

wood), (4) dead biomass (forest floor), and (5) soil organic 

matter (Eve et al. 2014, IPCC 2006). Table 3.2 provides a 

brief overview regarding the feasibility of accurately and 

cost-effectively accounting for these various pools in agroforestry systems. Table 3.3 provides definitions for these pools, 

with references to estimation approaches for agricultural and 

forested systems. Depending on the level of specificity required 

for reporting, these pools may be further delineated, especially 

within forest land use (e.g., dead wood may be divided into 

standing and downed dead biomass; live biomass may be 

divided into live trees and understory biomass).

The majority of new aboveground C in agroforestry plantings 

is predominantly contained in the standing woody biomass, 

as documented in afforestation and reforestation plantings 

(Hooker and Compton 2003, Niu and Duiker 2006, Vesterdal 

et al. 2002). This component is the most readily visible, easily 
46 Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions

measured, and easily verified portion and, therefore, generally 

tends to be the more studied and reported component. Depending on the objectives, measures and/or estimates of belowground 

woody C and/or soil C may or may not be included with the 

agronomic component (Eagle and Olander 2012, Nair et al. 

2010, Udawatta and Jose 2012).

Regarding the woody biomass component, Zhou et al. (2015) 

and Kort and Turnock (1999) demonstrated that use of existing 

allometric models obtained from forest-grown trees generally 

resulted in the underestimation of woody biomass and C in 

agroforestry plantings. Zhou et al. (2011, 2015) found that 

growth differences in specific gravity and architecture (both 

taper and ratio of stem to branch biomass) created in the more 

open canopies of agroforestry practices compared with forests 

contributed to this underestimation.

Less is known regarding C allocation to belowground woody 

biomass in agroforestry plantings. Estimation of this pool 

currently is accomplished pragmatically using forestry-derived 

protocols (Hoover et al. 2014). Ritson and Sochacki’s work 

(2003) found more open-grown trees may have greater root 

biomass compared with close-spaced trees due to increased 

light and/or more root thickening in response to greater 

mechanical stress from wind sway. Taking these findings—for 

aboveground and belowground woody biomass and, therefore, 

C estimates—into account means that the generally neutral to 

very positive amounts of sequestered C reported to date for 

agroforestry practices in temperate regions may not fully reflect 

the whole contribution of this pool but can be considered a 

conservative assessment of agroforestry’s C sequestration 

contribution.

Table 3.2. Accounting considerations for carbon sequestration pools in agroforestry plantings.a

Project

effects

Ecosystem 

component

Contribution 

to reductionb Fluxc Ability to measure or estimated

Live biomass

Above ground Trees ++ L R—Represents largest pool (Hooker and Compton 2003). Biomass equations 

should be modified for agroforestry plantings (Zhou et al. 2015) or regional biomass equations should be derived from forest stand data. The latter are currently 

available for most agroforestry species and will provide conservative (underestimated) values.

Understory + S–M M—Some plantings may potentially have a large shrub component, especially 

by design, so inclusion in accounting should be considered. Work is ongoing in 

the development of biomass estimation models for a few of the key species of 

shrubs used in agroforestry.

Below ground Trees—

coarse roots

++ M R—Allometric equations should be used with root/shoot estimates (e.g., Birdsey 

1992, Cairns et al. 1997). Increased partitioning of biomass/C to roots is observed in open-grown trees (Ritson and Sochacki 2003), so forest approaches 

will give conservative (underestimated) values for this component.

Trees—

fine roots

+ S–M N—Turnover is extremely high, creating high variability and large error. Positive 

impact of this pool will be reflected, if at all, in the soil organic matter over time.

Understory + S–M M—Some plantings have the potential of having a large enough shrub component that inclusion in accounting should be considered. Work is ongoing in 

the development of biomass estimation models for a few of the key species of 

shrubs used in agroforestry.

Dead biomass

Dead wood 

Forest floor

+ S N—In an afforestation activity, like agroforestry, these components do not accumulate to significant levels until late in a practice’s lifespan. Turnover of litter, in 

general, is higher in these more open systems. Variability and difficulty in estimating litter component is extremely high. 

Soil organic matter

Soil—carbon 

from biomass 

turnover

+ S M—This matter can represent a pool that is influenced just under the tree component; variable distance from the tree over time (assuming main input from tree 

litter) or a combination of tree and crop management influences. Variability/error 

very high and with less certainty other than number will be positive in the long 

term. Soil accrual pool significantly smaller than that in woody biomass within row 

type plantings but could become quite significant in the plantings that occupy 

larger areas (i.e., alley cropping and silvopasture).

a

 Takes into account the woody portion of an agroforestry practice and the understory created by it. Does not include agricultural components altered by the integration 

of woody plants. Currently limited ability to account for the interactions between the agricultural and forestry components so are assessed separately. See discussion in 

the later part of this chapter.

b + and ++ = increasing positive net C potentially sequestered. 

c

 S = small, M = medium, and L = large contribution to C sequestered in that pool, with S and M relative to the proportion the aboveground woody biomass comprises.

d R = recommended, M = maybe, and N = not recommended, based on lack of ease and reliability of getting the value and cost of measurement.

Source: Adapted from Schoeneberger (2009).
Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions 47

Table 3.3. Definitions of carbon pools that may exist in agroforestry practices and the data sources. 

Carbon pool Definition Estimation approaches

Agricultural fields Forest stands

Live biomass Live trees: Large woody perennial plants (capable of reaching a height ≥

15 feet) with a d.b.h. or at root collar (if multistemmed woodland species) ≥

1 inch. Includes the C mass in roots (with diameters > 0.08 inches), stems, 

branches, and foliage.

Parton et al. (1987)

Parton et al. (1998)

Zhou (1999)

Zhou et al. (2011)

Zhou et al. (2015)

Smith et al. (2006)

Jenkins et al. (2003)

Woodall et al. (2011)

Hoover et al. (2014) 

Understory: Roots, stems, branches, and foliage of tree seedlings, shrubs, 

herbs, forbs, and grasses.

Smith et al. (2006)

Russell et al. (2014)

Hoover et al. (2014)

Dead wood Standing dead: Dead trees of ≥ 1 inch d.b.h. that have not yet fallen, 

including C mass of coarse roots, stems, and branches, but that do not lean 

more than 45 degrees from vertical, including coarse nonliving roots > 0.08 

inches in diameter.

Smith et al. (2006)

Harmon et al. (2011)

Domke et al. (2011)

Hoover et al. (2014)

Downed dead: Nonliving woody biomass with a diameter ≥ 3 inches at 

transect intersection, lying on the ground. Also includes debris piles (usually 

from past harvesting) and previously standing dead trees that have lost 

enough height or volume or lean > 45 degrees from vertical, so they do not 

qualify as standing dead trees.

Smith et al. (2006)

Hoover et al. (2014)

Litter The litter layers and all fine woody debris with a diameter < 3 inches at transect intersection, lying on the ground above the mineral soil.Smith et al. (2006)

Hoover et al. (2014)

Soil organic matter All organic material in soil to a depth, in general, of 3.3 feet, including the 

fine roots (< 0.08 inches in diameter) of the live and standing dead tree 

pools, but excluding the coarse roots of the pools above.

Del Grosso et al. (2001)

Del Grosso et al. (2011)

Ogle et al. (2003)

Ogle et al. (2010)

Parton et al. (1998)

Smith et al. (2006)

Hoover et al. (2014)

d.b.h. = diameter at breast height. C = carbon.

Sources: Adapted from Eve et al. (2014); IPCC (2006).

Soil C stocks are likely to be altered in agroforestry plantings 

compared with conventional cropping or grazing systems in 

the United States, but the direction and magnitude of change 

will depend on the ecological context of the site and the type 

of agroforestry system implemented (see the Soil Resources 

section in chapter 2). Inherently highly variable, soil C has been 

found to be even more variable in agroforestry systems (e.g., 

Bambrick et al. 2010, Sharrow and Ismail 2004) compared with 

nearby forest-only plantation and treeless operations and may 

well explain the variability of agroforestry findings reported 

thus far. Methodological difficulties, including differences in 

sampling depth and selection of the site to provide comparative 

baselines, further limit discussion to qualitative rather than 

more quantitative comparisons, especially across regions, 

conditions, and different types of agroforestry practices (Nair 

2012b). Results to date from agroforestry and afforestation 

studies in the United States indicate soil C sequestration 

under agroforestry may actually be negligible/undetectable to 

possibly negative for several years after initial establishment 

(Nave et al. 2013, Paul et al. 2003, Peichl et al. 2006, Udawatta 

et al. 2009).

Erosion control in agroforested areas also confounds easy and 

accurate assessments of C sequestration in the soil pool. Many 

agroforestry plantings, particularly windbreaks and riparian 

forest buffers, are purposely designed to intercept soil eroding 

from adjacent sources. These transported soils, either from 

wind erosion (Nuberg 1998, Sudmeyer and Scott 2002) or 

surface runoff (McCarty and Ritchie 2002), tend to be higher 

in C and other nutrients. The patterns of soil parameter data 

(i.e., litter mass, soil pH, and texture) measured by Sauer et 

al. (2007) from under a 35-year-old windbreak in Nebraska 

documented this deposition. Use of stable C isotope analysis 

is one means of separating out that C that is transported in and 

that C sequestered in situ. Hernandez-Ramirez et al. (2011), 

using this method, identified approximately 50 percent of the 

larger soil organic C (SOC) pool found beneath afforested 

areas versus adjacent cropland in Iowa was tree derived (1.73 

kilograms [kg] C square meters [m-2]), with an estimated mean 

residence time of 45 years and an estimated annual accrual rate 

of 10.6 grams C m-2 yr-1. The cotransport of nitrogen (N) with 

eroded materials into the agroforestry planting may also cause 

confounding impacts. Although the addition of N via erosion 

has not been found to increase soil C efflux or deplete soil C 

stocks (Grandy et al. 2013, Janssens et al. 2010, Ramirez et 

al. 2012), it may be impacting soil C stocks in ways not yet 

identified or understood and requires further investigation.

Perhaps more substantial than the estimation of total SOC are 

the findings that these tree-based systems, compared with their 

treeless counterparts, tend to store significantly more C deeper 

in the profile and in the smaller sized fractions, all of which 

contribute a greater stability to this sequestered C (Haile et 

al. 2008, 2010; Howlett et al. 2011). Soils under the woody 
48 Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions

component of hedgerows, windbreaks, and silvopasture were 

found to consistently have greater total SOC and SOC in all 

size fractions when compared with the treeless agricultural 

component (Baah-Acheamfour et al. 2014).

GHG Mitigation of Other GHGs

Understanding agroforestry’s broader role in GHG mitigation 

beyond the C sequestration described previously entails 

knowledge of its impacts on the other major GHGs of concern 

in agriculture, namely N2O and CH4. Research is limited 

regarding the impacts of agroforestry on these two GHGs. 

The tighter nutrient cycling created by the greater spatial 

and temporal diversity in agroforestry plantings (Olson et al. 

2000) would support the premise that agroforestry should have 

neutral to beneficial effects in reducing emissions of these two 

GHGs when compared with conventional treeless practices 

under similar conditions. In addition, how other management 

activities, especially those involving the management of 

fertilizers and grazing, are implemented in the various 

agroforestry practices will also influence the direction and 

magnitude of this mitigation potential (box 3.1). The data and 

means for accurate estimates of these contributions are not 

available yet for building a quantitative understanding. Enough 

is now known, however, to identify the relative magnitude 

and direction of trends and also the mechanisms at play in 

the various agroforestry practices under different settings. 

Such information can assist in establishing improved design 

and management guidance that better optimize agroforestry’s 

beneficial GHG functions.

GHG Mitigation of Nitrous Oxide

The potential to lower N2O emissions in an alley cropping 

system (also referred to as tree-based intercropping system) 

was estimated at 1.2 kg N2O hectare-1 yr-1 (Evers et al. 2010). 

Amadi et al. (2016) found N2O emissions were about 4 times 

lower in shelterbelts, a factor they attributed to the exclusion 

of N fertilization and also possibly due to greater soil aeration 

under shelterbelt trees. Other studies have also documented 

N2O emission reductions in tree plantings into crop and 

pasture lands; e.g., afforestation plantings (Allen et al. 2009), 

windbreaks (Ryszkowski and Kedziora 2007), and riparian 

forest buffers (Kim et al. 2009). Data regarding the magnitude 

of these trends are insufficient to judge the significance of these 

reductions at broader scales at this time (Ogle et al. 2014).

The elimination or reduction of N-fertilizer inputs on that 

portion of land planted to the agroforestry tree component 

will reduce N2

O emissions from that source. This amount can 

be estimated using methodologies described in Ogle et al. 

(2014). Tighter nutrient cycling that is generally observed in 

multistrata/multispecies plantings, such as agroforestry (Olson 

et al. 2000), should also play a role in reducing emissions, both 

on and off site. Observations of N conservation in agroforestry 

plantings as compared with treeless cropping and grazing 

systems have been documented (Allen et al. 2004, Bambo et 

al. 2009, López-Díaz et al. 2011, Nair et al. 2007). This effect 

will be altered depending on the various types and amounts of 

management activities implemented within the agroforestry 

system, as well as by the age of the woody plants (box 3.1).

N2O emissions are influenced by many different factors and 

are highly variable in agricultural soils (Butterbach-Bahl et al. 

2013, Eve et al. 2014). The additional complexity of spatial and 

temporal factors created in agroforestry, such as influence of 

tree development on nutrient cycling, is expected to play a role 

in reducing net N2O emissions through greater soil N uptake; 

however, it will also make it more difficult to quantitatively 

assess. Riparian forest buffers warrant special attention 

regarding N2O emissions. Although naturally occurring 

riparian forests have been identified as being potential N2O 

hotspots—a function of intercepting additional N from runoff 

and having conditions conducive for denitrification (Groffman 

et al. 2000)—riparian forest buffers are those conservation 

plantings purposely designed and used to intercept field runoff, 

especially nitrates (NO3), to protect water quality. Increased 

uptake of NO3 by riparian forest buffer vegetation has the 

potential to reduce the amount of NO3 that would otherwise 

be available for denitrification and subsequent N2O emission 

(Kim et al. 2009, Tufekcioglu et al. 2003). Harvesting of plant 

materials in the riparian forest buffer zones closest to the fields 

would remove N from the site and help maintain more actively 

growing plant materials and therefore nutrient uptake, especially for N. To offset harvesting costs, these plant materials could 

be specifically selected for and then used/sold as a source of 

biofeedstock (Schoeneberger et al. 2008).
Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions 49

Box 3.1. Management activities within agroforestry practices that can potentially alter 

the magnitude and direction of carbon sequestration and other greenhouse gas fluxes. 

Practice Management activities

Windbreaks • Disturbance to soil by site preparation during establishment.

• Deposition of wind- and water-transported sediments, nutrients, and other agricultural 

chemicals into the planting.

• Windbreak renovation (removal and replanting of dead and dying trees over time).

Riparian forest buffers • Disturbance to soil by site preparation during establishment.

• Deposition of wind- and water-transported sediments, nutrients, and other agricultural 

chemicals into the planting.

• Harvesting of herbaceous materials planted in Zone 3 (zone closest to crop/grazing system) 

and of woody materials planted in Zone 2 (middle zone).

Alley cropping • Disturbance to soil by site preparation during establishment.

• Weed control (mechanical or chemical).

• Pruning, thinning, and harvesting of woody material (amount and frequency vary greatly 

depending on short- and long-term objectives of practice).

• Fertilization for alley crop and possibly also occasionally for trees in rows (i.e., fruit/nut trees).

• Pesticides as needed for alley and row crops.

• Tillage in alleys (frequency and intensity).

• Crop species used in alley production.

• Complex harvesting schedules stratified in space and time.

Silvopasture • Disturbance to soil by site preparation during establishment. 

• Weed control (mechanical or chemical).

• Pruning, thinning, and harvesting of woody material (amount and frequency vary greatly 

depending on short- and long-term objectives of practice).

• Harvesting of needles for pine straw.

• Fertilization of forage component.

• Tillage in forage component (frequency and intensity).

• Crop species used in forage component.

• Grazing management (timing, intensity, frequency).

• Complex harvesting schedules stratified in space and time.

Forest farming • Activities will be predominantly alterations of overstory for canopy manipulation and 

modification of understory as required for specific understory crop being grown and from 

harvesting of crops.

Special applications • Special applications are essentially modifications of the above agroforestry practices to 

address issues such as urban stormwater treatment, biofeedstock production, and waste 

treatment and will entail similar activities as listed above but to varying levels and frequencies of applications.

Source: Adapted from Ogle et al. (2014).
50 Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions

GHG Mitigation of Methane

The second most prevalent GHG emitted in the United States 

from human activities, CH4,is 25 times more efficient at trapping 

radiation than CO2 (USDA-OCE 2016). The largest sources of 

CH4 from agricultural activities are from livestock and manure 

management. The major strategies for reducing these emissions 

are therefore focused on altering how livestock and manure 

are managed; however, assessment of CH4 flux in agroforestry 

is important to obtain a full GHG accounting of these systems 

within farm and ranch operations. Agroforestry can potentially 

alter the CH4 emissions, albeit to only a small extent, by influencing microbially mediated soil activities responsible for CH4

oxidation and reduction, with the latter most likely to occur 

at any measurable extent in well-aerated soils under upland 

practices and the former in periodically flooded soils that tend 

to occur in riparian environments. Agroforestry, specifically 

silvopasture, also can potentially influence CH4 emissions but, 

in this case, through management and rotation of livestock.

Research findings for soil-mediated impacts in agroforestry 

systems at this stage are contradictory. Allen et al. (2009) and 

Priano et al. (2014) found CH4

 uptake to be greater in afforested ex-pasture sites than in pasture, suggesting that agroforestry 

that is afforestation-like could potentially influence CH4 uptake 

positively. In a Canadian study, soil CH4 oxidation potential 

under shelterbelts was 3.5 times greater than in cultivated 

soils, which was attributed to the trees creating more favorable 

moisture, soil organic matter, and infiltration conditions for 

CH4 uptake (Amadi et al. 2016). Upland soils in general, 

particularly under forests, are identified as providing a CH4 

sink; however, this function generally is reduced by soil 

disturbance, such as tillage and N-fertilization (Dutaur and 

Verchot 2007, Suwanwaree and Robertson 2005, Topp and 

Pattey 1997). These findings would suggest that agroforestry 

practices, at least in the early years after establishment, may 

have only limited capacity for CH4 oxidation activity. Soils in 

riparian forest buffers generally are found to be a CH4 source 

due to anaerobic conditions created by periodic flooding. CH4

flux in soils under established riparian vegetation in Iowa, 

however, did not differ from adjacent upland crop soils (Kim 

et al. 2010), most likely due to the altered hydrology generally 

encountered in these Midwest agricultural landscapes.

Silvopasture may have the greatest potential among the 

agroforestry practices to reduce CH4 emissions. Livestock are 

the key CH4 producers in silvopasture systems, and silvopasture affords several management opportunities to influence 

this production. Silvopasture introduces a grazing strategy 

of moving cattle in a rotational stocking system and has the 

potential to produce more digestible feed and greater overall 

gain from feed efficiency due to shade-induced microclimate 

changes (Cuartas et al. 2014, Lin et al. 1998, Mitlöhner et al. 

2001) (see the Livestock Production section in chapter 2). 

Little GHG work has been done with all three silvopasture 

components in place (trees, forage, and livestock). Most studies 

have focused predominantly on only the C sequestering and 

nutrient uptake capacity of the tree and forage components in 

this system (e.g., Haile et al. 2010, Nair et al. 2007). Further 

work to integrate the animal component in the GHG modeling 

and accounting of silvopasture should be a priority, given the 

potential implication to reduce CH4

 emissions by improving 

forage quality via tree-based shading.

GHG Mitigation Through Emission Avoidance

Trees planted on agricultural lands and around farmsteads and 

facilities can increase feed efficiency, reduce the area of land 

tilled, and modify microclimate both around buildings—reducing heating/cooling needs—and near roads—reducing snow 

deposition and, therefore, snow removal on roads (Brandle 

et al. 1992, DeWalle and Heisler 1988, Kursten and Burschel 

1993). These activities lead to reduced consumption of fossil 

fuels, chemical inputs that include N-fertilizer, and electricity 

and natural gas usage on farms and ranches, all of which lead 

to a reduction in GHG emissions. These reductions are also 

referred to as avoided emissions. Machinery fuel and oil, 

N, and herbicides, expressed in terms of kg of C equivalent 

(CE), have been estimated at 0.94 kg CE per kg fuel, 1.3 kg 

CE per kg of N-fertilizer, and 6.3 kg CE per kg of herbicide, 

respectively (Lal 2004). As proposed by Lal (2004), inclusion 

of energy use within the net GHG assessment of an operation 

provides a more complete picture for comparing farm and 

ranch management decisions.

Brandle et al. (1992) estimated potential C storage (sequestered carbon dioxide [CO2

]) and conservation (CO2 avoided 

emissions) that might be realized in a United States-wide 

windbreak-planting program. Their findings indicate avoided 

emissions can play a greater role in GHG mitigation in agriculture 

than that realized from direct C sequestration via biomass. These 

estimates were based on broad assumptions and energy-efficiency 

conditions different from today. Further, they did not include a 

complete accounting of other potential contributions to avoided 

emissions (e.g., reduction in feed quantity required because of 

increased feed efficiency from livestock windbreaks). The magnitude of the estimated contributions found by Brandle et al. 

(1992), along with estimates from a more recent study (Possu 

2015) strongly supports additional research in this area.

Emissions and Sequestration Accounting 

Methods

The IPCC (2006) Guidelines for National Greenhouse Gas 

Inventories presents two basic approaches—(1) the stockdifference method and (2) the gain-loss method—to emissions 
Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions 51

accounting and recommends using the method or combination 

of methods that provides the highest levels of certainty, while 

using the available resources as efficiently as possible. With 

the stock-difference method, mean annual net C emissions or 

sequestration for land subject to human activities is estimated 

as the ratio of the difference in C stock estimates at two points 

in time and the number of intervening years. With the gain-loss 

method, which is a process-based approach, annual changes 

in C stocks are estimated by summing the differences between 

the gains (e.g., increase in biomass) and losses (e.g., biomass 

decomposition) in a C pool. In the United States, both approaches 

are used to estimate C stock changes for different land uses, 

depending on the availability of inventory data. When inventory 

data exist (e.g., the national forest inventory from the USDA 

Forest Service Forest Inventory and Analysis [FIA] program), 

the stock-difference method is used. When inventory data 

are sparse, the gain-loss method or a combination of the two 

methods is used. In agroforestry systems, in which data are 

often limited, it is likely a combination of the two accounting 

methods will be used to obtain estimates of C stock changes 

in the woody and crop-related components. COMET-Farm 

(http://cometfarm.nrel.colostate.edu), a USDA Web-based tool 

for assessing GHG and C sequestration within farm and ranch 

operations, currently uses a stock-difference method in its Quick 

Agroforestry tool (for further discussion see box 6.1 in chapter 6 

of this assessment).

Uncertainty

There is a need to develop agroforestry models with less 

uncertainty regarding C stocks and the other GHGs. The factors 

contributing to uncertainty in GHG accounting in agroforestry 

include measurement and sampling error, modeling error, 

and interpretation of the protocols one follows. Lack of data 

at both the entity and national scales is the primary source of 

uncertainty associated with estimates of GHGs in agroforestry 

systems (Nair 2012b). As new data become available, models 

specific to agroforestry systems may be developed that better 

reflect C stocks and stock changes in these environments.

Monte Carlo methods are often recommended for estimating 

the statistical uncertainty associated with GHG estimates (IPCC 

2006). Although the methods may vary based on data availability, simulations generally are run many times (e.g., 1,000 

to 10,000 times) to obtain a probability distribution around 

the GHG estimate of interest that can then be used to estimate 

statistical uncertainty. Part of the GHG research strategy for 

temperate agroforestry will need to take into account input 

requirements for such exercises.

Carbon Accounting at the Entity Level

One of the many potential benefits of agroforestry systems is 

the sequestration of CO2 from the atmosphere in herbaceous 

and woody biomass and the accumulation of C in live and dead 

organic matter (IPCC 2000, Kumar and Nair 2011). Carbon 

accounting in agroforestry systems represents a challenge 

because of its mix of land use and management practices that 

intersect three distinct land-use categories: (1) forest land, 

(2) cropland, and (3) grassland (table 3.4) (EPA 2014). This 

section provides an overview of carbon pools and accounting 

approaches in agroforestry at the entity level (see Hoover et al. 

[2014] and Ogle et al. [2014] for a full description), with an 

emphasis on woody vegetation and associated ecosystem pools. 

The inventory and accounting methods described in this section 

are consistent with national and international protocols.

Table 3.4. Land-use categories used in GHG accounting in the United States that may include agroforestry practices. 

Land-use 

category

Defining 

agency Description

Forest land USDA Forest 

Service (FIA 

program)

Land areas ≥ 36.6 m wide and 0.4 ha in size with ≥ 10 percent cover (or equivalent stocking) by live trees able 

to attain an in situ height of 5 m, including land that formerly had such tree cover and that will be naturally or 

artificially regenerated. Areas between forest and nonforest lands that have ≥ 10 percent cover (or equivalent 

stocking) with live trees and forest areas adjacent to urban and built-up land are also included. Areas such as 

shelterbelt strips of trees ≥ 36.6 m wide or 0.4 ha in size are also classified as forest. 

Cropland USDA Natural 

Resources 

Conservation 

Service 

(NRI program)

Land areas used for the production of agricultural crops for harvest, including both cultivated and noncultivated 

lands. Cultivated cropland includes row crops or close-grown crops and also hay or pasture in rotation with 

cultivated crops. Noncultivated cropland includes continuous hay, perennial crops (e.g., orchards), and horticultural crops. Cropland also includes land with alley cropping and windbreaks, and also lands in temporary fallow 

or enrolled in conservation reserve programs (i.e., set-asides), as long as these areas do not meet the forest land 

criteria.

Grassland USDA Natural 

Resources 

Conservation 

Service 

(NRI program)

Land area composed principally of grasses, grass-like plants (i.e., sedges and rushes), forbs, or shrubs suitable 

for grazing and browsing and includes both pastures and native rangelands. Includes areas where practices 

such as clearing, burning, chaining, and/or chemicals are applied to maintain the grass vegetation; savannas, 

some wetlands, deserts, and tundra; woody plant communities of low forbs and shrubs, such as mesquite, 

chaparral, mountain shrub, and pinyon-juniper, if they do not meet the criteria for forest land; and land managed 

with agroforestry practices such as silvopasture and windbreaks, assuming the stand or woodlot does not meet 

the criteria for forest land.

FIA = Forest Inventory and Analysis. GHG = greenhouse gas. ha = hectare. m = meter. NRI = Natural Resources Inventory. USDA = U.S. Department of Agriculture.
52 Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions

System Boundaries and Scale

The inventory and accounting methods described in this section 

have been modified from strategic level guidelines (IPCC 2006, 

Smith et al. 2006) for use at the entity level.

C fluxes will occur across the system boundary; however, they 

are not typically estimated, with the exception of harvested 

wood products. Given the array of agroforestry practices, 

trees on a property may not fit a particular land-use definition, 

creating complexities in inventory and accounting. Methods 

from multiple land-use categories (i.e., forest land, cropland, 

and grassland) will likely be required—with care taken to avoid 

double counting—to obtain a comprehensive estimate of C 

stocks and stock changes for the entity (see Eve et al. [2014] 

for complete descriptions of accounting techniques for different 

land-use categories).

Unlike annual crops, which are considered by the IPCC (2006) 

and the U.S. Environmental Protection Agency (EPA 2014) to 

be ephemeral with no net emission to the atmosphere (West et 

al. 2011), perennial woody crops have the potential to sequester 

large amounts of C per unit area (Dixon et al. 1994, Kumar 

and Nair 2011, Nair et al. 2010). To account for C stocks and 

stock changes in agroforestry systems, measurements collected 

as part of a field inventory may be used to meet the necessary 

data requirements for C accounting purposes. In most cases, 

repeated annual measurements are not practical, nor are the 

changes in C stocks sufficiently different from year to year to 

support such remeasurements. Instead, models and/or lookup 

tables from the IPCC (2006) and Eve et al. (2014) may be needed 

to account for temporal changes in vegetation and associated 

ecosystem pools when longitudinal datasets are not available.

Summary of Inventory and Data Requirements

Inventories of natural resources contribute to the accounting 

of various products and/or services (e.g., C sequestration) 

those resources provide. In agroforestry systems, C pools may 

be broadly or narrowly defined, depending on the size of the 

entity and type of management practice. Systems (e.g., forest 

farming) that resemble forest stands may include all ecosystem 

pools typically associated with forest land, but practices in 

which trees are a minor component (e.g., alley cropping and 

windbreaks) may include only certain ecosystem pools common in forest stands (fig. 3.1). The type of agroforestry system 

will dictate which accounting methods are used to obtain C 

stock and stock-change estimates and the inventory information 

necessary to compile those estimates (Eve et al. 2014).

Estimation of C Pools

Obtaining sound estimates of C stocks and stock changes in 

agroforestry systems requires balancing data availability with 

the entity’s resources and needs. Explicitly establishing system 

boundaries and the C in ecosystem pools to be included in 

the accounting framework will help identify possible gaps 

or overlaps between pools or methods, particularly when 

combining methods across land-use categories. Furthermore, 

consistent definitions and estimation methods must be used for 

each pool to ensure valid estimates of C stock changes (Eve et 

al. 2014, IPCC 2006).

Many of the estimation and sampling approaches used to 

account for C in agroforestry systems come from the forestry 

and agricultural literature. As such, it may be helpful when 

identifying estimation and sampling strategies to think about 

agroforestry practices and, even just within an agroforestry 

practice, as occurring within an agriculture and forestry 

continuum (figs. 3.1 and 3.2). Carbon in agroforestry practices 

that are dominated by agricultural crops (e.g., windbreaks) 

may be best accounted for using approaches developed for 

agricultural applications. Carbon in agroforestry practices that 

more closely resemble forest conditions (e.g., forest farming) 

may be best accounted for using methods developed in forestry. 

In other words, the distribution of C from agricultural fields to 

forest will dictate which models, measurements, and sampling 

design one chooses to quantify C stocks and stock changes.

This section focuses on C in perennial crops and soil organic 

matter as annual crops (i.e., most food crops and some forages, 

such as rye, oats, and wheat) are not typically included in C 

accounting. Live perennial biomass therefore includes live trees 

(above and below ground), shrubs, seedlings, and herbaceous 

vegetation (table 3.4). Some or all of these components of the 

live biomass pool may exist in agroforestry practices and in 

forest conditions; this pool accounts for as much as one-half of 

the C storage (EPA 2014). Dead wood includes standing dead 

trees and downed dead wood (table 3.4). Dead wood may be a 

negligible component of many agroforestry practices, but, in 

systems managed to more closely resemble forest conditions, 

one or both of these components may exist and be important 

contributors to the C stocks and fluxes. Litter and fine woody 

debris (table 3.4) are small but important components in forests 

and, although they may be minor components in agroforestry 

systems, approaches for estimating this ecosystem pool exist. 

Finally, SOC (table 3.4) is a major component in forests and 

agricultural landscapes and accounts for a substantial amount 

of C storage in these systems (EPA 2014).

Although inventory and sampling methodologies are beyond 

the scope of this chapter (see Pearson et al. [2007] for a 

description of C inventories), each ecosystem pool mentioned 

may exist in an entity-level accounting framework in agroforestry systems. For a complete description of entity-level 

accounting in agroforestry systems as it currently stands, see 

Eve et al. (2014).
Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions 53

Carbon Accounting at the Regional and 

National Levels

This section provides an overview of the assessment of C 

emissions and sinks resulting from the uses and changes in 

land types and forests in the United States, with emphasis 

on agroforestry systems. The IPCC Guidelines for National 

Greenhouse Gas Inventories (IPCC 2006) recommends 

reporting fluxes according to changes within and conversions 

between certain land-use types termed forest land, cropland, 

grassland, and settlements (and also wetlands). Agroforestry 

practices under the current organization of land-use categories 

in the U.S. National Greenhouse Gas Inventory (NGHGI) report are not explicitly characterized and, given the complex of 

land uses, may not be included in the national inventories used 

to compile C stocks and stock-change estimates for the United 

States (Perry et al. 2005, 2009). That said, agroforestry systems 

may be represented within the forest land (e.g., shelterbelts), 

cropland (e.g., alley cropping, windbreaks), or grassland (e.g., 

windbreaks, silvopasture) land-use types in the NGHGI if they 

meet the minimum definitions for each land use defined by the 

national inventories.

Land Representation in National Accounting

In accordance with IPCC (2006) guidelines for reporting 

GHG fluxes to the United Nations Framework Convention 

on Climate Change, the United States uses a combination of 

approaches and data sources to (1) determine areas of managed 

and unmanaged lands, (2) apply consistent definitions for the 

land-use categories over space and time, and (3) account for all 

C stock changes and non-CO2 GHG emissions on all managed 

lands (EPA 2014). Aspatial data from the Natural Resources 

Inventory (NRI) and FIA programs are used with spatially 

explicit time series land-use data from the National Land Cover 

Database (NLCD) to provide a complete representation of land 

uses and land-use change for managed lands. In general, land 

in the United States is considered managed if direct human 

intervention has influenced its condition and all other land is 

considered unmanaged (EPA 2014).

IPCC (2006) identifies six main land-use categories. In the 

United States, land-use definitions are country specific and 

are consistent with those used in the NRI and FIA programs. 

Agroforestry systems represent a complex of land use and 

management practices that intersect three distinct land-use 

categories in the NGHGI: (1) forest land, (2) cropland, and (3) 

grassland (table 3.4).

National Accounting Data Sources

The different land uses are monitored by national inventory 

programs that focus primarily on forest lands and agricultural 

lands. Because certain agroforestry practices may not meet the 

definitions of the different land uses used in national inventory 

programs, they may not be monitored (Perry et al. 2005). As 

a result, there is not sufficient data to characterize C stocks 

and stock changes at a national scale for certain agroforestry 

practices as required in national and international C reporting 

instruments. That said, the FIA program has several pilot 

studies currently under way to evaluate novel approaches to 

monitoring remote areas (e.g., interior Alaska), urban ecosystems, and tree cover in agricultural landscapes (Liknes et al. 

2010, Meneguzzo et al. 2013).

Natural Resources Inventory

The NRI is the official source of data on all land uses on 

non-Federal lands in the conterminous United States and 

Hawaii (except forest land), and it is also used as the resource 

to determine the total land base for the conterminous United 

States and Hawaii. The NRI is a statistically based survey 

conducted by the USDA Natural Resources Conservation 

Service and is designed to assess soil, water, and related 

environmental resources on non-Federal lands. The NRI survey 

uses data obtained from remote-sensing imagery and field visits 

to provide detailed information on land use and management, 

particularly for croplands and grasslands, and is used as the 

basis to account for C stock changes in agricultural lands 

(except Federal grasslands).

Forest Inventory and Analysis

The FIA program, conducted by the USDA Forest Service, is 

another statistically based survey for the United States; it is 

the official source of data on forest land area and management. 

The FIA program employs a three-phase annual inventory, 

with each phase contributing to the subsequent phase. Phase 1 

is a variance-reduction step in which satellite imagery is used 

to assign Phase 2 (P2) plots to strata (Bechtold and Patterson 

2005). P2 plots are distributed approximately every 2,428 ha 

across the 48 conterminous States of the United States and 

are visited every 5 to 10 years (i.e., 10 to 20 percent of plots 

are remeasured in each State each year). Each P2 permanent 

ground plot comprises a series of smaller fixed-radius plots 

(i.e., subplots) spaced 36.6 m apart in a triangular arrangement, 

with one subplot in the center. Tree- and site-level attributes—

such as diameter at breast height and tree height—are measured 

at regular temporal intervals on P2 plots that have at least one 

forested condition (USDA Forest Service 2013). Every 16th 

P2 plot is a Phase 3 plot where additional attributes on live 

and dead trees, forest floor, understory vegetation, and soils 

are sampled. This information is used to estimate C stocks 

and stock changes on managed forest land (i.e., direct human 

intervention has influenced its condition) in the United States.
54 Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions

National Land Cover Database

The NLCD is used as a supplementary database to account for 

land use on Federal lands (e.g., Federal grasslands) that are not 

included in the NRI and FIA databases. The NLCD land-cover 

classification scheme, available for 1992, 2001, 2006, and 

2011, has been applied over the conterminous United States 

(Homer et al. 2004) and also for Alaska and Hawaii in 2001. 

For the conterminous United States, the NLCD Land Cover 

Change Products for 2001 and 2006 were used to represent 

both land use and land-use change for Federal lands (Fry et 

al. 2011, Homer et al. 2004). The NLCD products are based 

primarily on Landsat Thematic Mapper imagery. The NLCD is 

strictly a source of land-cover information and does not provide 

the necessary site conditions, crop types, and management 

information from which to estimate C stock changes or GHG 

emissions on those lands.

Carbon Stocks and Stock Changes

The relevant land-use categories that may include agroforestry 

systems or the C pools that comprise agroecosystems include 

forest land, croplands, and grasslands. This section provides 

an overview of the estimation methods for C stocks and stock 

changes within the C pools relevant in agroforests by land-use 

category.

Forest Land

Five C pools are defined by the IPCC (2006) for estimating C 

stocks or stock changes in forest ecosystems. These pools are 

consistent with the pools defined in table 3.3, although live 

biomass is separated into aboveground and belowground components for national reporting. Forest ecosystem stock and flux 

estimates are based on the stock-change method, and calculations for all estimates are in units of C. Separate estimates are 

made for the five storage pools. All estimates are based on data 

collected from FIA plots and from models employed to fill gaps 

in field data (USDA Forest Service 2013). Carbon-conversion 

factors are applied at the disaggregated level of each inventory 

plot and then appropriately expanded to population estimates. 

A combination of tiers as outlined by IPCC (2006) is used. 

The Tier 3 biomass C values are calculated from FIA tree-level 

data. The Tier 2 dead organic and soil C pools are based on 

land use, land-use change, and forestry empirical or process 

models from FIA data. All C-conversion factors are specific 

to regions or individual States within the United States, which 

were further classified according to characteristic forest types 

within each region.

Croplands 

Changes in soil C stocks due to agricultural land use and 

management activities on mineral soils and organic soils are 

estimated according to land-use histories recorded in the USDA 

NRI survey (USDA-NRCS 2009). An IPCC Tier 3 model-based approach (Ogle et al. 2010) was applied to estimate 

C stock changes for mineral soils used to produce most annual 

crops (e.g., alfalfa hay, barley, corn, cotton, dry beans, grass 

hay, grass-clover hay, oats, onions, peanuts, potatoes, rice, 

sorghum, soybeans, sugar beets, sunflowers, tomatoes, and 

wheat) in the United States in terms of land area. The model-based approach uses the DAYCENT biogeochemical model 

(Del Grosso et al. 2001, 2011; Parton et al. 1998) to estimate 

soil C stock changes and soil N2

O emissions from agricultural 

soil management. Coupling the two source categories in a 

single inventory analysis ensures a consistent treatment of the 

processes and interactions between C and N cycling in soils. 

The remaining crops on mineral soils were estimated using an 

IPCC Tier 2 method (Ogle et al. 2003). The Tier 2 method was 

also used for very gravelly, cobbly, or shaley soils (greater than 

35 percent by volume). Mineral SOC stocks were estimated 

using a Tier 2 method for these areas because the DAYCENT 

model, which is used for the Tier 3 method, has not been 

fully tested for estimating C stock changes in certain cropping 

systems. An additional stock-change calculation was estimated 

for mineral soils using Tier 2 emission factors to account for 

enrollment patterns in the USDA Conservation Reserve Program 

after 2007, which was not addressed by the Tier 3 method.

Annual C emissions from drained organic soils in cropland are 

estimated using the Tier 2 method provided in IPCC (2006), 

with U.S.-specific C loss rates (Ogle et al. 2003) rather than 

default IPCC rates.

Grasslands

Changes in soil C stocks due to agricultural land use and 

management activities on mineral and organic soils for private 

grasslands are estimated according to land-use histories 

recorded in the USDA NRI survey (USDA-NRCS 2009). 

Land use and some management information (e.g., crop type, 

soil attributes, irrigation) were originally collected for each 

NRI point on a 5-year cycle beginning in 1982. In 1998, the 

NRI program initiated annual data collection, and the annual 

data are currently available through 2010. NRI points were 

classified as “grassland remaining grassland” back to 1990 

(the baseline year) if the land use had been grassland for 20 

years. Grassland includes pasture and rangeland used for grass 

forage production, where the primary use is livestock grazing. 

Rangelands are typically extensive areas of native grassland 

that are not intensively managed, while pastures are often 

seeded grassland, possibly following tree removal, that may 

or may not be improved with practices such as irrigation and 

interseeding legumes.

An IPCC Tier 3 model-based approach (Ogle et al. 2010) is 

applied to estimate C stock changes for most mineral soils 

in non-Federal grasslands remaining grasslands. The C stock 
Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions 55

changes for the remaining soils are estimated with an IPCC 

Tier 2 method (Ogle et al. 2003), including gravelly, cobbly, or 

shaley soils (greater than 35 percent by volume) and additional 

stock changes associated with sewage sludge amendments. 

Annual C emissions from drained organic soils in grasslands 

are estimated using the Tier 2 method provided in IPCC (2006), 

which uses U.S.-specific C loss rates (Ogle et al. 2003) rather 

than default IPCC rates, as described in the Cropland Remaining Cropland section for organic soils (IPCC 2006).

Advancing Greenhouse Gas Performance 

and Accounting in Agroforestry Systems

Agroforestry systems are purposely diverse and complex, deliberately mixing both forestry and agriculture components into a 

variety of practices, a variety of designs (e.g., species compositions, arrangements), and a variety of settings, and involving a 

variety of other forestry and agricultural management activities 

(i.e., fertilization, harvesting, grazing, and tillage) (box 3.1). 

The ability of agroforestry to confer its many ecosystem benefits 

from production to landscape health is attributable to this high 

functional and structural diversity (Olson et al. 2000). All these 

factors influence how much C can be sequestered and GHGs 

emitted or avoided, which means agroforestry affords us a very 

flexible and potentially powerful arrangement of options to improve GHG mitigation performance, along with other functions 

being sought from agriculture by producers and society.

Capitalizing on Agroforestry’s Complexity

Understanding how best to utilize these plantings in GHG 

mitigation strategies requires that we can understand, document, 

and account for all of agroforestry’s GHG impacts. Agroforestry 

practices are expressly designed to capitalize on the beneficial 

interactions generated among the tree, crop, and livestock 

components, the impacts of which may occur well beyond the 

area occupied by the agroforestry planting itself. For example, 

a crop windbreak is designed to favorably modify microclimate 

on the adjacent crop field, an impact that can extend up to a 

distance of 15 times the windbreak tree height (Brandle et 

al. 2009). Windbreak-induced shifts in crop growth and soil 

microclimate in the field adjacent to the practice can then 

potentially further alter soil C fluxes and N2

O emissions in 

the field. We must actually look beyond the C sequestered in 

the wood and soil just under the trees, as is done now, to fully 

capture agroforestry’s C benefits (fig. 3.2).

Interpractice soil C transfers also need to be considered in 

agroforestry GHG accounting. Many agroforestry plantings are 

explicitly designed to intercept or alter wind- and water-borne 

soil erosion, a climate change adaptive function that is 

predicted to become more critical under future weather events 

(see the Soil Resources section in chapter 2). Higher levels 

of soil C under windbreaks in the Great Plains and elsewhere 

are partially attributable to this interception of wind-blown 

soils (Sauer et al. 2007). These windbreak-intercepted soils 

have also been generally found to be richer in C (Sudmeyer 

and Scott 2002). Increased soil movement from upland fields 

into a riparian wetland area was associated with increased 

C sequestration rates in a riparian wetland (McCarty and 

Ritchie 2002). The more limited management and therefore 

more limited disturbance within riparian areas also suggest 

riparian forest buffers can serve as a longer term sink for C in 

this landscape. These erosional processes also deliver N into 

agroforestry practices, which is expected to influence N2

O flux 

in many different ways, depending on landscape position, site 

conditions, and vegetation and to also then impact C dynamics.

Species selections and planting configurations and densities are 

key considerations in designing for GHG mitigation-enhanced 

services from agroforestry. For instance, use of fast-growing 

species such as hybrid poplar can provide rapid C sequestration 

and N uptake, albeit with a shorter project duration than using 

slower growing species. Slower growing species, on the other 

hand, may be selected for the very purpose of longer function, 

such as in a windbreak, and thus have a longer project duration 

in which to sequester C. Mixtures of species, such as the 

herbaceous and woody plants used in riparian forest buffers, 

may be selected to optimize these GHG factors on site and also 

to provide other opportunities like biofeedstock production, 

which, in turn, would have additional GHG benefits (fig. 9.1 in 

chapter 9 of this assessment) (Schoeneberger et al. 2008). Other 

considerations can involve timing, placement, and type of 

N-fertilizer in agroforestry practices, where needed, and animal 

stocking numbers and rotation lengths in silvopasture systems 

(table 3.3). Many considerations can go into the planning and 

design of agroforestry, GHG mitigation being potentially one 

of them.

The various roles agroforestry can play in both GHG mitigation 

and climate change adaptation in U.S. agriculture—all depending on design and management—affords us the opportunity 

to rethink these practices in terms of optimizing benefits 

across the multiple objectives being sought for these lands 

(Schoeneberger et al. 2012). Waterbreaks are one example. 

A waterbreak is a planned floodplain system of linear woody 

buffers oriented to reduce flooding impacts (Wallace et al. 

2000). Properly designed and located, waterbreaks could help 

address the potential impacts of the increased frequency and 

intensity of flood events being predicted under climate change 

and can also provide enhanced GHG mitigation services and 

many other nonflood-related services (fig. 9.3 in chapter 9 of 

this assessment). Other examples are presented in chapter 9.
56 Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions

Accounting Needs

Advancements are being made in the approaches for 

determining relative values and directions of GHG impacts 

from agroforestry (see Ogle et al. 2014). Tools, like USDA 

COMET-Farm (http://www.cometfarm.nrel.colostate.edu), 

now available for entity-level C reporting and planning, 

have incorporated modules for agroforestry and other woody 

plantings. These tools can help land managers compare the 

relative amounts of GHG mitigation from the many different 

climate-smart management options available, including 

agroforestry.

As mentioned previously, although current GHG accounting in 

agroforestry is focused on C in the woody biomass and in the 

soil under the woody plants, full GHG accounting will need to 

take into account that (1) the agroforestry-influenced unit may 

be greater than just the agroforestry-planted area (fig. 3.2), and 

(2) spatial and temporal factors will need to be considered for 

the mixture of components (fig. 3.1 and fig. 3.3). For example, 

silvopasture requires not only the modification and coupling of 

crop and forestry accounting approaches, but also inclusion of 

accounting for the livestock. Again, at this time, accounting can 

essentially only be done for each individual component as if no 

interactions occur among the components. Work by Dube et al. 

(2011) in silvopasture, which involves the co-management of 

trees, forage, and animals, provides us a glimpse of the many 

integrated GHG dynamics in these highly integrated systems.

As an agricultural management activity, agroforestry GHG 

information needs are similar to those already identified for 

agriculture in general (Olander et al. 2013) and include—

• User-friendly methods that work across scales, regions, and 

systems.

• Lower cost, feasible (end users’ willingness to use) approaches.

• Methods that can crosswalk between emission-reduction 

strategies and inventories for reporting.

• Easily understood and common metrics for policy and 

market users.

• Continued research to account for and address the uncertainties in all the previous needs.

Although agroforestry practices have been part of the landscape 

for hundreds of years, they now reflect a wide variety of forms, 

management activities, and geographic settings. Performing the 

number of studies needed to adequately describe the performance 

of an agroforestry practice is physically and economically difficult. 

Regional and national coordination of agroforestry studies 

provides a more effective means to generate the necessary data. 

Standardization of measurement and modeling protocols would 

allow studies to be directly compared and the data then to be 

aggregated for additional research analyses and modeling efforts.

A Common Framework for Greenhouse Gas 

Accounting in Agroforestry

GHG assessments of agriculture’s many activities, including 

agroforestry, need to be compatible for maximum use of the 

data collected (i.e., to compare between activities and to aggregate the contributions of many activities into a whole-farm 

context) (Olander et al. 2013). To this end, the report Quantifying Greenhouse Gas Fluxes in Agriculture and Forestry: 

Methods for Entity-Scale Inventory was developed to create an 

Figure 3.3. Complexities of carbon sequestration accounting within an agroforestry practice as illustrated by an alley cropping/

silvopasture design. Accounting must be pragmatic, however, with the acknowledgment that accounting in agroforestry is not 

a 1+1=2 system but rather one in which 1+1 may be either greater than or less than 2, depending on the spatial and temporal 

factors influencing these interactive and long-lived systems.
Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions 57

updated standard set of GHG estimation methods for use by 

USDA, landowners, and other stakeholders to assist in GHG 

management decisions (Eve et al. 2014). Key considerations 

are consistent with IPCC (2006) and include—

• Transparency. Clearly explained assumptions and methodologies to facilitate replication.

• Consistency. Methods and estimates internally consistent 

between years and, to the extent possible, with other USDA 

inventory efforts.

• Comparability. Estimates of emissions and sequestration 

reported by one entity should be comparable to those 

reported by others.

• Completeness. Must account for all sources and sinks and 

also for all GHG to the greatest extent possible.

• Accuracy. Accurate estimates that are systematically neither 

over nor under true emissions or removals as far as can be 

judged.

• Cost-effectiveness. Balance between the relative costs and 

benefits of additional efforts to improve the inventory or 

reduce uncertainty.

• Ease of Use. Level of complexity of the user interface and 

underlying data requirements.

These considerations are especially relevant to agroforestry 

efforts in the United States. Efforts to build regional understanding and GHG accounting of agroforestry in the United 

States are currently limited by not only a lack of data but also 

by disparate sampling protocols and designs used between 

studies (Nair 2012b). A more coordinated approach that could 

be used among the agroforestry researchers within the United 

States, other North American countries, and other temperate 

regions would create a more cost-effective strategy for generating 

the data needed to inform GHG and climate change decisionmaking (Nair 2012b, Schoeneberger et al. 2012).

A logical place to begin framing a common approach to GHG 

assessment in agroforestry is perhaps best placed in the land 

use into which it is primarily deployed—agriculture. Such a 

coordinated approach is the USDA Agricultural Research Service’s 

GRACEnet (Greenhouse gas Reduction through Agricultural 

Carbon Enhancement network) effort (Liebig et al. 2012). 

GRACEnet provides a national framework for standardized 

approaches to assess C sequestration and GHG emissions from 

different cropping and rangeland systems, using common 

measurement protocols and coordinated regional experimental 

design (Walthall et al. 2012). By capitalizing on GRACEnet’s 

already-established framework and protocols, data generated 

should be readily comparable across agroforestry studies and 

practices as well as across the many other agricultural management practices, thereby enabling a more accurate whole-farm 

accounting.

Capitalizing on Agroforestry’s GHG and 

Adaptation Benefits

Pursuing agroforestry-derived GHG mitigation and climate 

change adaptation services simultaneously has technical and 

financial advantages (Duguma et al. 2014, Motocha et al. 2012, 

Plieninger 2011). GHG mitigation by agroforestry is dependent on 

having the plantings in place; however, adoption of agroforestry 

will be dependent on its cost-effectiveness, for whatever reason. 

Capitalizing on both the mitigation and adaptation services 

agroforestry can provide may help tip the balance in terms of 

cost-effectiveness for establishing new plantings. Carbon payments alone may influence adoption of agroforestry. However, the 

additional incentives tied to attainment of the adaptive services 

and goods agroforestry can also provide, such as protecting 

soil and air quality and providing critical wildlife habitat (e.g. 

pollinators), could lower the break-even prices even further and 

lead to greater adoption by farmers and ranchers (ICF 2013). 

Agroforestry also has the potential to generate additional income 

through diversified production and through hunting and other 

recreational fees, providing additional incentive. Use of these 

plantings as GHG mitigation strategies will ultimately hinge 

on the economics of agroforestry use (see chapter 4 in this 

assessment for further discussion of financial considerations 

regarding agroforestry) and on other producer values (see 

chapter 5 in this assessment for further discussion regarding 

adoption of agroforestry).

Key Findings

• Agroforestry plantings can sequester C in soils and biomass 

and mitigate other GHG emissions while leaving the bulk of 

land in agricultural production and providing other production, 

natural resource, and climate change adaptation services. 

• The C sequestration and indirect C (emission avoidance) 

benefits from agroforestry systems are generally comparable 

or larger in magnitude than many other agricultural management activities. With high rates of C sequestration per unit 

area, even small plantings like windbreaks can provide 

substantial contributions to whole-farm GHG mitigation. 

• Agroforestry’s other GHG mitigation services, while not all 

fully understood, appear to also contribute to the improvement 

of the GHG footprint of individual farm and ranch operations.

• The specifics of agroforestry design and management 

activities influence the amounts and duration of C sequestration and potential reduction in GHG emissions. As such, 

agroforestry, with its many components, provides a highly 

flexible and versatile management option to improve GHG 

mitigation and production services.
58 Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions

Key Information Needs

• Identification of land in the United States suitable, both 

biophysically and cost-effectively, for establishing the 

various agroforestry practices to optimize GHG benefits 

along with other services agroforestry can provide.

• A national inventory to cost-effectively track land currently 

in agroforestry with a description of plantings (e.g., practice, 

age, condition) over time to evaluate contributions and 

include within U.S. GHG inventory assessments.

• A common GHG assessment framework to efficiently 

advance measurement, understanding, and predictive 

capacity of agroforestry’s GHG services across the range of 

spatial and temporal settings in which agroforestry can be 

placed in the United States.

• Refined tools and methodologies for cost-effective and 

verifiable measurements/estimations of agroforestry’s longterm potential to mitigate GHG emissions within the many 

agricultural production systems across the United States.

• Criteria and design tools to assist producers in developing 

appropriate configurations, species selections, and planting 

densities in the various agroforestry practices that optimize 

GHG mitigation along with other ecosystem services, 

including adaptation of and by the plantings to extreme 

weather events and other climate change impacts.

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Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions 63

Chapter 4

Valuation of Agroforestry Services

D. Evan Mercer, Xiaoshu Li, Andrew Stainback, and Janaki Alavalapati

D. Evan Mercer is a research economist, U.S. Department of Agriculture, Forest Service, Southern 

Research Station (retired); Xiaoshu Li is a postdoctoral scholar, University of Kentucky, Department of 

Forestry; Andrew Stainback is an ecological economist, Everglades Foundation; Janaki Alavalapati is 

the Dean of the School of Forestry and Wildlife Sciences, Auburn University.

Rural communities and lands are particularly vulnerable to 

climate change (Lal et al. 2011). Changes in the viability of 

plants and animals; arid land expansion; reductions in water 

quantity and quality; increased threats from pests, diseases, and 

wildfire; and more frequent extreme weather events may induce 

a variety of economic and social impacts on rural communities. 

These impacts include increased uncertainty of food and fiber 

production, reduced supply of ecosystem services, changes in 

employment opportunities, and human (and nonhuman) population relocations (Lal et al. 2011). Reducing the vulnerability of 

rural communities requires developing agricultural and forestry 

production systems that are resilient to changing environmental 

conditions (Lin et al. 2008, Verchot et al. 2007). Chapters 2 and 3 

of this assessment demonstrate the potential for agroforestry to 

mitigate climate change (through increased carbon sequestration 

and reduced greenhouse gas [GHG] emissions) and assist 

rural communities in adapting to climate change by providing 

alternatives to conventional agricultural that are more resilient 

to the impacts of extreme weather events, changes in rainfall 

patterns, and increased risks from pests and diseases. Agroforestry, however, will make a significant contribution to mitigating or adapting to climate change only if landowners across the 

landscape adopt it in the United States (Scherr et al. 2012).

Economic theory predicts that farmers (who are price sensitive) 

will invest in agroforestry when the expected returns from the 

new system are higher than all other alternatives for the use 

of their land, labor, and capital. A large empirical literature 

confirms that a host of other factors also determine the extent of 

agroforestry adoption; these factors include household preferences, resource endowments, market incentives, biophysical 

factors, and risk and uncertainty (Mercer 2004, Mercer and 

Pattanayak 2003).1

 The role of risk and uncertainty, in particular, appears to be more important in agroforestry-adoption 

decisions compared with annual cropping innovations because 

of the long periods before the returns to tree growing are 

realized (Pannell 2003, Pattanayak et al. 2003).

Agroforestry systems also produce a number of important 

ecosystem services, such as carbon sequestration, biodiversity 

conservation, soil enrichment, and protection of air and water 

(Jose 2009). The value of these services to society is potentially 

quite high, but rarely are landowners paid for them. In many 

cases, agroforestry systems will be economically viable only 

when landowners are paid for producing these nonmarket 

services (Frey et al. 2010). Under these circumstances, it may 

be optimal for society to provide incentives to adopt agroforestry as evidenced by a number of Federal programs promoting 

agroforestry adoption (Godsey et al. 2009). Determining the 

optimal size of these incentives requires estimates of the value 

of the ecosystem services produced by agroforestry systems.

This chapter provides an overview of research on the economic 

valuation of agroforestry in North America. Economists have 

two approaches for valuing land-use systems: (1) financial 

analysis examines returns to investments from the landowner’s 

perspective and typically focuses on enterprise- or farm-level 

outcomes and (2) economic analysis expands the analysis to 

include societal impacts beyond the farm boundaries (i.e., externalities) (Thompson and George 2009). We organize this chapter 

using this typology. First, we examine the current literature on 

the valuation of agroforestry from the landowner’s perspective 

focusing on this question: “Under what conditions is agroforestry a 

viable financial enterprise for landowners?” We briefly review the 

various tools used for this type of analysis, including capital budgeting, production frontier analysis, and linear programming 

and their application to agroforestry. The second section of the 

chapter synthesizes the literature on the value of agroforestry 

from society’s perspective, emphasizing the valuation of the 

ecosystem services and both positive and negative externalities 

associated with agroforestry. Then, we review the recent 

literature on the role and impact of risk and uncertainty on the 

adoptability of agroforestry in the United States and end with a 

summary of key findings and information needs.

1

 Economic theory can also be used to explain the impact of these factors.
64 Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions

Valuation of Financial Returns to the 

Landowner

A range of methods and analytical tools has been used to 

estimate the financial returns to landowners from adopting 

agroforestry systems. These tools are summarized in table 4.1 

and discussed individually in the following paragraphs.

Capital Budgeting

Capital budgeting (cashflow or cost-benefit analysis) is the most 

widely used method for comparing the efficiency (profitability) 

of alternatives with different inputs and outputs (Klemperer 

1996). Net present value (NPV), the sum of the discounted 

periodic net revenues per unit of land during a given period, is 

the most common decisionmaking criteria in capital budgeting 

studies. When the NPV is higher for agroforestry than are 

all feasible alternatives, it is potentially adoptable. The soil 

expectation value (SEV), the net return per acre assuming 

perpetual rotations, is more appropriate when the time horizons 

of alternatives vary (for example, when comparing annual 

cropping to agroforestry). Multiplying SEV by the interest rate 

gives the annual equivalent value, which can be used to compare alternatives yearly. Other capital budgeting criteria include 

the benefit-cost ratio, which compares discounted benefits to 

costs as a ratio rather than a difference, and the internal rate of 

return, which is the discount rate at which the present value of 

benefits equals the present value of costs (i.e., the discount rate 

that makes the NPV equal zero).

Frey et al. (2010) applied capital budgeting techniques to 

compare financial returns from eight agroforestry and seven 

forestry systems with annual cropping on marginal lands in 

the Lower Mississippi Alluvial Valley. With few exceptions, 

annual cropping produced higher returns than agroforestry and 

forestry, even in the absence of Federal agricultural support 

payments. A few forestry and agroforestry systems, however, 

were competitive on marginal agricultural lands, assuming 

landowners could sell carbon sequestration credits. Holderieath 

et al. (2012) developed cashflow models to assess the adoptability of silvopasture and alley cropping in Missouri, with and 

without payments for carbon credits. They found that additional incentives from selling carbon credits were not sufficient to 

encourage adoption of silvopasture or alley cropping practices 

because the financial returns were so much lower than annual 

cropping. Godsey et al. (2007) applied cashflow analysis to 

compare the costs of converting upland hardwood forests in 

the Missouri Ozarks to silvopasture with the cost of traditional 

improved pasture and found that silvopasture can produce 

positive NPVs. Ares et al. (2006) examined nut, timber, and 

forage production and the economics of managed pecan 

silvopasture in southeastern Kansas. They estimated discounted 

cashflows and NPVs from 20-year Monte Carlo simulations 

of four agroforestry scenarios for pecan/cattle silvopasture 

operations. Using current nut and beef prices and discount rates 

of 6 and 8 percent, cashflows were positive during the 20-year 

simulation, but NPVs were negative; however, adding timber 

production to the system produced positive NPVs.

Stamps et al. (2009) used cashflow analysis to compare alley 

cropping alfalfa with black walnut to conventionally grown 

alfalfa in Missouri. Although cashflows for black walnut 

plantations were negative for decades, adding alfalfa production in wide alleys between the walnut trees produced positive 

cashflows. The annual equivalent value for alfalfa monoculture, 

however, was almost 50 percent higher than for the agroforestry system, and, without payments for the ecosystem services 

produced from the agroforestry system, widespread adoption 

was deemed unlikely.

Table 4.1. Financial valuation methods. 

Methods Definition Agroforestry examples

Capital budgeting Economic analysis to determine the relative profitability of investment alternatives. Decision criteria include net present value (NPV), soil expectation value 

(SEV), and annual equivalent value (AEV).

Frey et al. (2010)

Holderieath et al. (2012)

Godsey et al. (2007)

Ares et al. (2006)

Stamps et al. (2009)

Benjamin et al. (2000)

Graves et al. (2007, 2011)

Susaeta et al. (2012)

Linear programming Optimization of an outcome based on some set of constraints using a linear 

mathematical model.

Stainback et al. (2004)

Wojtkowski et al. (1988)

Mudhara and Hildebrand (2004)

Thangata and Hildebrand (2012) 

Dhakal et al. (2012)

Production frontier analysis Parametric and nonparametric econometric techniques for measuring the 

technical efficiency of alternative production systems.

Frey et al. (2012) 

Pattanayak and Mercer (1998)

Yin and Hyde (2000)

Lindara et al. (2006)

Gockowski et al. (2010)

Jahan et al. (2013)
Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions 65

Benjamin et al. (2000) used a discounted cashflow analysis to 

compare returns to hardwood (walnut) alley cropping systems 

with traditional forest plantation, row crop monoculture 

(corn), and annual crop rotations (corn-soybean-wheat) in the 

U.S. Midwest. During a 68-year rotation, widely spaced alley 

cropping systems produced the highest NPVs (with a 5-percent 

discount rate) followed by traditional walnut plantations, both 

of which were more than twice as high as the returns for annual 

crops during the same period.

Linear Programming

Linear programming (LP) models differ from capital budgeting 

in two important ways: (1) they analyze the entire farm, not 

just the activity of interest, and (2) they can account for farm 

diversity. Farm types are modeled separately and aggregated 

to evaluate potential adoptability across a landscape. When the 

landowners’ objective is to maximize long-term profits from 

the entire farm under multiple constraints, LP is usually the 

preferred analytical tool. LP models have been widely applied 

to agroforestry systems in the tropics (examples include Dhakal 

et al. 2012, Mudhara and Hildebrand 2004, Thangata and Hildebrand 2012, Wojtkowski et al. 1988), but we could find only 

one study that applied LP in temperate zones. In this study, 

Stainback et al. (2004) used dynamic optimization models to 

compare the profitability of silvopasture with conventional 

cattle ranching in southern Florida, with and without taxes on 

phosphorous runoff and payments for carbon sequestration. In 

the absence of taxes and carbon payments, traditional ranching 

produced higher SEVs than the silvopasture systems. Although 

phosphorous taxes alone were not enough for silvopasture to 

compete economically with traditional ranching, payments for 

carbon sequestration with or without phosphorous taxes could 

make silvopasture competitive.

Production Frontier Analysis

The production frontier, the maximum output that can be 

produced for any given level of input, is used to measure 

technical efficiency (TE). In one input/one output cases, TE 

is simply the slope of the line through the origin to any point 

on the production frontier. Measuring relative efficiency when 

faced with multiple inputs and outputs, however, is much more 

difficult. One approach is to use the ratio of the weighted inputs 

to weighted outputs. If all outputs and inputs have market 

values, the prices are the weights and TE is equivalent to the 

benefit-cost ratio. For situations in which markets are thin 

(small number of buyers and sellers), prices do not exist, and/

or farmers may lack access to markets, benefit-cost ratios may 

not be comparable between farms. In these cases, two methods 

(parametric and nonparametric) are available. Although a 

large and growing literature is applying parametric methods to 

analyze agroforestry in the tropics (e.g., Gockowski et al. 2010, 

Jahan et al. 2013, Lindara et al. 2006, Pattanayak and Mercer 

1998, Yin and Hyde 2000), we were unable to find any studies 

applying this approach to agroforestry in temperate regions.

Data envelopment analysis (DEA), the most common nonparametric alternative, uses LP to calculate the weights that 

maximize technical (or profit) efficiency. DEA is suited for 

comparing the efficiency of alternatives, even when market 

prices are not available for all inputs and outputs. DEA 

determines the weights (relative shadow prices) for each input 

and output that maximize efficiency. Although no studies 

in the United States using DEA could be found, Frey et al. 

(2012) applied DEA to compare the relative efficiency among 

silvopasture, conventional pasture, and plantation forestry in 

Argentina, after which, they applied nonparametric statistical 

analysis to compare the systems within farms. Silvopasture was 

found to be more efficient than conventional cattle ranching, 

but results were inconclusive for conventional forestry.

Valuation of Ecosystem Services and 

Externalities From Agroforestry

In addition to providing financial benefits to landowners, 

agroforestry can also generate substantial ecosystem services 

to the public, including carbon sequestration; biodiversity 

conservation; and protection of soil, air, and water (Jose 

2009). Ecosystem services, however, typically are not sold in 

markets and, therefore, cannot be valued directly with market 

prices. Designing optimal agroforestry policies (from society’s 

perspective) for mitigating and adapting to climate change 

requires estimating the value of these nonmarket ecosystem 

service benefits and applying them in benefit-cost analyses.

Nonmarket valuation methods have been widely used to 

estimate the value of ecosystem services, such as biodiversity, water quality, and recreation. Valuation methods are 

usually based on either stated or revealed preferences. Stated 

preference approaches, including contingent valuation and 

choice modeling, rely on surveys to directly elicit values from 

respondents. Revealed preference approaches like hedonic 

analysis use actual choices people make in real markets to infer 

how much they are willing to pay for environmental goods 

and services associated with those choices. Although demand 

for nonmarket valuation studies of ecosystem services from 

agroforestry is increasing, only a limited number of studies 

applied to U.S. agroforestry currently exist. Table 4.2 summarizes the available methods.
66 Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions

Table 4.2. Nonmarket valuation methods.

Methods Definition Agroforestry examples

Contingent valuation Stated preference method that asks the respondents whether they would like 

to pay (or accept) a set amount of money for certain environmental condition.

Grala et al. (2012)

Shrestha and Alavalapati (2004a)

Qiu et al. (2006)

Choice experiments Stated preference method that asks people to make choices based on two or 

more hypothetical conditions. A set of attributes, including environmental conditions, is described in each choice.

Shrestha and Alavalapati (2005)

Mercer and Snook (2004)

Hedonic analysis Revealed preference methods based on the assumption that the prices of 

household properties represent the sum of values associated with property 

attributes, including the environmental assets.

Bastian et al. (2002)

Shrestha and Alavalapati (2004b)

Vanslembrouck et al. (2005)

Benefit transfer Transfer of available information from existing literatures conducted in another 

location or conditions to estimate the benefit value of the current research 

condition.

Porter et al. (2009)

Kulshreshtha and Kort (2009)

Contingent Valuation

Contingent valuation is a survey method for estimating nonuse 

and passive use values in which respondents are asked how 

much they would be willing to pay or willing to accept for 

changes (positive or negative) in ecosystem service production 

under alternative land-use scenarios (Bateman et al. 2002, 

Mitchell and Carson 1989). Grala et al. (2012) employed 

contingent valuation to estimate the willingness of Iowa’s 

residents to pay for the aesthetic benefits associated with field 

windbreaks. Depending on their perceptions about the visual 

appeal and abundance of field windbreaks, Iowa residents were 

willing to donate on average from $4.77 to $8.50 to a fund to 

pay landowners to plant windbreaks. Qiu et al. (2006) valued 

the benefits of riparian buffer zones in a suburban watershed of 

St. Louis, MO. Respondents were willing to pay an additional 

$1,400 to $1,625 to live in a community accessible to a riparian 

buffer and $6,100 to $6,858 for properties adjacent to a riparian 

buffer. The above two cases showed that residents are willing 

to sacrifice part of their income to support the establishment 

of agroforestry for the externalities provided, such as aesthetic 

values.

Contingent valuation surveys also have been used to estimate 

farmers’ willingness to accept payments to supply various 

ecosystem services. For example, Shrestha and Alavalapati 

(2004a) investigated incentives for ranchers to adopt silvopasture 

in Florida. They found that natural attributes, such as wildlife 

presence, recreational hunting opportunities, and the presence 

of creeks increased the probability that ranchers would adopt 

silvopasture. To adopt silvopasture, however, ranchers would 

require an average price premium of $0.15 per pound for beef 

or a direct payment of $9.32 per acre per year. Buckley et al. 

(2012) investigated the willingness of farmers in the Republic 

of Ireland to install 10-meter-wide riparian buffer zones over 

5 years. Of farmers surveyed, 47 percent were willing to adopt 

the proposed riparian buffer zone if paid, on average, $1.51 per 

linear meter per year.

Choice Experiments

In contrast with contingent valuation, in which people are 

directly asked to state their willingness to pay (or accept; WTP) 

for changes in ecosystem services, choice experiments require 

respondents to choose from a series of two or more choice sets 

with options that contain various combinations of attributes 

for each choice (Hanley et al. 2001). Based on the statistical 

analysis of the respondents’ sets of choices, the impact of each 

attribute on willingness to pay for an ecosystem service can be 

estimated. The WTP for a specific policy scenario is the sum 

of the WTP for all its attributes. Choice experiments can be 

especially useful in evaluating policies with a varying set of 

possible characteristics. 

Two studies employed the choice experiment method to 

evaluate the preferences for several agroforestry attributes from 

the public’s and landowners’ perspectives. In the first study, 

Shrestha and Alavalapati (2005) used a choice experiment 

to estimate how much households in south-central Florida 

would be willing to pay for environmental goods and services 

produced by installing silvopasture systems in the Lake 

Okeechobee watershed of Florida. Three attribute levels were 

provided for each of the following environmental characteristics: (1) water-quality improvement, (2) carbon sequestration, 

and (3) wildlife habitat protection. The results indicated 

that an average household in south-central Florida would be 

willing to pay $30.24 to $71.17 per year for 5 years for the 

environmental benefits produced by silvopasture adoption. In 

the second study, Mercer and Snook (2004) describe a choice 

experiment to assess how different attributes of an agroforestry 

system influenced farmers’ willingness to adopt agroforestry in 

Campeche, Mexico. The attributes included labor requirements, 

technical assistance, forest conservation, plant availability, 

and production resources. The results showed that farmers had 

a strong preference for increasing forest cover to bequeath a 

better world to their children and that important factors for 

adopting agroforestry included technical assistance; accessibility of tree seedlings; and a mix of products, including timber, 
Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions 67

crops, and fruit trees. Choice experiment studies are able to 

estimate the respondents’ preferences toward both negative and 

positive attributes associated with agroforestry land—essential 

information for balancing different impacts in policy design.

Hedonic Analysis

The hedonic price method is a revealed preference method 

based on the assumption that the prices of real estate are 

determined by the values associated with property attributes, 

including environmental amenities (Palmquist 1991). The 

hedonic method has been used to estimate economic damages 

associated with air pollution or water pollution, the economic 

benefits of aesthetic views, and the value of nearby recreational 

opportunities. For instance, if people who live near agroforests 

value increased wildlife habitat or the aesthetics of including 

trees in an agricultural landscape, the property values of nearby 

residences would be higher than more distant residences.

Three studies estimated the benefits from agroforestry generated by the price premium in real markets, such as land value, 

rent, or hunting license revenues. In the first study, Bastian et 

al. (2002) employed a hedonic model to examine the impact of 

wildlife habitat, angling opportunities, and scenic vistas on the 

value of agricultural land in Wyoming. The results showed that 

visually diverse lands generate higher prices relative to those 

landscapes dominated by agricultural production. In the second 

study, Shrestha and Alavalapati (2004b) investigated the effect 

of ranchland attributes, such as parcel size, tree cover, and 

proximity to urban centers, on recreational hunting in Florida. 

The results suggest that the additional tree and vegetation cover 

for silvopasture practices could increase hunting revenues. 

For example, maintaining 22 percent tree cover on ranchlands 

could increase hunting lease revenues by $16.15 per acre per 

year, an opportunity to supplement income from cattle. In the 

third study, Vanslembrouck et al. (2005) analyzed the effect of 

rural landscapes on the demand for rural tourism in Flanders, 

Belgium. Results indicate that some agricultural activities, such 

as meadows and grazing cattle, have a positive impact on how 

much tourists are willing to pay for rural accommodation, but 

intensive annual crop cultivation has a negative impact.

Benefit Transfer

Benefit transfer techniques are commonly used to indirectly 

estimate values for ecosystem services when it is not feasible 

(because of time or resource constraints) to conduct studies on 

the site in question. A benefit transfer study collects data and 

results from previous studies performed in other locations or 

under different sets of conditions. The values of the benefits 

under study are then estimated by adjusting the results from 

the previous studies based on the similarities and differences 

between the studies’ geographic and socioeconomic focus and 

methodological approaches.

Although the benefit transfer method is much less costly than 

conducting new research, care must be taken when extrapolating results from one setting to another. Both the geographical 

and socioeconomic characteristics of study sites may influence 

the estimates of values for ecosystem services (De Groot et 

al. 2012, Smith and Kaoru 1990). Instead of applying per-unit 

value estimates directly from the existing literature, it is 

preferable to use the functional forms and parameter estimates 

in a meta-analysis to derive values specific for the new study.

Porter et al. (2009) estimated the value of pollination, 

biological control, and food production from a combined food 

and energy agroforestry system in Taastrup, Denmark, based 

on previous estimates for agricultural ecosystem services by 

Costanza et al. (1997). Kulshreshtha and Kort (2009) employed 

the benefit transfer method to estimate the value of soil-erosion 

reduction, air-quality improvements, GHG-emission reductions, 

improved water quality, enhanced biodiversity, and enhanced 

recreation activities in prairie shelterbelts in Canada based on 

information in published literature. The total benefits for the 

external value from shelterbelts were found to be more than 

$140 million Canadian ($90.5 million U.S.) at 2001 exchange 

rates (OZF Foreign Exchange Services 2016). The previous 

two studies employed benefit transfer to value ecosystem services from agroforestry; however, the value used from previous 

literature may have been based on agricultural or forest land. 

The study did not distinguish between different land scenarios.

Choosing which nonmarket valuation techniques to use to 

value ecosystem services from agroforestry should be based on 

the available information and program circumstances. Stated 

preference techniques usually rely on surveys to investigate 

hypothetical scenarios of agroforestry programs. Conversely, 

revealed preference techniques use observations on actual 

choices that people made in existing markets to measure 

preferences. Contingent valuation and choice experiments 

are usually used to evaluate the nonconsumptive value of 

ecosystem services, such as biodiversity or cultural values. By 

contrast, the hedonic method is usually used to evaluate the 

consumptive values of agroforestry, such as aesthetic value or 

recreation. The limitation with stated preference methods is that 

the results are sensitive to numerous sources of bias in survey 

design and implementation. Although hedonic models avoid 

the potential problem with hypothetical responses, it requires a 

large amount of data that is largely limited to observable states 

of the world. In addition, hedonic results may be of limited 

value when markets are distorted, choices are constrained by 

income, or information about environmental conditions is 

scarce. Benefit transfer methods are used when resources and 

time are limited, such as when a large number of ecosystem 

services are being valued over a large area, and when sufficient 

numbers of previous studies are available to draw on.
68 Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions

Risk and Uncertainty

Variability in returns and the ability to change or postpone 

decisions when conditions change are important decision criteria 

for landowners. Because deterministic models assume that 

landowners/managers have perfect foresight of future conditions, 

they are not appropriate in the face of risk or uncertainty. A variety 

of stochastic models, however, can be used to incorporate risky 

or uncertain future conditions. Using both stochastic and deterministic models can provide important insights about financial 

decisions (Frey et al. 2013). Table 4.3 lists the available methods 

with examples from the agroforestry literature.

Mean-Variance Analysis

Mean-variance analysis (often referred to as E-V for “expected 

value/variance”) can identify the set of “efficient” alternatives 

that either minimize risk for any given level of returns or 

maximize returns for any given level of risk. Although E-V is a 

powerful tool for decisionmaking, the underlying assumptions 

about utility functions and distributions of returns often conflict 

with economic theory. Nevertheless, E-V is appropriate under 

a wide variety of utility functions and common levels of risk 

aversion (Kroll et al. 1984). Lilieholm and Reeves (1991) used 

E-V to model the efficient allocation of agroforestry within the 

whole farm and used simulation to show that adopting agroforestry can be optimal for certain levels of risk aversion.

Frey (2009) applied E-V to examine the tradeoffs between returns and risk in the Lower Mississippi Alluvial Valley and the 

potential for reducing risk by adopting agroforestry systems. 

He found that diversifying annual row crop production with 

cottonwood, pecan, and silvopasture can reduce whole-farm 

risk substantially, particularly on marginal land. The farmers, 

however, face a tradeoff between reducing variation of returns 

(with agroforestry) or maximizing the expected value of the 

returns (annual cropping). Additional research is needed to 

determine when, where, and why farmers would be willing to 

choose agroforestry in these circumstances. We could find no 

other temperate zone E-V analyses of agroforestry. Analyses 

for tropical agroforestry include Ramirez and Sosa (2000) and 

Babu and Rajasekaran (1991).

Stochastic Dominance

Because of less restrictive assumptions, stochastic dominance 

(SD) can be used when E-V is inappropriate (Hadar and Russell 

1969). Results are less deterministic than E-V but typically 

provide only a partial ranking of efficient and inefficient alternatives. Therefore, SD is commonly used to estimate a partial 

ordering based on partial information for initial screenings of 

alternatives (Hildebrandt and Knoke 2011). No examples of 

studies assessing temperate zone agroforestry with SD were 

found; however, Castro et al. (2013) and Benítez et al. (2006) 

applied SD to analyze the uncertainties associated with using 

conservation payments to preserve shade coffee in Ecuador.

Real Options

Management flexibility varies widely between land-use alternatives, and the ability to change or postpone actions can be 

crucial to the decision to adopt one system rather than another. 

One approach for incorporating uncertain future conditions 

is to apply real options (RO) techniques to estimate the value 

of flexibility for the alternatives. The key difference between 

RO and capital budgeting is the recursive nature of the RO 

decisionmaking process; i.e., RO provides an estimate of the 

value of being able to delay current-year decisions until future 

conditions are known (e.g., timber harvest and reforestation 

decisions).

Frey et al. (2013) used RO to analyze how the variability of returns and the flexibility to change or postpone decisions (option 

value) affect the returns to forestry and agroforestry systems, 

the adoption potential, and disadoption risk of agroforestry and 

production forestry in the Lower Mississippi Alluvial Valley. 

Due to the higher opportunity costs associated with converting 

from forests to agriculture, the option value provided by 

agriculture outweighed the forestry and agroforestry systems. 

The adoption potential of forestry and agroforestry was reduced 

when landowners took into account the flexibility provided by 

annual cropping systems as compared with tree-based systems, 

suggesting that simple cashflow analyses may overstate the 

adoptability of agroforestry in some cases.

Table 4.3. Incorporating risk and uncertainty.

Methods Definition Examples

Mean-variance analysis Mathematical analysis of effects of risk and expected returns to a portfolio of 

investments to identify the set of “efficient” alternatives that either minimize risk 

for any given level of returns or maximize returns for any given level of risk.

Frey (2009)

Lilieholm and Reeves (1991)

Ramirez and Sosa (2000) 

Babu and Rajasekaran (1991)

Stochastic dominance Method for comparing different distributions of outcomes among alternatives. Castro et al. (2013) 

Benítez et al. (2006)

Real options Method that takes into account strategic management options of alternatives 

and the flexibility to exercise or abandon the options at different points in time.

Frey et al. (2013)

Behan et al. (2006)

Isik and Yang (2004)

Wolbert-Haverkamp and Musshoff (2014)
Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions 69

Using RO models, Behan et al. (2006) also found that Irish 

farmers would wait longer to reforest/afforest than suggested 

by standard discounted cashflow analyses because of high 

establishment costs and the relative irreversibility of switching 

to forestry. Isik and Yang (2004) applied RO to examine 

participation in the Conservation Reserve Enhancement 

Program in Illinois. Although option values, land attributes, 

and farmer characteristics significantly influenced participation, 

uncertainties in crop prices and program payments and 

irreversibility associated with fixed-contract periods were also 

crucial. Wolbert-Haverkamp and Musshoff (2014) applied RO 

analysis to examine farmers’ options to integrate short rotation 

woody crops into traditional agricultural cropping systems in 

Germany. They found that the conversion triggers calculated 

with RO analysis are higher than predicted with classical 

investment theory and that risk-averse farmers would be 

expected to convert earlier from rye production to short rotation 

woody crops than risk-neutral farmers.

Summary and Conclusions

Research suggests that agroforestry systems may help mitigate 

climate change through carbon sequestration, rehabilitation of 

degraded lands, and stabilization of ecosystems by increasing 

resilience to climate change impacts through soil and water 

conservation, nutrient recycling, food security, biodiversity, 

and climate regulation (Lasco et al. 2014). The impact of 

agroforestry, however, will be limited by the extent of its 

adoption across the landscape, which currently remains quite 

low in the United States. This chapter examines the available 

economics literature on the value of agroforestry from both 

a landowner (net revenues) and a societal perspective (value 

of externalities). Although the literature is very thin, most 

of the economic studies of agroforestry in the United States 

that we were able to locate suggest that financial returns to 

adopting agroforestry are rarely competitive with modern 

annual agriculture unless incentives or payments for carbon 

sequestration and other ecosystem services are included. From 

a societal perspective, a few studies have applied nonmarket 

valuation techniques to value ecosystem services associated 

with agroforestry and have found significant willingness to pay 

by U.S. residents for the external ecosystem services produced 

by agroforestry. The available literature, however, is too small 

to make definitive statements concerning the economics and 

adoptability of agroforestry in the face of climate change.

Key Findings

• Under current policy and economic conditions in the United 

States, agroforestry has the most promise for soils that are 

marginal for annual monocultures. It is unlikely to compete 

financially with modern monocultures on highly productive 

lands. 

• The role of risk and uncertainty appears to be more important 

for adopting agroforestry than for annual cropping innovations, 

given the longer planning horizons required for implementing and managing agroforestry. Studies used to assess risk 

suggest that diversified systems like agroforestry may reduce 

whole-farm risk but at a cost of lowering total expected 

returns to the farm. 

• An increasing number of studies are employing nonmarket 

value evaluation methods to measure the value of biodiversity, water quality, recreation, and other ecosystem services 

from agroforestry systems. Studies indicate that, when 

incentives or payments for ecosystem services are included, 

agroforestry can be competitive with conventional cropping 

and livestock systems.

Key Information Needs

• The literature on the economics of agroforestry in temperate 

zones and, particularly, in the United States is very limited. 

Additional information is needed on financial and economic 

valuation, risk analysis, and how they influence adoptability 

of agroforestry in the United States.

• More nonmarket valuation studies of ecosystem services 

produced by agroforestry are needed, especially for those 

services benefitting society (biodiversity, water quality). 

• More studies are needed to compare the ecosystem service 

benefits of agroforestry ecosystems with modern annual 

agriculture, plantation forestry, or forested ecosystems. 

• Research is needed to quantify and understand future 

adoptability of agroforestry under a changing climate.

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72 Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions
Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions 73

Chapter 5

Human Dimensions of Agroforestry Systems

Kate MacFarland

Kate MacFarland is an assistant agroforester, U.S. Department of Agriculture (USDA), Forest Service, 

USDA National Agroforestry Center.

Contributors: Craig Elevitch, J.B. Friday, Kathleen Friday, Frank K. Lake, and Diomy Zamora

Craig Elevitch is the director of Agroforestry Net; J.B. Friday is the extension forester, University of Hawaii 

at Manoa College of Tropical Agriculture and Human Resources Cooperative Extension Service; Kathleen 

Friday is the Forest Legacy/Stewardship program manager—Hawai’i and Pacific Islands, USDA Forest 

Service, Pacific Southwest Region, State and Private Forestry; Frank K. Lake is a research ecologist, 

USDA Forest Service, Pacific Southwest Research Station; Diomy Zamora is an extension professor of 

forestry, University of Minnesota Extension.

The success of agroforestry in adapting and mitigating climate 

change depends on many human dimensions surrounding agroforestry. This chapter reviews research on the adoption of new 

practices by landowners and examines cultural perspectives on 

agroforestry. Diverse and complex motivators for conservation 

decisionmaking reflect the diversity of landowners, land 

management practices, and ecosystems and provide a variety of 

opportunities to encourage agroforestry adoption.

The chapter also reviews tribal and indigenous systems as models 

for modern resiliency. Affirmation of time-tested traditional 

agroforestry practices will help raise awareness and appreciation of traditional knowledge, with due respect to its indigenous 

origins. These diverse practices can play a vital role in reducing 

food insecurity, particularly on U.S.-affiliated tropical islands 

where the majority of food is imported. Practices by American 

Indians across the United States and practices on U.S.-affiliated 

tropical islands are highlighted and discussed in terms of 

building resilient operations, landscapes, and communities.

Agroforestry Adoption Constraints and 

Opportunities

Land managers are the gatekeepers to the realization of 

agroforestry’s climate mitigation and adaptation potential. 

Understanding how land managers make decisions is central 

to determining what role agroforestry can and will play in 

climate-smart strategies. Few studies focus on the adoption 

of agroforestry practices in the United States (e.g., Raedeke 

et al. 2003, Valdivia et al. 2012). Information can be gleaned, 

however, from research on land managers’ decisionmaking 

regarding other types of conservation practices. This research 

suggests diverse and complex motivators and factors for conservation decisionmaking, reflecting the diversity of landowners 

and land managers, land management practices, and ecosystems 

involved (e.g., Baumgart-Getz et al. 2012, Knowler and Bradshaw 

2007, Napier et al. 2000, Pannell et al. 2006, Prokopy et al. 2008). 

The decision to adopt and implement conservation practices is 

made by land managers for economic and cultural objectives 

and is influenced by knowledge from other practitioners and 

available technical guidance. Several models that describe 

the adoption of conservation practices and can help to explain 

agroforestry adoption are presented in the ensuing paragraphs.

Climatic variability and climate change make conservationrelated decisionmaking more complex. Understanding farmers’ 

attitudes toward climate change-motivated adoption of conservation practices has been found to be important in the United 

States (Barnes and Toma 2011, Prokopy et al. 2015). Farmers, 

in general, are more interested in adapting to climate change 

than mitigating greenhouse gases (Prokopy et al. 2015). Arbuckle 

et al. (2013) found that farmers may be willing to adapt to 

climate change, even though they may not think it is human 

caused or may not think it is happening at all. In their study, 

62 percent of Iowa farmers surveyed said they would need to 

do more to protect their land from climate change in the future, 

but only 33 percent thought the government should do more to 

reduce greenhouse gases and other causes of climate change 

(Arbuckle et al. 2013). These findings suggest that farmers 

and other land managers could be better engaged by focusing 

on the impacts of climate change (and agroforestry’s adaptive 

capacities) rather than on mitigation.
74 Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions

Practitioner Motivations To Use Agroforestry

When discussing how adoption of agroforestry practices 

happens, it is important to consider who makes the decisions 

to implement these practices. Current and potential adopters 

of agroforestry practices are not a uniform group (fig. 5.1). 

Climatic variability and climate change are only two of many 

possible motivators and considerations that influence a land 

manager’s decision to change his or her practices. Other factors 

in conservation practice adoption models include landowner 

and land manager demographics, farm characteristics, and 

landowner attitudes (Skelton et al. 2005). Farm structure, 

with variables such as the size of the farm, crop and product 

diversification, land tenure, and existing conservation practices, 

drives other models of adoption of conservation practices (for 

American Indians, see Mondou 1998). Landowners’ economic 

bottom lines and climate change mitigation are among many 

factors of adoption. Categorizing potential agroforestry 

adopters can offer basic guidance for targeting adoption 

strategies (table 5.1).

Barriers to Agroforestry Adoption

Many of the barriers to agroforestry adoption by land managers 

in the United States are the same as the barriers to other types 

of change. Theories about adoption of conservation practices 

are typically focused on economics (for more information on 

economics and agroforestry, see chapter 4). Although profit is a 

key motivator (Cary and Wilkinson 1997), profit maximization 

alone is not a reliable predictor of implementation of a particular agroforestry practice (Skelton et al. 2005). Decisionmaking 

about profit is mediated by other considerations, such as 

income diversification and reducing income risk (Zinkhan and 

Mercer 1997). Other factors besides economic considerations 

can be barriers to adoption (table 5.2).

Lack of information about how to implement and integrate 

agroforestry systems into their existing enterprises may be one 

of the most significant barriers for landowners. Survey results 

in Pennsylvania revealed that, although many landowners 

were interested in agroforestry (90 percent), most respondents 

did not have enough information about implementation, 

management, and marketing to follow through with adoption 

(Strong and Jacobson 2005). In a survey of U.S. extension 

professionals with responses from 32 States, about one-half 

of respondents (23 of 45 respondents), representing 16 States, 

provided programs in agroforestry (Jacobson and Kar 2013). 

These survey results suggest many States lack capacity in 

agroforestry. Information on revenue-generating specialty 

crops within agroforestry systems is also lacking (Gold et al. 

2004a, 2004b). Enterprise budgets and decisionmaking models 

for these specialty crops are also limited, which makes it harder 

to get loans from traditional farm lending organizations.

Figure 5.1. Agricultural producers are a diverse group, each with their own motivations, characteristics, resources, and attitudes 

that can influence decisionmaking regarding agroforestry. (Photos (L-R) courtesy of Lynn Betts, Bob Nichols, Ron Nichols, Ron 

Nichols, Tim McCabe, Bob Nichols, USDA Natural Resources Conservation Service and USDA Office of Communications).
Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions 75

Table 5.1. Generalized list of potential agroforestry adopters and some of their common motivations and characteristics that can 

influence adoption of agroforestry practices. 

Potential adopters Common motivations and characteristics Reference

Large-acreage farmers • Avoid potential environmental regulation by using practices to reduce negative 

offsite impacts.

• Increase yield and profit.

Skelton et al. (2005)

Small-acreage farmers • Diversify farm operations and income sources.

• Lower risk to volatile markets and extreme weather events.

• Meet increasing interest in local and organic markets.

• Often have nonmanaged woodlands with agroforestry potential.

Jordan (2004), 

Lasco et al. (2014), 

Raedeke et al. (2003), 

Workman et al. (2004) 

Limited-resource farmers • Increase food security.

• Diversify farm operations and income sources.

• Reduce input costs by relying on agroforestry practices to provide biological 

services.

Raedeke et al. (2003)

Beginning farmers and ranchers • Easier to integrate agroforestry into new operations.

• More likely to participate in cost-share programs that can be used to implement 

agroforestry practices.

• More likely to implement agricultural best management practices.

Mishra and Khanal (2013), 

Prokopy et al. (2008), 

USDA NASS (2014)

Tribes and indigenous groups • Sustain culturally significant food and fiber systems.

• Diversify farm and ranch operations and income sources.

• Encourage economic development.

• Increase food security.

Mondou (1998)

Ranchers, confined animal 

operations

• Avoid potential environmental regulation by using practices to reduce negative 

offsite impacts.

• Enhance public relations by using sustainable practices.

• Increase production and profit.

Gillespie et al. (2007)

Ranchers, free-range or 

pasture-based operations

• Diversify ranch operations and income sources.

• Increase interest in local and organic markets.

• Lower risk to volatile markets and extreme weather events.

Gillespie et al. (2007), 

Workman et al. (2004) 

Woodland owners • Provide income independent of timber harvesting activities.

• Diversify income for part-time or nontraditional owners.

Valdivia and Poulos (2009), 

Vaughan et al. (2013)

Public and nonprofit land 

managers

• Accomplish public goals for natural resources.

• Provide demonstration sites and opportunities for learning.

Garrett and Buck (1997), 

Garrett et al. (2004), 

USDA (2015)

Table 5.2. Barriers to agroforestry adoption by land managers.

Barrier Description Reference

Cost • Tree and shrub establishment is perceived to be costly. Valdivia et al. (2012)

Labor • Agroforestry practices can involve more labor to manage. AFTA (2000)

Lack of crop insurance • Crops produced from agroforestry systems may be perceived as riskier than 

commodity crops if crop insurance is not available for the agroforestry crops.

Young et al. (2001)

Lack of support for traditional 

tribal agroforestry systems

• Government programs have favored intensive commodity crops rather than tribal 

agroforestry practices.

Cleveland et al. (1995), 

Teel and Buck (1998)

Time • Agroforestry practices require a longer management timeframe and have a longer 

expected period for return on investment.

Raedeke et al. (2003), 

Valdivia et al. (2012)

Climate change impacts • Uncertainty about future climate can inhibit landowners from investing in longer 

term agroforestry systems.

Kirilenko and Sedjo (2007)

Uncertain land tenure • Land renters have less incentive to install practices that take time to return 

benefits of which they may not receive value.

Raedeke et al. (2003)

Complexity • Agroforestry increases agricultural production system complexity and landowners 

are generally averse to adding complexity.

• Agroforestry practices may be incompatible with farmers’ existing equipment or 

other fixed capital assets.

• Adding complexity is particularly challenging when existing production systems 

are fairly simple.

Valdivia et al. (2012)

Lack of information • Agronomists and farmers generally have little experience in planning and 

managing agroforestry practices.

Coggeshall (2011), 

Finn et al. (2008), 

Gold et al. (2004a), 

Gold et al. (2004b), 

Jacobson and Kar (2013), 

Warmund et al. (2010)
76 Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions

Support for Agroforestry Adoption

Significant support exists for increasing agroforestry adoption. 

Some of this support directly addresses barriers discussed in 

the previous section, and other support provides a starting point 

for addressing those barriers. The various types of support include—

• Policy support.

▪ U.S. Department of Agriculture (USDA) Agroforestry 

Strategic Framework.

▪ USDA Departmental Regulation on agroforestry.

▪ Whole-Farm Revenue Protection (WFRP) pilot program.

• Partnerships.

▪ Association for Temperate Agroforestry (AFTA).

▪ Landowner associations.

▪ Tribes and intertribal consortia. 

▪ Crop-processing cooperatives.

▪ Crop-specific support groups.

• Agroforestry education and technical support.

• Incentives.

Policy Support

Policy support for agroforestry at the Federal level is primarily 

through the USDA and its agricultural and forestry-based 

agencies. Increasing support from the USDA has been helpful 

in addressing the cost, time, complexity, and information constraints to agroforestry adoption. In 2011, the USDA released 

its USDA Agroforestry Strategic Framework Fiscal Year 

2011–2016, which outlines the USDA’s approach to agroforestry (USDA 2011). This framework created the Agroforestry 

Executive Steering Committee (which includes eight USDA 

agencies) to guide framework implementation. These actions 

increased Department-wide knowledge of agroforestry, enhancing the accessibility of agroforestry-related USDA lending 

and cost-share programs as USDA employees grow more 

knowledgeable about the risks and benefits of agroforestry. The 

USDA Departmental Regulation on agroforestry also created a 

consistent definition of agroforestry for all agencies to refer to, 

allowing for more programs to explicitly mention agroforestry 

in their guidance (Vilsack 2013).

As an outcome of this strategic framework, the first comprehensive report on agroforestry was released by USDA in 

2013—Agroforestry: USDA Reports to America, Fiscal Years 

2011–2012 (USDA 2013b). A more comprehensive version 

was released in 2015 (USDA 2015). This report quantifies current agroforestry activities taking place both on the American 

landscape and within USDA, creating a baseline of information 

on agroforestry at the Federal level. One question in the 2012 

Census of Agriculture addressed the adoption of silvopasture 

and alley cropping (USDA Census of Agriculture 2014). Inclusion 

of this question adds to the baseline information about agroforestry adoption in the United States. Other Federal policy 

changes, such as the WFRP pilot program—a USDA Risk 

Management Agency program for specialty and diversified 

crop producers—may also decrease risks for agroforestry 

producers with multiple crops. This program provides insurance coverage for the whole-farm enterprise, rather than for 

a single crop. It also insures farms with specialty or organic 

commodities (both crops and livestock) and those marketing 

to local, regional, farm-identity preserved, specialty, or direct 

markets (USDA RMA 2014). This coverage may be useful for 

agroforestry producers, who tend to have diversified operations.

In other instances, Federal policies affecting tribes have pushed for 

commercialization and modernization of tribal agriculture, which 

has been at the serious detriment of traditional and sustainable 

agroforestry systems (Cleveland et al. 1995, Mondou 1998). 

The American Indian Agricultural Resource Management 

Act (AIARMA 1994) has implications regarding how tribes 

maintain traditional and adopt modern agricultural systems 

(Mondou 1998). This act, which defines “agricultural product” 

to include crops, livestock, forage and feed, grains, and any 

other marketable or traditionally used materials, may be a 

vehicle to support tribal agroforestry (Mondou 1998). The 

U.S. Department of the Interior (DOI) Secretarial Order 3289, 

Addressing the Impacts of Climate Change on America’s 

Water, Land, and Other Natural and Cultural Resources details 

governmental programs that might be used to support tribal 

agroforestry under climate change (Salazar 2009).

Partnerships

Social networks are known to play a significant role in the diffusion of agricultural innovations (Jackson-Smith and McEvoy 

2011, Prokopy et al. 2008). Factors affecting diffusion include 

exposure to information from institutional and noninstitutional 

sources, including opinion leaders in the farm community and 

extension agents (Skelton et al. 2005). Agroforestry proponents 

and practitioners have embraced this social network-based 

approach by forming a variety of partnerships through peer-topeer networks of either agroforestry landowners or agroforestry 

extension professionals or both.

Some of these networks and working groups exist at the regional 

level, sharing information on crop varieties, markets, policies, 

and programs that come from a shared political, ecological, 

and economic situation. Like organic producers, agroforestry 

producers have developed this knowledge collaboratively 

(Parker and Lillard 2013). Farmers get most of their important 

information about agricultural conservation practices from family, friends, and neighbors (Jackson-Smith and McEvoy 2011) 

and are more dependent on farmer-to-farmer networks than 

information that comes from the top down from organizations 

(Valdivia et al. 2012).
Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions 77

This peer-to-peer approach can be effective in facilitating 

farmers’ decisionmaking by helping to diffuse information 

about particular practices and support (Ingram 2008). Many of 

the peer-to-peer networks related to agroforestry advocate for 

a variety of conservation practices. This approach is helpful 

because landowners tend to integrate agroforestry into their 

existing operations in conjunction with other conservation 

practices and maintain nonagroforestry systems on their farms. 

Many of these national networks are connected to one another 

through national and international organizations, such as 

AFTA, that seek to promote the wider adoption of agroforestry 

by landowners in temperate regions of North America.

Landowner associations, specialty crop-processing cooperatives (i.e., cooperatives that share processing infrastructure), 

and crop-specific support groups (e.g., North America Aronia 

Cooperative, the Upper Midwest Hazelnut Development 

Initiative) can also be helpful to landowners interested in 

agroforestry. Many specialty agroforestry products are 

economically viable only with processing, which can require 

equipment a single landowner may not be able to afford.

Many programs seek to improve conservation outcomes at a 

landscape scale across “all lands” (including public, tribal, and 

private lands). At the Federal level, some of these programs 

include the Two Chiefs’ Joint Landscape Restoration Partnership, the Collaborative Forest Landscape Restoration Program, 

and the Joint Fire Science Program. Agroforestry provides a 

way for these programs, which are often primarily focused 

on forest lands, to achieve conservation outcomes on private 

agricultural lands as well.

Agroforestry Education and Technical Support

Along with increasing information shared through partnerships, 

technical capacity related to agroforestry can be increased 

through education supported by Federal, State, tribal, and academic programs (e.g., Cooperative State Research, Education, 

and Extension Service, Federally Recognized Tribes Extension 

Grant Program). These programs generally target landowners 

and technical service providers. Deficiencies in the availability 

of formal and informal agroforestry training in temperate areas 

have long been noted (Nair 1993). Numerous training events 

have taken place during the intervening years that address this 

issue of increasing technical capacity (USDA 2015). Many of 

these training events target technical service providers who 

work with landowners. AIARMA (1994) provides opportunities for Federal training of tribes and members interested in 

an agricultural study program. Programs include, but are not 

limited to, agricultural economics, animal science, biological 

sciences, geographic information systems, horticulture, range 

management, soil, and veterinary science, all of which pertain 

to agroforestry practices and systems (Mondou 1998).

Although some studies have shown that education may be a 

more effective motivator than financial assistance for some 

landowners, the overall efficacy of education campaigns on 

the adoption of best management practices is still inconclusive 

(Prokopy et al. 2008, Skelton et al. 2005). Lassoie et al. (1994) 

noted the importance of education that not only addresses 

the mechanics of “how to” but also includes information on 

landowner motivations and effective integration of agroforestry 

into existing systems. Additional understanding related to how 

educational efforts should be structured to impact agroforestry 

adoption is needed and is being carried out through existing 

Sustainable Agriculture Research and Education grants.

Postsecondary education and training in agroforestry are 

available, though limited, with fewer than 20 colleges and 

universities offering graduate coursework in the field (Gold and 

Jose 2012, USDA 2015). Increasing postsecondary education 

capacity may be necessary. A need also exists to support tribal 

colleges to increase agricultural, forestry, and range educational 

programs as a means for expanding tribal agroforestry opportunities (Mondou 1998: 410):

Unless the education of Native American Indians in 

all facets of agriculture is made available and accessible, 

the possibility of revenue generating agricultural enterprises is remote for tribes that lack sufficient capital 

to fund the education of willing and able students.

Creating a certification program for agroforesters has been 

proposed to address the lack of information among technical 

service providers (Mason et al. 2012). This proposed program 

would be developed jointly among the Society of American 

Foresters, American Society of Agronomy, Crop Science 

Society of America, and Soil Science Society of America.

Incentives

Because cost is an important constraint to the adoption of 

agroforestry systems, financial assistance programs have been 

developed for conservation practices, including agroforestry 

practices. Although financial assistance alone is not enough to 

motivate farmers to adopt conservation practices, conservation 

practices that are profitable are more likely to be implemented 

(Napier et al. 2000). A variety of government incentive programs 

support agroforestry practices at the Federal, regional, and State 

levels. Details about Federal incentive programs are described 

in chapter 6. At the regional level, additional incentives may 

exist to address particular natural resource concerns, such as 

the Chesapeake Bay Program that provides implementation 

funds for riparian forest buffers to address nutrient management 

problems in that region. Market incentives through ecosystem 

services markets may also encourage agroforestry practice 

adoption.
78 Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions

Indigenous Systems as Models for Modern 

Resiliency

Although agroforestry is a relatively new scientific field, 

indigenous agroforestry systems have been cultivated for 

centuries—if not millennia—in much of the world, including 

in North America, the Pacific Islands, and the Caribbean (Clark 

and Nicholas 2013, Clarke and Thaman 1993, Ffolliott 1998, 

Lepofsky 2009, Smith 1929) (fig. 5.2). There is much to be 

learned from the adaptation strategies of indigenous peoples 

that have been developed in response to environmental changes 

over millennia and not just decades (Wildcat 2014). The longterm presence of agroforestry in much of the world is indicative 

of its resilience to extremes in temperature, precipitation, and 

storm wind, all of which are projected to become more frequent 

(Australian Bureau of Meteorology and CSIRO 2011, 2014; 

Keener et al. 2012; Kirilenko and Sedjo 2007).

Traditional indigenous multistrata agroforestry systems are 

models for sustainable agroecosystems (Kumar and Nair 2007, 

Soemarwoto 1987, Torquebiau 1992). Indigenous multistrata 

homegardens, which provide family food security throughout 

the tropics, are considered to be “the epitome of sustainability” 

(Kumar and Nair 2004). These multistrata systems that include 

a multitude of crop species and cultivars with varying tolerances to drought, waterlogging, wind, salt spray, and other climatic 

variables increase the resilience of their overall productivity 

when impacted by episodic environmental stressors (Barnett 

2011). Crop and cultivar selection is crucial for the ability 

of the practice to tolerate sporadic environmental extremes. 

For example, in coastal buffer agroforestry for windbreak, 

erosion control, and food production, plants are chosen for their 

high tolerance to salt spray and storm surges (Wilkinson and 

Elevitch 2000).

After European/Western contact, colonization destroyed many 

of these traditional agroforestry systems, or they became 

neglected in favor of plantation-type agriculture in a process 

known as “agrodeforestation” (Thaman 1992). Today, up to 

90 percent of food consumed in the previously self-sufficient 

island states of the Pacific and Caribbean is imported (FAO 

Figure 5.2. Indigenous agroforestry systems have a long history in North America, the Pacific Islands, and the Caribbean. (A) A 

multistory cropping agroforestry system in Palau. (Photo by J.B. Friday, University of Hawaii). (B) Agroforestry system with coconut and taro on an atoll in the Pacific Islands. (Photo by John Quidachay, USDA Forest Service). (C) Ron Reed of the Karuk Food 

Crew collects gooseberries. (Photo by Colleen Rossier, University of California, Davis). (D) A member of the Alabama-Coushatta Tribe 

harvests longleaf pine needles for basket weaving. (Photo by Beverly Moseley, USDA Natural Resources Conservation Service).

A B

C D
Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions 79

2005). Loss of indigenous systems has led to environmental 

degradation and food insecurity for many developing small 

island states (Pelling and Uitto 2001). Residents of some low 

islands of the Pacific are some of the first climate change 

refugees in the world due to rising sea levels and amplified 

storm surges (Park 2011).

These threats, combined with rising awareness of the expected 

climate-related stressors, have resulted in renewed interest in 

protecting, expanding, and reestablishing agroforestry systems 

modeled after local indigenous systems (fig. 5.3). Trosper 

and Parrotta (2012: 1) wrote, “The role of traditional knowledge—and the bio-cultural diversity it sustains—is increasingly 

recognized as important by decision makers, conservation and 

development organizations, and the scientific community.” 

Historical forced displacement, land seizure/cessions, and 

migration of indigenous people combined with social, economic, and land-use alterations with modernization have led to 

losses in traditional knowledge of systems and cultivars (Clarke 

and Thaman 1993, Falanruw 2009). Conversely, the remnants 

of traditional systems—and even virtually intact indigenous 

systems—that still exist represent a widespread and diverse 

reservoir of experience, species, and knowledge from which to 

draw in building adaptive responses to climate change.

Affirmation of traditional practices, based on cultural aesthetics 

combined with scientific and economic validation of their 

productivity and practicality as an adaptation strategy, will help 

raise awareness and appreciation by producers, researchers, 

policymakers, and the general public. This increased awareness 

and appreciation will, in turn, lead to retention and use of traditional knowledge with due acknowledgment of its indigenous 

origins (Williams and Hardison 2013) as a viable and important 

component of climate change adaptation.

Agroforestry Practices, American Indians, and 

Climate Change

American Indians across North America have been using and 

adapting traditional management practices to maintain and 

enhance food, fiber, and medicinal resources over millennia for 

their livelihoods and economies (Anderson and Parker 2009, 

Cleveland et al. 1995, Parlee et al. 2006). Many tribal programs 

and communities are implementing agroforestry practices to 

achieve resource objectives that integrate local values. These 

practices are locally adaptive and responsive to particular 

agricultural, range, and forestry systems that reflect tribal 

traditions (Mondou 1998).

American Indian land tenure arrangements are diverse. Tribal 

trust lands broadly include an array of designations ranging 

from reservations, rancherias, and individual allotments. Tribes 

also hold lands in fee, lease private property, and, in turn, lease 

tribal lands to nontribal entities, or they have arrangements 

and agreements to work on public lands within their ancestral 

territory. During early European settlement and development, 

Figure 5.3. Timeline depicting influences on indigenous agroforestry systems and their adaptive responses to change.
80 Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions

many tribes were displaced, relocated, or moved out of their 

ancestral territory. Engaging in agroforestry practices can foster 

the integration of traditional values with modern resource 

management on tribal lands (Mondou 1998, Teel and Buck 

1998). As Norton-Smith et al. (2016) indicate, adaptation 

methods may include initiatives that foster cultural identity and 

connection to place.

Agroforestry land management practices implemented by tribes 

and tribal members include forest farming, alley cropping, 

riparian forest buffers, windbreaks, and silvopasture. Other 

land management practices implemented by tribes and tribal 

members include forest/woodland grazing; fuelwood, biofuel, 

and fiber production from agricultural land, forest land, and 

rangeland; wild harvest (pine nuts, acorns, berries, mushroom, 

etc.); edible landscaping; intercrops as beneficial insect refuges; 

and groundwater and irrigation drainwater management 

(Bainbridge 1995, Rossier and Lake 2014). Tribes or tribal 

individuals use these practices to produce traditional foods, fibers, basketry/art materials, and medicinal plants or to maintain 

traditional customs and practices. These practices are often at 

a small scale, however, when compared with tribal work on 

conventional forestry, range, or agricultural operations. The 

distribution of many traditional food, fiber, and other species 

is shifting as the climate changes, accelerating the complexity 

of access and making traditional subsistence harvesting and 

storage practices more challenging (Norton-Smith et al. 2016). 

Adaptation strategies should recognize the cultural importance 

of these species as well as their political context (Lynn et al. 

2013). This context is important when considering agroforestry 

as an adaptation strategy as well.

Tribal Examples of Agroforestry

Many tribes across the United States have established a range 

of different agroforestry systems that integrate indigenous 

knowledge and stewardship practices with contemporary restoration and economic development opportunities (Cleveland 

et al. 1995; for tribal agriculture, see Mondou 1998; Rossier 

and Lake 2014). (Several regional examples are provided in 

boxes 5.1 to 5.4.) Peer-reviewed literature that describes these 

systems, particularly in the context of climate change, is sparse. 

As a result, these examples outline a limited set of known 

examples of agroforestry systems based on the information that 

is available. Tribal agroforestry pilot projects that started in 

the past 20 years could be evaluated for the potential success 

as applicable climate change adaptation strategies (Luna 2000, 

Rossier and Lake 2014, Mondou 1998).

In addition, many tribes across the United States are engaged 

in nursery greenhouse projects to support restoration of 

culturally valued plants (Dumroese et al. 2009). For example, 

Blackfeet Community College has a tribal nursery greenhouse 

project in which horticultural trials with traditionally used 

native plants species were conducted. More than 50 native 

plants were propagated for restoration and cultural education 

activities, especially for activities related to history and 

language associated with native plants (Luna 2000). Some of 

this restoration work is designed to create systems that include 

agroforestry practices.

Box 5.1. Winnebago Reservation 

in Nebraska

Members of the Winnebago Reservation in Nebraska 

started a project to integrate forestry and agricultural 

management to meet local tribal food, land restoration, 

and soil conservation needs. They implemented a 

multicropping system by converting some commercial 

agricultural land into crops of traditional food species 

integrated with cultivars (Szymanski and Colletti 1999). 

They planted clover, corn, and soybeans between 

black walnut trees in an alley cropping system. They 

reforested areas between fields creating windbreaks and 

riparian forest buffers along streams. These efforts also 

were intended to improve wildlife habitat (Szymanski et 

al. 1998). The goal of the multicropping system was to 

produce shorter rotation cover crops and annual food 

crops and to foster longer lived species that provide 

food and wildlife habitat. No published research on 

the outcomes of this project was located nor was a 

response received from the tribe when an effort was 

made to contact them.

Box 5.2. Mississippi Band of the 

Choctaw

A cooperative effort among the Mississippi Band of 

the Choctaw Tribe; the U.S. Department of Agriculture, 

Natural Resources Conservation Service; and others 

in Neshoba County, MS, sought to restore riparian and 

wetland systems to support cultural basketry traditions 

(Luna 2000). The tribal greenhouse was used for 

propagating plants that were of cultural and ecological 

importance. Focal plant species included Nutall oak 

(Quercus texana), mockernut hickory (Carya tomentosa), 

and switchcane (Arundinaria gigantea). Switchcane is 

one of the largest native grasses in North America, and 

the fiber is used in Choctaw basketry. The production of 

these baskets provides income for the tribe. Restored 

riparian and wetland areas with switchcane patches are 

harvested for use in traditional tribal basketry.
Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions 81

Box 5.3. Seminole Tribe of Florida

The Seminole Tribe of Florida is carrying out silvopasture 

and other agroforestry practices in several States of 

their ancestral territory on tribal reservation and other 

trust lands and also on purchased private lands. The 

Seminole historically raised cattle and integrated range 

management with traditional burning of forests and 

grasslands (Sievers et al. 1985). The tribal silvopasture 

program integrates cattle range improvement with 

prescribed fire and other agricultural and farming needs 

of the tribal community. The tribe is also leasing lands, 

implementing agroforestry and restoration practices, 

and generating revenue from land leasing for farming 

and hunting.

Box 5.4. Karuk, Yurok, and Hoopa 

Valley Tribes in California

In northern California, the Karuk, Yurok, and Hoopa Valley Tribes are integrating traditional forest management 

with agroforestry practices to reduce hazardous fuel 

loads, reintroduce fire, and enhance traditional foods 

(Rossier and Lake 2014). Tribes historically managed 

Douglas-fir-tanoak forests with fire to promote access 

for gathering different food resources. Fire reduces 

understory vegetation, improves tribal gatherer mobility, 

improves nutrient cycling, reduces nut and other insect 

pests, and enhances food quantity and quality (Anderson 1994). The benefits of agroforestry practices on 

valued tribal food and basketry plants are being studied 

in collaboration with Federal agencies, watershed and 

fire safe councils, and academic researchers. This work 

has the potential for application on National Forest 

System lands.

Projected Impacts of Climate Change on Tribally 

Valued Resources and Tribal Agroforestry Practices

Ecological disturbances, such as flooding, drought, fire, and 

extreme weather events (e.g. temperatures) affect agroforestry 

practices and resources used for a range of tribal purposes 

(Cleveland et al. 1995, Mondou 1998, Voggesser et al. 2013). 

These disturbances directly and indirectly affect ecosystem 

goods and services and valued habitats and resources such as 

traditional and cultivated food crops; basketry materials/fiber 

resources; ranching, farming, and hunting practices; wildlife 

habitat quality that is of spiritual, cultural, and economic 

importance; public/tribal municipal water and air quality; and 

community recreational activities (Burger et al. 2008, Lynn 

et al. 2013). Downscale climate models and specific species 

climatic resilience studies have general application to tribes 

(Liverman and Merideth 2002, Vose et al. 2012).

The effects of climatic variability and climate change on 

American Indians and affiliated indigenous people and the 

Federal policies and authorities that are applicable are not 

well understood by resource managers and others working 

with tribes (Cordalis and Suagee 2008). A limited number of 

Federal policies and authorities pertain to tribal agroforestry 

and climate change. Currently, these polices address tribal 

agroforestry and climate change as separate issues, which 

may limit the use of indigenous agroforestry as an adaptive 

strategy for climate change. For instance, Section 105(a)(4) of 

AIARMA (1994) has implications for tribal agroforestry, but 

it lacks specific mention of climate change. Native Hawaiians 

and Pacific Islanders of U.S.-affiliated territories have other 

local authorities such as Act 234 (State of Hawaii 2007), which 

addresses climate change but does not specifically address 

Native Hawaiians or agroforestry.

Considerations for Tribal Agroforestry

Many indigenous and tribal communities desire land, resource 

management, and agroforestry management tools that provide 

access to and improve the quality of valued habitats necessary 

to perpetuate traditional customs and knowledge systems in their 

ancestral homelands (Jones 2000, Rossier and Lake 2014). The 

adoption of traditional stewardship methods and related tribal 

agroforestry practices by nonindigenous/nontribal entities may have 

benefits ecologically and for food and fiber production systems, 

but it can create other concerns or pose threats for indigenous/

tribal communities (Altieri and Nicholls 2013, Dixon et al. 

1994). The misappropriation of traditional knowledge and tribal 

agroforestry practices by nonindigenous resource managers 

or industry is a concern and sensitive issue (Williams and 

Hardison 2013). Many anthropologists documented historical 

tribal harvesting practices and uses of food, fiber, and medicinal plants (Moerman 1998), from which many commercial 

enterprises benefit without any direct compensation back to 

tribes as the original holders of that knowledge and practice 

(Tedder et al. 2002). Many agricultural systems benefit from 

cultivars that originate from tribal sources, yet no recognition 

of or compensation for this indigenous/tribal legacy is formalized (Thrupp 2000). Mondou (1998: 407–408) states—

Many Native American Indian farmers are striving to 

bring [traditional] farming back as an integral part of 

their respective culture by using modern technologies, 

while at same time trying to protect the folk variety 

seeds from mass marketing. With the advent of 

sophisticated biotechnologies and markets that are 
82 Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions

worldwide in scope, notwithstanding intellectual 

property rights of the particular tribe, folk variety 

seeds of the indigenous people are in demand.

In addition, the commercial production, management, and wild 

harvesting of berries originates from tribal stewardship (Moore 

1994), but commercial harvesting interest has affected tribal 

gathering.

The formulation of Federal policies and authorities that protect 

traditional knowledge, stewardship methods, and agroforestry 

practices consequently are limited. The Cultural and Heritage 

Cooperation Authority authorized in the Food, Conservation, 

and Energy Act of 2008 (also known as the 2008 Farm Bill) 

provides specific authority to the USDA Forest Service to 

protect tribal information about resources, cultural items, uses, 

or activities that have a traditional and cultural purpose from 

release under the Freedom of Information Act (CHCA 2008). 

Desai (2007) provides international examples for protecting 

traditional knowledge. Furthermore, many indigenous and tribal governments and community members will want assurances 

that their knowledge, traditional customs, and agroforestry 

practices will not be co-opted by nontribal members without 

permission or will not be inappropriately applied, which could 

result in the further disenfranchisement, marginalization, or exclusion from resource management, food and fiber production, 

and scientific research (Williams and Hardison 2013). Research 

can examine and provide evaluation for understanding at which 

scale or landscape condition indigenous and tribal agroforestry 

practices would increase the resilience of agricultural, range, 

and forestry production systems against changing conditions.

U.S.-Affiliated Tropical Islands

The U.S.-affiliated tropical islands of the Pacific and Caribbean 

comprise hundreds of islands of varying sizes, elevations, 

climates, peoples, and histories. Agroforestry was, and on 

many islands is still, the predominant form of agriculture, 

using species and techniques introduced and developed before 

contact with European/Western culture. On various islands, 

these techniques include shoreline plantings and windbreaks, 

intensive mulching, shifting agriculture followed by forest 

fallow with varying degrees of enhancement, and multistory 

agroforestry (see the section on Hawaii and the U.S.-Affiliated 

Pacific Islands in appendix A). Colonization and subsequent 

cultural change have affected land tenure; shifted subsistence 

agroforestry toward cash economies and monocrop agriculture; 

and interrupted the transmission of traditional ecological 

knowledge, including agroforestry.

Climate change impacts on these islands, which vary depending 

on the region and local topography, include drought, increased 

storm intensity (wind and rainfall), sea level rise and coastal 

erosion, and salinization of groundwater. High sea levels have 

been especially pronounced in the western Pacific in recent 

years because of prevailing La Niña conditions, with coastal 

erosion and groundwater salinization being exacerbated on 

atolls by development impacts (Keener et al. 2012; Hawaii and 

the U.S.-Affiliated Pacific Islands in appendix A). Current-day 

island experiences of storms, inundation events, drought, and 

degradation of freshwater resources heighten public awareness 

and anticipation of climate change in the Pacific and Caribbean. 

These experiences seem to accelerate Pacific migration trends 

(already occurring because of aspirations for education, health 

care, and employment) from atolls to “high” (volcanic) islands 

and from remote islands to U.S. domestic areas (Hezel 2001). 

At the same time, communities and governments assert the 

desire for “future generations living productive lives on these 

islands” despite climate change, prioritizing the need for 

adaptation of agricultural policies and practices (RMI 2011).

Practitioners of agroforestry in the islands are diverse and 

include—

• Indigenous Pacific people who follow practices passed down 

to them by centuries of common tradition and by guarded 

family secrets, as in the case of prestige crops like yams 

in Pohnpei (Raynor and Fownes 1993). Their traditional 

ecological knowledge encompasses practices that effectively 

conserve soil and water and provide nutritious subsistence 

produce. A serious constraint to the continuation of these 

systems has been the interruption of passing traditional 

ecological knowledge to younger generations. With cultural 

change, family members who move away, focus on paid 

employment, or do not value the old ways, do not acquire the 

knowledge of their elders.

• Pacific Island residents practicing agroforestry with less 

benefit of traditional ecological knowledge. This group of 

practitioners includes younger generations; farmers affected 

by new pests or diseases that are unknown in traditional systems; inter-island migrants, who now practice on a different 

island (with different soils or climate); and migrants and 

contract laborers (primarily from Asia), who bring their own 

cultural practices and crop preferences. 

• Small- and large-acreage landowners who grow coffee and 

other row or orchard crops with overstory shade (coffee and 

cacao) or windbreaks, particularly in the Caribbean, Hawaii, 

and Guam.

• Ranchers who incorporate agroforestry techniques (windbreaks, shade trees, living fences, alley cropping, and/or 

protein banks), particularly in the Caribbean, Hawaii, and 

Mariana Islands.

• Families of any description who have homegardens, 

including tree and nontree crops.
Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions 83

Learning Networks

Changes in hydrology, variable weather conditions, and climate 

change and the introduction of invasive plants, insects, pests, 

and diseases constrain the success of traditional agroforestry 

systems. The variety of island ecosystems, indigenous systems, 

and species provides an opportunity for one island with changing conditions to look to another island for potential solutions. 

Pacific Island forestry agencies (USDA Forest Service grantees) welcome USDA technical assistance, even for traditional 

systems, to cope with new and unfamiliar weather/climate 

conditions and pests, as long as the advice and advisor respect 

the local context and knowledge (Friday 2011). In the Caribbean, associations for shade coffee and agroecology actively 

promote and support agroforestry, in collaboration with the 

USDA Natural Resources Conservation Service, U.S. Fish and 

Wildlife Service, university agricultural extension services, 

local governmental agencies, and environmental organizations 

that seek benefits for biodiversity and watersheds.

Food Security, Ethnoagrobotany, and Cultural Pride

In the Pacific, a constraint to sustaining subsistence agroforestry and expanding it into the commercial realm has been the 

relative inconvenience of agroforestry products to consumers. 

They tend to be perishable, unfamiliar to new residents, and/

or not marketed through commercial channels (Hollyer 2014). 

The counterbalancing opportunity is increasing awareness of 

the nutritional value of fresh, local island produce, especially 

starches with high fiber and vitamin content (e.g., breadfruit, 

taro, yam, sweet potato) relative to processed carbohydrates 

(white rice and flour), and of traditional or introduced species 

and cultivars with high vitamin content (e.g., the Karat banana) 

(Englberger and Lorens 2004). Campaigns for food security 

have tapped cultural pride, as with the Waianae Diet (Shintani 

et al. 1994) and documentation of ethnoagrobotanical heritage 

(Balick 2009). Initiatives have included policies favoring local 

food, promotional festivals, and projects in food processing and 

marketing improvements. Demand and markets for subsistence 

products vary by island and time period. The Caribbean 

likewise has a wealth of tropical fruits and special varieties 

(e.g., the West Indian avocado) through homegardens and local 

markets that can enrich diets.

Economic Valuation

Another constraint to the use of agroforestry on the islands 

has been a historic focus by governments on cash crops and 

“modern” systems. This constraint in part stems from insufficient awareness and appreciation of traditional agroforestry. 

Many tropical agroforestry systems are still partially or wholly 

for subsistence use and their products are seldom included in 

agricultural and economic statistics. Past colonial or government decisions have resulted in land-use conversions to pasture 

and monocrop plantations (notably sugar and pineapple) and 

in a lack of institutional and extension support to validate and 

expand agroforestry. Valuation of agroforestry products, in 

terms of cash value of products (including import substitution) 

and per-acre values of agroforestry as a land use, provides an 

opportunity to increase recognition of agroforestry, leading to 

more supportive policies (ADB 2005; Drew et al. 2004, 2005).

Economic Viability at Farm Level

Coffee grown under partial tree canopy shade (considered a 

multistory agroforestry practice) was once common in Puerto 

Rico until government subsidies and technical assistance promoted a transition to higher yielding, full-sun (nonagroforestry) 

systems. Coffee production then encountered labor constraints, 

low incomes, and catastrophic hurricanes, resulting in marked 

declines between 1982 and 2007. Problems of full-sun systems 

include shortened life span of coffee shrubs, high erosion rates, 

water-quality problems, and destruction of habitat for wildlife 

species. Growers’ preference for shaded coffee systems 

provides an opportunity to return to agroforestry practices that 

afford more biodiversity and watershed environmental services, 

especially if incentives and support are provided for shade 

coffee as they were for sun coffee (Borkhataria et al. 2012). 

Likewise, some coffee farmers in Hawaii prefer shade coffee 

because of its more pleasant work environment and wildlife 

habitat (Elevitch et al. 2009). Many of the U.S.-affiliated 

islands have important tourism industries that provide opportunities for additional farm income through tourist experiences 

with coffee and other exotic agroforestry products.

Land-Use Planning and Land Tenure

Migration and land tenure sometimes affect agroforestry in the 

context of the whole-island landscape. In the Pacific, as people 

move from distant to central islands or from coasts to interiors 

(because of climate change impacts or for other reasons), they 

seek land for food production. Sometimes native primary 

forest is converted to agroforest (FSM 2010), and sometimes 

agroforestry is intensified by using fewer trees (ASCC 2010). 

Where the practice of agroforestry or the planting of certain 

species signifies a claim to the land, that tradition thus encourages clearing native forest for agroforest. Changes in historic 

land tenure systems have resulted in weaker community and 

familial regulation of resources, often leading to exploitation 

and overuse (Falanruw 1992). The opportunities, therefore, are 

for governments to encourage agroforestry development in the 

most appropriate locations available—for example, by considering slope and erodibility when regulating land distribution 

and allowable uses (FSM 2010, KIRMA 2003), siting road 

development to enable access to suitable lands (Ramsay et 

al. 2013), providing grassland or secondary vegetation areas 

to migrants or other residents for agroforest development 
84 Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions

(FSM 2010), reviving traditional conservation authorities, and 

providing extension support to influence choices (Shed 2012). 

In the Caribbean, historical changes in land tenure, industrialization, and recent urbanization disrupted family farming. Now, 

former agricultural land reverting to secondary forest in Puerto 

Rico and the U.S. Virgin Islands (Brandeis and Turner 2013a, 

2013b) may provide an opportunity to expand agroforestry land 

uses, although the fertility of much of that land is constrained 

by soil degradation (Lugo and Helmer 2004).

Conclusions

Farmers, ranchers, tribes, and other land managers are the 

gatekeepers to realizing agroforestry’s potential for climate 

mitigation and adaptation. Because agroforestry is primarily 

conducted on private lands, human dimensions must be considered in the development of policies, programs, and outreach 

efforts. Potential agroforestry adopters are diverse—they 

differ in respect to their needs, types and conditions of their 

resources, social and cultural backgrounds, and the landscapes 

in which they operate. Agroforestry practices are also site 

specific, modified to suit the physical resources and ecology 

of the site. As a result, no one route will effectively encourage 

agroforestry adoption. Different strategies are needed to 

address the different challenges that land managers face in 

managing their operations and resources under climate change. 

Research on human dimensions in agriculture and resource 

management provides a beginning foundation on which to 

effectively advance agroforestry outreach and adoption. 

Increased educational opportunities, policy support, and 

partnerships may also encourage agroforestry implementation. 

Renewed interest in protecting, expanding, and reestablishing 

agroforestry systems modeled after local indigenous systems 

has emerged because of the resilience of those systems to 

climate change threats. The adoption of these traditional 

stewardship methods should be done with care to protect and 

respect the autonomy of tribal and indigenous sovereignty.

Key Findings

• Factors influencing agroforestry adoption are similar to 

the factors that influence other conservation practices and, 

as such, agroforestry programs can build off information 

generated through research in these other areas.

• The various demographic groups in agriculture (e.g., small 

farms, tribes, limited-resource producers) have diverse motives and characteristics that can contribute to the adoption 

of agroforestry. Targeting adoption strategies based on these 

motivations and characteristics may enhance adoption. 

• Addressing extreme weather and climate change impacts 

is but one of many reasons that landowners may adopt 

agroforestry practices.

• Common barriers to agroforestry adoption include implementation costs, labor requirements, longer timeframe for return 

on investment, uncertain land tenure, lack of information, 

and increased complexity. 

• Traditional agroforestry systems of the United States and the 

U.S.-affiliated islands are important to indigenous populations, 

particularly for food security and cultural resources under 

the uncertainty of climate change. These time-tested models 

can inform solutions for building modern-day resilient 

agroecosystems, but few Federal policies specifically 

support indigenous agroforestry systems.

• Support for agroforestry adoption exists through various 

policies, partnerships, educational and technical assistance 

opportunities, and incentives and other financial assistance 

programs.

Key Information Needs

• A greater understanding of land managers’ perceptions of 

climatic variability and change and how it influences their 

decisionmaking, particularly concerning use of conservation 

practices (including agroforestry practices). 

• More information regarding how agroforestry can fit into 

different types and scales of agricultural operations and 

marketing systems, including financial and labor requirements 

and economic values.

• The identification of the types of technical support and 

educational opportunities that are most effective at encouraging agroforestry adoption. 

• A broader understanding of the additional support tribes and 

U.S.-affiliated island communities will require for adapting 

to current and anticipated climate change impacts. 

• Better documentation of historical and current tribal and 

island agroforestry practices, with an emphasis on how these 

practices can be framed as or adapted for agroforestry land 

management.

• Evaluations on the resiliency of tribal and island agroforestry 

systems to disturbances, including assessments of threats 

and opportunities to enhance sustainability under climate 

change.

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90 Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions
Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions 91

Chapter 6

Agroforestry Resources

W. Keith Moser and Gary Bentrup

W. Keith Moser is a research forester, U.S. Department of Agriculture (USDA), Forest Service, Rocky 

Mountain Research Station; Gary Bentrup is a research landscape planner, USDA Forest Service, USDA 

National Agroforestry Center.

Agroforestry has potential to serve as a climate change management option for building resilient and profitable agricultural 

operations and landscapes. Realizing this potential requires 

identifying the opportunities and tradeoffs that exist in each situation and designing an agroforestry practice that achieves the 

desired balance among them. The decisionmaking process must 

incorporate many considerations, not only at the field scale 

but also at the larger scales of farm, landscape, and watershed, 

while taking into account climate variability and change.

Resources for planning, designing, and implementing agroforestry systems can provide assistance in this process. Important 

resources for these tasks include decision-support tools and 

conservation programs that provide technical and financial 

assistance to interested landowners. This chapter presents 

available resources in both of these categories and identifies 

gaps in the suite of tools.

Decision-Support Tools

The application of agroforestry can be greatly enhanced 

through the use of decision-support tools, which are any technology or resource that can be used to help integrate diverse 

sets of information (Ellis et al. 2004). Information gathering 

and analysis tools already exist at the farm ownership level, 

the most notable being precision agriculture systems (Mulla 

2013). The focus of this section is on decision-support tools 

that assist implementation rather than tools that aid research in 

agroforestry science. Crucial differences exist between research 

tools and planning-and-design tools. Researchers generally 

seek answers to “Why?” whereas practitioners and landowners 

need answers to “What?” “Where?” and “How?” Useful 

decision-support tools for implementation should—

1. Minimize expenses.

2. Reduce dead ends.

3. Reduce anxiety of landowners and practitioners.

4. Accelerate necessary decisionmaking.

Agroforestry systems in the United States are applied in 

diverse geographic, environmental, and institutional contexts. 

In addition, each landowner has a unique set of conditions that 

will dictate different questions that the decision-support tools 

need to answer (Arbuckle et al. 2009). In light of each unique 

situation, practitioners and landowners will need to rely on 

a suite of tools throughout the planning and implementation 

process (Ellis et al. 2004).

Table 6.1 lists a broad cross-section of tools to support 

planning, design, and management of agroforestry systems. 

Although not an all-encompassing list, it illustrates the range 

and type of tools that are available. Some of these tools are 

specifically developed for agroforestry systems and others 

come from different disciplines but can be used effectively in 

agroforestry applications. Not every tool has a climate change 

focus, but most can help the user address the potential impacts 

of a changing climate and possible responses.

Table 6.1. Examples of decision-support tools to support planning, design, and management of agroforestry systems.

Decision-support tool Tool type Focus Description End user Reference/link

Agroforestree Database Database Biophysical Provides information on the 

management, use, and ecology of tree 

and shrub species used in agroforestry.

Practitioners, 

landowners, 

researchers

Orwa et al. (2009) http://

www.worldagroforestry.

org/resources/databases/

agroforestree

Agroforestry Species 

Switchboard 1.0

Database Biophysical Documents the presence of more than 

22,000 plant species in 13 Webbased databases and, when available, 

provides hyperlinks to information on 

the selected species.

Practitioners, 

landowners, 

researchers

Kindt et al. (2013) http://

www.worldagroforestry.org/

products/switchboard/
92 Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions

Table 6.1. Examples of decision-support tools to support planning, design, and management of agroforestry systems (continued).

Decision-support tool Tool type Focus Description End user Reference/link

Forestry Compendium Database Biophysical, 

economic, 

social

Offers a compilation of knowledge 

on forestry, agroforestry, and tree 

plantations, including decisionmaking 

information for tree management.

Practitioners, 

researchers

http://www.cabi.org/fc/ 

Agroforestry Suitability 

Assessments

GIS Biophysical, 

economic

Provides instruction for developing 

GIS-based suitability assessments for 

agroforestry.

Practitioners Bentrup and Leininger (2002)

Target Regions for 

Silvoarable Agroforestry 

in Europe

GIS Biophysical Identifies regions where productive 

growth of trees in agroforestry systems 

could be expected and where these 

systems could reduce soil erosion and 

nitrate leaching and increase landscape 

diversity.

Practitioners, 

researchers, 

policymakers

Reisner et al. (2007)

Agroforestry 

Development 

Production Tool

Model Biophysical, 

economic, 

social

Helps assess many levels of new 

agroforestry endeavors, including 

environmental, social, and economic 

considerations; labor; and cashflow 

planning.

Practitioners, 

landowners

http://agroforestry.ubcfarm.

ubc.ca/agroforestryproduction-development-tool/

COMET-FarmTM Model Biophysical Enables farmers and ranchers to 

estimate carbon sequestration and 

GHG emissions related to crop and 

livestock production and on-farm 

energy use.

Practitioners, 

landowners

http://comet-farm.com

HOLOS Farm 

Greenhouse Gas 

Calculator

Model Biophysical Estimates GHG emissions based on 

information entered for individual farms 

(calibrated for Canada) using wholefarm modeling software program.

Practitioners, 

landowners

http://www.agr.gc.ca/holosghg

FALLOW (Forest, 

Agroforest, LowValue Landscape or 

Wasteland)

Model and 

GIS

Biophysical Evaluates impacts of shifting cultivation 

and fallow rotations at a landscape 

scale, evaluating transitions in soil 

fertility, crop productivity, biodiversity, 

and carbon stocks.

Practitioners, 

researchers

http://worldagroforestrycentre.

org/regions/southeast_asia/

resources/fallow-forestagroforest-low-valuelandscape-or-wasteland

AgBufferBuilder Hybrid GIS 

and model

Biophysical Designs buffers around agricultural 

fields using terrain analysis to account 

for spatially nonuniform runoff.

Practitioners, 

researchers

http://nac.unl.edu/tools/

AgBufferBuilder.htm

Water Erosion 

Prediction Project 

(WEPP)

Model Biophysical Predicts soil erosion and the effects of 

conservation practices on soil erosion.

Practitioners, 

researchers

http://www.ars.usda.

gov/Research/docs.

htm?docid=10621

Riparian Restoration 

to Promote Climate 

Change Resilience Tool

Hybrid GIS 

and model

Biophysical Identifies areas in the riparian zone that 

would benefit most from increased 

shading produced by planting trees.

Practitioners, 

landowners

http://applcc.org/plan-design/

gis-planning/gis-toolsresources/riparian-restorationdecision-support-tool-1

Economic Budgeting for 

Agroforestry Practices

Model Economic Provides guidance for developing 

agroforestry enterprise budgets.

Practitioners, 

landowners

http://www.

centerforagroforestry.org/

pubs/economichandbook.pdf

Simulation Tool to 

Assess Economic 

Impacts of Agroforestry 

Practices

Model (Excel 

based)

Economic Evaluates the economic impacts of 

installing riparian forest buffers and 

windbreaks for crop, building, and road 

protection.

Practitioners, 

landowners

http://www.wbvecan.ca/

anglais/coutspdf.html

Farm-SAFE Model (Excel 

based)

Economic Compares arable, forestry and 

silvoarable systems across four areas 

of a farm in order to determine the 

feasibility of silvoarable systems.

Practitioners, 

landowners, 

researchers

Graves et al. (2011) https://

www.agforward.eu/index.php/

en/web-application-of-yieldsafe-and-farm-safe-models.

html

Elderberry Financial 

Decision Support Tool

Model (Excel 

based)

Economic Assists with establishment and 

management decisions.

Practitioners, 

landowners

http://www.

centerforagroforestry.org/

profit/elderberryfinance.php

Black Walnut Financial 

Model

Model (Excel 

based)

Economic Assists with establishment and 

management decisions.

Practitioners, 

landowners

http://www.

centerforagroforestry.org/

profit/walnutfinancialmodel.

php

Windbreak Economic 

Model

Model (Excel 

based)

Economic Estimates long-term financial benefits 

of windbreaks on crop yields.

Practitioners, 

landowners

http://www.

centerforagroforestry.org/

profit/#budget
Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions 93

Table 6.1. Examples of decision-support tools to support planning, design, and management of agroforestry systems (continued).

Decision-support tool Tool type Focus Description End user Reference/link

Midwest Hazelnut 

Enterprise Budget Tool

Model (Excel 

based)

Economic Assists with establishment and 

management decisions.

Practitioners, 

landowners

http://midwesthazelnuts.org/ 

Buffer$ Model (Excel 

based)

Economic Analyzes cost-benefits of implementing 

buffers compared with traditional crops.

Practitioners, 

landowners

http://nac.unl.edu/tools/

buffer$.htm

Snow Fence CostBenefit Web ToolModel Economic Calculates what transportation 

agencies can pay landowners to 

establish a living snow fence to reduce 

snow and blowing snow to highways.

Practitioners, 

landowners

http://snowcontroltools.umn.

edu/#!/calculator

CanVis 3.0 Visual 

Simulation Kit

Model Social Simulates agroforestry practices with 

2-D image-editing tool.

Practitioners, 

landowners

http://nac.unl.edu/simulation/

index.htm

Agroecological 

Knowledge Toolkit 

(AKT5)

KBS Biophysical, 

economic, 

social

Stores, manipulates, and analyzes a 

variety of information and knowledge 

on agroforestry agroecological systems.

Practitioners, 

researchers

http://akt.bangor.ac.uk/ 

Handbook for 

Agroforestry Planning 

and Design

Other: 

handbook

Biophysical, 

economic, 

social

Assist in the planning and design of 

agroforestry practices.

Practitioners, 

landowners

http://www.

centerforagroforestry.org/pubs/

training/HandbookP&D13.pdf

Agroforestry Tech Notes Other: 

technical 

note series

Biophysical, 

economic, 

social

Provides agroforestry information in a 

useful “how to” format.

Practitioners, 

landowners

http://nac.unl.edu/

publications/agroforestrynotes.

htm

Conservation Buffers 

Handbook

Other: 

handbook

Biophysical, 

economic, 

social

Provides design guidelines for buffers 

and other linear vegetative practices 

based on a synthesis of more than 

1,400 research publications.

Practitioners, 

landowners

http://nac.unl.edu/buffers/

index.html

Silvopasture: 

Establishment and 

Management Principles 

for Pine Forests in the 

Southeastern United 

States

Other: 

handbook

Biophysical, 

economic, 

social

Assist in managing pine silvopasture 

system in the Southeastern United 

States.

Practitioners, 

landowners

http://www.silvopasture.org/ 

Profitable Farms and 

Woodlands: A Practical 

Guide in Agroforestry 

Other: 

handbook

Biophysical, 

economic, 

social

Depicts step-by-step methods and 

principles on developing agroforestry 

practices for farmers and woodland 

owners.

Practitioners, 

landowners

http://nac.unl.edu/documents/

morepublications/profitable_

farms.pdf

USDA PLANTS Other: Web 

site (online 

database)

Biophysical, 

economic

Provides botanical information, images, 

and links on plants in the United States, 

including crops and invasive species.

Practitioners, 

landowners

http://plants.usda.gov/java/ 

Forest Farming 

eXtension Community 

of Practice

Other: Web 

site

Biophysical, 

economic, 

social

Consolidates resources on forest 

farming and offers a portal for 

landowners to ask questions of 

experts.

Practitioners, 

landowners

http://www.extension.org/

forest_farming

CropScape Other: Web 

site

Biophysical, 

economic

Provides a view of the USDA Cropland 

Data Layer for checking the type of 

crop grown in each field across the 

contiguous United States from 1997 to 

the present and a sequence of views 

that show how the distribution of crops 

has shifted over time.

Practitioners, 

landowners, 

researchers

http://nassgeodata.gmu.edu/

CropScape/

ClimateData.us Other: Web 

site

Biophysical, 

economic, 

social

Provides comparisons of projected 

changes in temperature and 

precipitation and of conditions by 

decade under a mitigation scenario 

(reduced emissions) and a highemissions scenario.

Practitioners, 

landowners, 

researchers

http://climatedata.us/ 

GHG = greenhouse gas. GIS = Geographic Information System. KBS = Knowledge-based system. USDA = U.S. Department of Agriculture.

Databases: Organize and facilitate the management and querying of large quantities of data and information.

GISs: Add a geographic or spatial component to a database; manage, manipulate, and analyze spatial data.

Models (mathematical): Represent real-world processes and predict outcomes based on input scenarios.

KBSs: Adopt artificial intelligence in the form of organizing, manipulating, and obtaining solutions, using knowledge in the form qualitative statements, expert rules (i.e., 

rules of thumb), and a computer language representation system for storing and manipulating knowledge.

Hybrid systems: Integrate two or more of the computer-based technologies listed in the table (e.g., GISs, KBSs, models) for more versatile, efficient, and comprehensive decision-support tools.

Other: Includes information resources such as Web sites and planning-and-design manuals.

Source: Adapted and updated from Ellis et al. (2004).
94 Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions

Conservation Programs

Voluntary conservation-based programs at the Federal, State, 

and local levels provide technical and financial assistance 

to landowners to develop conservation plans and install 

conservation practices. These programs address a number of 

farming- and ranching-related conservation issues, including 

drinking-water protection, agricultural-waste management, soil 

health improvement, enhancement of fish and wildlife habitat, 

and better forest management and wetland restoration. Because 

agroforestry can help solve these issues, conservation programs 

are used as a resource for implementing agroforestry practices, 

particularly riparian forest buffers and windbreaks.

Federal assistance for agroforestry is primarily administered 

through U.S. Department of Agriculture (USDA) agencies, 

such as the Farm Service Agency (FSA), Natural Resources 

Conservation Service (NRCS), Forest Service, and National 

Institute of Food and Agriculture (table 6.2). The USDA 

programs are authorized through farm bill legislation; the 

programs in table 6.2 are based on the 2014 Farm Bill and may 

be subject to change as the details of that policy are refined 

during the next few years. Other Federal assistance and funding 

for agroforestry are available through the USDI’s Fish and 

Wildlife Service. 

Depending on the details in each program, financial assistance 

for landowners can come in the form of cost sharing implementation costs, incentive and maintenance payments, and land 

use or rental payments. In return, landowners must commit 

to maintaining the practice for the length of the contract 

period. Within these Federal programs, resource professionals 

with NRCS, the Forest Service, State agencies, conservation 

districts, universities, and technical service providers provide 

technical assistance for planning and designing tree-based 

practices. These assistance programs collectively have been 

an important resource in implementing agroforestry on farms 

and ranches. Table 6.3 summarizes agroforestry practices 

applied using FSA and NRCS programs. Data from the other 

Federal programs are not tracked in a way to easily quantify the 

agroforestry practices implemented.

Table 6.3. Agroforestry practices applied during FY 2012 to 

FY 2015 using all FSA and NRCS conservation programs. 

Agroforestry practice applied Unit FY 2012–FY 2015

Windbreaks Kilometers 6,520

Riparian forest buffers Hectares 30,950

Alley cropping Hectares 110

Forest farming Hectares 12,475

Silvopasture Hectares 595

FSA = Farm Service Agency. FY = fiscal year. NRCS = Natural Resources Conservation Service.

Note: This table does not include agroforestry practices installed with other Federal or State programs or practices installed without assistance programs.

Source: USDA-NRCS (2016).

Table 6.2. Primary Federal conservation programs used for implementing agroforestry.

Conservation program Agency Description Eligible agroforestry practices

Conservation Technical 

Assistance (CTA)

USDA NRCS Technical assistance to clients to address opportunities, 

concerns, and problems related to the use of natural 

resources. 

Alley cropping, riparian forest 

buffer, windbreak, silvopasture, 

forest farming

Environmental Quality 

Incentives Program (EQIP)

USDA NRCS Financial assistance to promote agricultural production, forest 

management, and environmental quality as compatible goals. 

Alley cropping, riparian forest 

buffer, windbreak, silvopasture, 

forest farminga

Conservation Stewardship 

Program (CSP)

USDA NRCS Financial assistance to encourage producers to undertake 

additional conservation activities or to improve, maintain, and 

manage existing conservation activities. 

Alley cropping, riparian forest 

buffer, windbreak, silvopasture, 

forest farming

Conservation Reserve 

Program (CRP)

USDA FSA Financial assistance to help agricultural producers safeguard 

environmentally sensitive land and to convert marginal cropland 

to long-term conservation cover, either grass or trees. The 

land is bid into the program on a competitive basis and ranked 

based on environmental benefits and cost. 

Tree planting that can be used 

to support future agroforestry 

practices after contract period 

has expired

Conservation Reserve 

Enhancement Program 

(CREP)

USDA FSA Special financial initiative within CRP to address agricultural 

resource problems, targeting priority environmental needs and 

providing additional incentives for conservation. 

Riparian forest buffer, windbreak

Forest Stewardship Program 

(FSP)

USDA Forest 

Service

Technical assistance to nonindustrial private forest landowners 

to develop comprehensive, multiresource conservation plans 

for their forests. 

Alley cropping, riparian forest 

buffer, windbreak, silvopasture, 

forest farming

Sustainable Agriculture 

Research and Education 

(SARE) Program

USDA NIFA Competitive producer grants for landowners and practitioners 

who want to try new agroforestry enterprise concepts.

Alley cropping, riparian forest 

buffer, windbreak, silvopasture, 

forest farming, system research

Partners for Fish and Wildlife 

(PFW)

USFWS Financial and technical assistance to help conserve, protect, 

and enhance fish, wildlife, and plants and their habitats on 

private lands. 

Riparian forest buffer, tree 

planting

FSA = Farm Service Agency. NIFA = National Institute of Food and Agriculture. NRCS = Natural Resources Conservation Service. USDA = U.S. Department of Agriculture. USFWS = U.S. Fish and Wildlife Service.

a

 Practice availability will vary from State to State, depending on each State’s practice policies.
Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions 95

States

Many States also have agency-supported programs that may 

be used to establish agroforestry practices, even if the program 

objectives do not have an explicit agroforestry focus. These 

programs are tailored to each State’s conservation priorities and 

are too numerous to describe in this chapter. These programs, 

however, can be a resource for implementation because agroforestry can be used to support some State conservation goals. 

Although not a totally State-run program, the State of Washington Conservation Reserve Enhancement Program (CREP) 

is a joint Federal- and State-funded effort that restores riparian 

habitat for salmon. Since 1999, more than 445 hectares (1,100 

acres) of riparian forest buffers and other restoration measures 

have been implemented on the Tucannon River with CREP. 

This action has reduced summer mean water temperatures by 

about 5.5 oC, a valuable effect under a warming climate (Smith 

2012). Young Chinook salmon (Oncorhynchus tshawytscha) 

are now using areas of the river that were previously too warm 

for them; the number of returning Chinook adults rebounded 

from a low of 54 fish in 1995 to 1,239 in 2012 (Gallinat and 

Ross 2013).

Private or Other Nongovernmental Organizations

Numerous private organizations indirectly support agroforestry 

by offering grants, cost share, and equipment on loan for 

landowners who are improving wildlife habitat with timber 

stand improvement or by planting shrubs, trees, and forages. 

Examples of these private organizations are the National Fish 

and Wildlife Foundation (NFWF), the National Wild Turkey 

Federation, Quail Forever, Ducks Unlimited, and Pheasants 

Forever. For instance, NFWF is planning to invest $12.9 

million in the Chesapeake Bay watershed between 2013 and 

2025 to install 2400 kilometers (1,500 miles) of riparian forest 

buffers for water-quality and wildlife habitat improvement 

(NFWF 2012).

Challenges and Opportunities

Although tools are available for implementing agroforestry, 

challenges and needs persist as we improve existing tools and 

develop new ones to add to the suite of tools. These broad 

challenges include:

• Analytical capacity.

• Scalability.

• Comparison of alternatives.

• Usability.

Analytical Capacity

Unlike the extensive datasets that exist for agronomy and forestry 

in the United States, agroforestry has a less robust collection 

of data on which to develop decision-support tools and models 

(Ellis et al. 2004). The inherent flexibility of designing an agroforestry system or practice, although a highly desirable feature, 

can result in a number of potential agroforestry systems and 

combinations of plantings. The multiple possible combinations 

can create challenges for building tools and models capable 

of handling the diversity of options. As a consequence, basic 

models are often used to predict outcomes from agroforestry 

practices although these models can have high uncertainty and 

risk, especially due to our limited understanding of the impacts 

of climate change on agroforestry. Whereas climate change 

impacts on monoculture crops or simple livestock production 

systems can be reasonably predicted with process-based 

models, robust models for multifaceted agroforestry systems 

are not yet available (Luedeling et al. 2014). The challenge 

will be to enhance the analytical capacity of agroforestry tools 

for present-day decisionmaking and to refine those tools as 

additional information becomes available (see chapter 9).

Scalability

In the United States, agroforestry practices are implemented 

at the site scale by individual landowners who make decisions 

based on the benefits they desire, such as income diversification 

and soil protection. Among the agroforestry community, the 

expectation is that these individual agroforestry actions by 

numerous landowners will collectively lead to the benefits that 

society values, such as water-quality protection and food security, at a magnitude that will have impact. Many agroforestry 

decision-support tools have focused on the landowner scale 

(site, field, farm) because farmers and ranchers hold the key to 

agroforestry adoption and implementation. Tools at landscape 

and watershed scales, however, are also needed to help inform 

placement of agroforestry practices to more effectively achieve 

societal benefits (Tomer et al. 2009). Targeting tools that 

identify areas in the landscape where agroforestry practices 

can achieve multiple benefits simultaneously will be valuable 

in accomplishing landowner and societal goals (Reisner et al. 

2007). The challenge is to collect data at the appropriate scales 

and to build tools that can work across those scales.
96 Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions

Comparison of Alternatives

Decisionmakers often compare tradeoffs between alternative 

courses of action; therefore, effective decision-support tools 

need the capability to present the differences between the 

options (Ellis et al. 2004). By design, agroforestry can have numerous ecological, economic, and social effects, so the ability 

to compare these effects during decisionmaking is important. 

Placed within a larger context, agroforestry is just one option of 

many for transitioning to climate-smart agriculture (e.g., Delgado et al. 2011, FAO 2013). Many tools currently available for 

climate-smart agriculture focus on a single approach and do not 

facilitate cross-comparison among options (FAO 2013). Hence, 

the challenge is to develop tools that can compare tradeoffs 

among various climate-smart agricultural options at the scale of 

the decisionmaker (fig. 6.1).

Usability

The usability of a decision-support tool by end users may be 

the most important challenge to address because, if the tool is 

not used, the time and cost of developing the tool is generally 

wasted and the scientific information underlying the tool will 

not aid in decisionmaking (McCown 2002). To enhance the 

adoption and use of agroforestry tools, end users should be 

consulted in tool development from start to finish, ensuring the 

tools match their needs and capabilities (McIntosh et al. 2011). 

If end users are not involved in the process of developing these 

tools, the resulting tools may be too complicated, too narrowly 

focused, and too difficult to apply in many situations (Ellis et 

al. 2004). Another usability consideration, particularly with 

erratic weather and climate change, is accommodating users 

with different comfort levels regarding uncertainty and risk 

(Willows et al. 2003). Agroforestry tools will need to incorporate innovative ways to help users evaluate risk and uncertainty 

in a manner that fits their decisionmaking style (see Kujala et 

al. 2013, Peterson et al. 2003; see appendix B).

Figure 6.1. A conceptual framework for comparing climate-smart agriculture options for decisionmaking. This diagram illustrates 

the need for decision-support tools that enable comparison of options across a variety of ecological, economic, and social considerations. This framework ideally would allow for quantitative comparisons. The longer the buff-colored bar, the greater the positive 

result for that resource issue. (Basic scheme from Foley et al. 2005).
Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions 97

Opportunities

Decision-support tools are rarely standalone components but 

are used most effectively in a planning-and-design process to 

identify needs, develop plans, and compare tradeoffs. Technical 

assistance offered through conservation programs often 

provides a structured process in which to use decision-support 

tools to implement agroforestry. Among the opportunities to 

improve the delivery of this important service (Dosskey et al. 

2012), one of the greatest is to increase awareness of these 

conservation programs for implementing agroforestry through 

promotional materials, train-the-trainer programs, and agroforestry demonstration sites (Lassoie et al. 2000).

Another opportunity is to use the planning-and-design processes provided by conservation programs as a tool to assist in 

adaptive management. Adaptive management is a structured, 

iterative process of decisionmaking in the face of uncertainty, 

with the goal of reducing uncertainty over time via system 

monitoring (Howden et al. 2007). Adaptive management 

has the potential to reduce the risks of climate change in 

agriculture by improving planning, preventing maladaptation, 

and informing investment and resource management (Walthall 

et al. 2012). By tracking the successes and failures of different 

adaptation actions using agroforestry and other climate-smart 

agriculture strategies, effective, efficient, and equitable policies 

and measures can be identified that can lead to more robust 

adaptation strategies over time (Preston et al. 2011).

Key Findings

• The multifaceted nature of agroforestry practices and the 

diversity of landowner considerations require a suite of 

decision-support tools.

• A variety of decision-support tools addressing biophysical, 

economic, and social considerations are available for 

applying agroforestry.

• Financial and technical assistance from Federal and State 

conservation programs and private organizations has proven 

valuable in implementing agroforestry practices.

Key Information Needs

• Strengthen the analytical capacity of decision-support tools 

for agroforestry.

• Continue developing targeting tools that identify locations 

for implementing agroforestry practices that concurrently 

achieve landowner and societal goals. 

• Develop decision-support tools that enable comparisons of 

tradeoffs among climate-smart agriculture options at the 

scale of the decisionmaker.

• Involve end users in the development of the decision-support 

tools to ensure the tools match their needs and capabilities.
98 Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions

Box 6.1. COMET-FarmTM

COMET-Farm is a Web-based tool enabling farmers, 

ranchers, resource professionals, and others to assess the 

greenhouse gas (GHG) balance of land use and management. The tool allows for assessments of the GHG emissions 

and potential for carbon sequestration in farming, ranching, 

agroforestry, other livestock operations, and on-farm/ranch 

energy use. COMET-Farm estimates the GHG footprint for 

all or part of a user’s farm/ranch operation and enables the 

user to evaluate the GHG benefits of conservation practices. 

General guidance is provided about potential changes to 

management practices that are likely to sequester carbon 

and reduce GHG emissions.

Because the tool uses detailed spatially explicit data on 

climate and soil conditions for a user’s location and allows 

users to enter detailed information for field and livestock 

operations, it is able to produce an accurate estimate tailored 

to a user’s specific situations. No previous training is required 

to run the tool, and embedded Help functions are provided. 

The tool guides the user through describing farm and ranch 

management practices, including alternative future management scenarios. After this setup process is complete, the 

tool generates a report comparing the carbon changes and 

GHG emissions between current management practices and 

future, alternative scenarios.

Agroforestry assessments conducted in COMET-Farm use a 

stock-change method. This tool enables a user to describe 

agroforestry practices according to the number of trees in 

his or her system and the sizes (diameters) of those trees; 

from this information, the tool calculates the biomass carbon 

stock now and at 10-year intervals for 50 years in the future 

and a yearly average. Biomass carbon stocks and change 

rates are calculated based on growth equations developed 

from the Forest Inventory and Analysis database of the U.S. 

Department of Agriculture (USDA), Forest Service.

COMET-Planner is another tool available within the COMET-Farm suite of tools that can be used to provide a quick 

and broad estimate of GHG potentials of implementing 

USDA Natural Resources Conservation Service conservation 

practice standards, including agroforestry practices. This 

tool considers impacts on GHG including woody biomass 

carbon accumulation, change in soil organic matter carbon 

due to cessation of tillage and increased carbon inputs from 

plant residues, and decreased nitrous oxide from lower 

synthetic fertilizer application due to the implementation of 

an agroforestry practice. Users need only enter location data, 

select the practices, and select the acreage under these 

practices to generate a yearly estimate of the GHG emission 

reductions. Both tools are available for use at http://www.

comet-farm.com.

The COMET-Farm tool enables landowners to use spatially explicit data on climate and soils for their location and to input information 

on their field and livestock operations to produce an estimate of GHG emissions and potential for carbon sequestration. COMET-Farm is 

funded by grants from the USDA Natural Resources Conservation Service and the USDA Office of the Chief Economist.
Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions 99

Box 6.2. Economic Tools

Some of the most pressing questions for landowners wanting 

to know about incorporating agroforestry into their operations 

center on financial concerns, including costs, returns, risk, 

and uncertainty. Recognizing this need, the Center for Agroforestry at the University of Missouri (UMCA) developed several 

financial tools to help landowners explore those questions.

Agroforestry poses some unique economic budgeting 

challenges because it involves multiple enterprises with 

varying production cycles, such as trees, row crops, forages, 

and livestock. To help navigate these challenges, a step-bystep guide, Economic Budgeting for Agroforestry Practices

(Godsey 2010), provides a flexible process that can be 

applied to any agroforestry enterprise for estimating financial 

needs and feasibility, highlighting tradeoffs, and monitoring 

economic efficiency. This tool enables landowners to develop 

enterprise budgets and combine these budgets into annual 

cashflow plans for evaluation.

Several MicrosoftTM Excel-based economic tools are 

available from UMCA. The Windbreak Economic Model is a 

practice-based tool for estimating long-term financial benefits 

of windbreaks on crop yield. More detailed tools are available 

to evaluate the economic potential of black walnut (Juglans 

nigra) for nut and timber production and American elderberry 

(Sambucus canadensis) for fruit production. The Black Walnut 

Financial Model is a simplified model for assisting potential 

growers with making decisions about tree spacing, nut 

harvesting, and using improved (grafted) or unimproved trees.

The Elderberry Financial Decision Support Tool is designed 

to assist with elderberry establishment and management 

decisions. This model enables users to select options from a 

list of common establishment, management, harvesting, and 

marketing techniques to determine the mix of options that 

will generate the best economic returns. Each tool includes a 

random variable to simulate uncertainty in production due to 

annual weather conditions and other unpredictable events. 

Additional plant-specific tools are under development and 

soon will be released. The available tools and other financial 

resources are available at http://www.centerforagroforestry.

org/profit/#budget.

Elderberry is a hardy, multipurpose shrub that is suitable for many agroforestry practices. The fruit and flowers are edible and can be 

used for making wines, jams, syrups, and health tonics. The plant has other attributes, including attracting and benefiting birds, pollinators, and other wildlife; tolerating wet or poor soil conditions; and producing extensive root systems that can help reduce soil erosion. 

Photo: http://commons.wikimedia.org/wiki/File:Sambucus-berries.jpg.
100 Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions

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state and future needs. Agroforestry Systems. 61–62(1–3): 

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Foley, J.A.; DeFries, R.; Asner, G.P. [et al.]. 2005. Global 

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the process of developing a plot- and farm-scale model of 

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Howden, S.M.; Soussana, J.F.; Tubiello, F.N. [et al.]. 2007. 

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DC: National Fish and Wildlife Foundation. 12 p. http://www.

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Smith, C. 2012. The Washington State Conservation Reserve 

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Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions 101

Chapter 7

Expanding the North American Perspective—

Canada

Tricia Ward and Henry de Gooijer

Tricia Ward is an agroforestry specialist with Agriculture and Agri-Food Canada; Henry de Gooijer is a 

coordinating biologist with Agriculture and Agri-Food Canada.

Impacts of Climate Change on Canadian 

Agriculture

Canada has approximately 65 million hectares (ha) of productive agricultural land (Statistics Canada 2014), with agricultural 

activity generally limited to southern regions from the Atlantic 

Ocean to the Pacific Ocean (fig. 7.1). Assessments of climate 

change in Canada and its impact on Canadian agriculture 

conclude that most regions of Canada are projected to warm 

during the next 60 years (Warren and Lemmen 2014). For a 

high-altitude country like Canada, the warming is expected 

to be more pronounced than will be the global average. The 

results will likely be longer frost-free seasons and increased 

evaporation and plant transpiration. This warming may increase 

productivity, allow expansion of agriculture into new areas, and 

provide opportunities for the use of new and potentially more 

profitable crops (where soil conditions permit). These warmer 

temperatures could also benefit livestock production in the 

form of lower feed requirements, increased survival rates of the 

young, and lower energy costs.

Negative impacts from climate change also are expected, 

including increased intensity and frequency of droughts and 

violent storms. As the frequency of droughts increases, crop 

yields could decrease, particularly in semiarid regions of 

Canada. New pests and diseases will likely emerge, and more 

Figure 7.1. This map of Canada illustrates that most agricultural land is in the southern portion of the country. (Statistics Canada 

2012).
102 Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions

severe outbreaks of current ones will occur. Northern and 

remote communities are likely to see great changes in their 

environments—some will ease food security concerns, but 

others could exacerbate already decreasing food stocks and 

difficulties in delivering supplies into isolated areas.

Agroforestry Across Canada

In Canada, agroforestry provides ecosystem goods and services 

that support integrated management of farmland and rural 

spaces (De Baets et al. 2007). Ecosystem services derived from 

agroforestry practices typically include pollination services 

from wild pollinators; suppression of crop pests and diseases; 

nutrient cycling; carbon (C) sequestration; water purification, 

Box 7.1. Agroforestry in Canada and Its Link to the United States

Many ecological regions of North America span the Canada/

United States border, providing commonality in landscapes, 

climate, soils, wildlife, land management, and farming 

systems, including agroforestry. As such, Canada and the 

United States have a longstanding history of collaboration on 

agroforestry and formalized decades of collaboration through 

a Memorandum of Understanding (MOU) between Agriculture and Agri-Food Canada (AAFC) and the U.S. Department 

of Agriculture (USDA) in 2012. The MOU commits AAFC and 

the USDA to work together to accelerate the application of 

temperate agroforestry systems in agricultural landscapes, 

including research and science, outreach, education 

materials, and science tools for climate change mitigation 

that support the Global Research Alliance on Agricultural 

Greenhouse Gases.

USDA and AAFC jointly sponsored the Great Plains Windbreak Renovation and Innovation Conference in July 2012 

at the International Peace Garden (Manitoba-North Dakota 

border). The event brought together scientists, natural 

resource professionals, and landowners to discuss renovating windbreaks, some of which were first established to slow 

soil erosion during the Dust Bowl era. They also discussed 

ways to design multifunctional windbreaks. Approximately 

82 participants from 11 States and 3 Provinces attended the 

conference in person, and 35 joined remotely.

Presenters and participants at the Great Plains Windbreak Renovation and Innovation Conference in 2012. Photo courtesy of Agriculture 

and Agri-Food Canada.
Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions 103

cycling, and retention; and soil conservation and regulation 

of soil organic matter (Thiessen Martens et al. 2013). The 

ecosystem services of trees in tree-based intercropping (also 

known as alley cropping) have been the focus of several studies 

in Ontario and Quebec. Beneficial effects identified in these 

studies include increased soil organic C; greater C sequestration (Oelbermann and Voroney 2011, Peichl et al. 2006, 

Thevathasan and Gordon 2004); reduced leaching of water 

contaminants, including nitrate and Escherichia coli (Bergeron 

et al. 2011, Dougherty et al. 2009, Thevathasan and Gordon 

2004); reduced nitrous oxide (N2O) emissions (Beaudette et 

al. 2010); enhancement, diversification, and stabilization of 

arbuscular mycorrhizal fungi populations (Bainard et al. 2012, 

Chifflot et al. 2009, Lacombe et al. 2009); and augmentation 

of earthworm, bird, and insect populations (Thevathasan and 

Gordon 2004).

Many Canadian citizens are concerned about potential negative 

ecological impacts of agricultural production, and thus the role 

of agroforestry in Canada’s agricultural landscapes has largely 

been linked to lessening environmental impacts of modern 

agriculture while balancing productivity and environmental 

stewardship. Adaptation and mitigation to climate change 

impacts are emerging concerns, and key environmental benefits 

sought to address these concerns include C sequestration and 

greenhouse gas (GHG) reductions, soil conservation, nutrient 

management, and water-quality protection (Van Rees 2008). 

Capitalizing on multiple services is a primary objective. For 

instance, riparian buffer zones with poplar trees can be used for 

water-quality protection while producing biomass that could 

then serve as a biofeedstock source, ultimately reducing GHG 

emissions (Fortier et al. 2010a).

Because the climate, soil, landforms, and resource management 

systems vary among Canada’s five broad agricultural regions—

Atlantic, Quebec, Ontario, Prairies, and British Columbia—

agroforestry solutions will need to be region specific. For 

instance, a common agroforestry practice such as shelterbelts 

(table 7.1; Statistics Canada 2006) has been implemented 

across Canada, but the design characteristics, such as single 

rows versus multiple rows of trees and tree species selection, 

may vary from farm to farm and region to region based on 

agroecological conditions. The remaining paragraphs in this 

section summarize agroforestry trends and opportunities in 

each region.

Atlantic

In Canada’s Atlantic region, comprising the Provinces of New 

Brunswick, Newfoundland and Labrador, Nova Scotia, and 

Prince Edward Island, a large percentage of the land area is 

forested and government owned. Many agricultural producers 

have woodlots that generate significant income through the 

sale of wood as a source of fuel and pulp fiber. The purposeful 

integration of trees and shrubs into the agricultural landscape 

through the adoption of agroforestry practices has been less 

prevalent than farm woodlots. The interest in agroforestry, 

however, has grown in the region during the past 10 years.

Planting riparian forest buffers is one of the main agroforestry 

practices being used in this region, especially to address issues 

of soil erosion and contamination of watercourses by sediments, 

nutrients, and pesticides from intensive potato production. Each 

Atlantic Province has some form of environmental legislation 

that can affect the choice of agroforestry system that the Province 

adopts, particularly the use of riparian forest buffers (ADI Limited 

2007). Multirow riparian forest buffers with willow (Salix spp.) 

as the primary species are being looked at for their potential 

to effectively buffer adjacent waterways and also to provide 

harvestable biomass and C sequestration (fig. 7.2). Although 

forest farming has only recently been introduced in the region, 

the potential for diversifying products and income under climate 

change is significant, given the number of agricultural producers 

that have woodlots.

Figure 7.2. Willow riparian forest buffer on Prince Edward 

Island. (Photo courtesy of Agriculture and Agri-Food Canada).

Table 7.1. Shelterbelt adoption in Canada’s agricultural regions. 

Agricultural region Total farms reporting Number of farms reporting shelterbelts Percentage of farms reporting shelterbelts

Atlantic 8,829 2,525 29

Quebec 30,675 5,994 20

Ontario 57,211 19,044 33

Prairies 112,814 52,365 46

British Columbia 19,844 4,794 24

Canada 229,373 84,722 37

Source: Statistics Canada (2006).
104 Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions

Quebec

Notwithstanding maple syrup production by woodlot landowners, 

which is a well-established industry in the Quebec and Atlantic 

regions, agroforestry has not been traditionally practiced in 

Quebec. Because of growing social pressure for sustainable 

management of the Province’s natural resources, combined with 

the economic and environmental challenges that the agricultural 

and forestry sectors face, however, agroforestry is attracting 

greater attention and popularity (De Baets et al. 2007).

Planting shelterbelts is the most widespread agroforestry 

practice in Quebec, with approximately 400 kilometers being 

planted annually since the mid-1980s to protect crops, soil, 

livestock, buildings, and roads from the wind (De Baets et al. 

2007). In the early 2000s, windbreaks began to be planted to 

reduce odors from intensive livestock operations. Though not 

as widely adopted as windbreaks, riparian forest buffers have 

been receiving increased attention from environmental and 

agricultural stakeholders (Fortier et al. 2010b).

Maintenance of a network of trees distributed throughout 

modified landscapes, such as those of southern Quebec, where 

cultivated fields form a significant component, is an option for 

facilitating climate change adaptation (Auzel et al. 2012).

Since 2004, provincial and Federal funding agencies have 

supported research on tree-based intercropping (fig. 7.3) in 

Quebec (Hesselink and Thevathasan 2012). Current research 

in Quebec and Ontario is attempting to quantify the capacity 

of this practice to mitigate the impact of agricultural GHGs. 

Several years of field trials indicate that widespread adoption 

of tree-based intercropping could improve current agricultural 

systems and also provide various social, economic, and ecosystem services to rural communities and to society as a whole. If 

applied on a large scale, tree-based intercropping systems could 

substantially reduce agricultural GHG emissions and increase 

atmospheric C sequestration in soils and woody biomass.

Figure 7.3. Young alley cropping system in southern Quebec. 

(Photo courtesy of David Rivest).

Ontario

Tree-based intercropping systems have been widely researched 

in relation to their ecosystem services (fig. 7.4). 

Figure 7.4. Tree-based intercropping research site at Guelph, 

Ontario. (Photo courtesy of Naresh Thevathasan, the University 

of Guelph).

The major areas of research include C sequestration, N2O 

reduction potentials, nutrient leaching reduction and improved 

water quality, enhancement of bird diversity and earthworm 

activity, and woody biomass production for bioenergy. It is 

possible for these systems to make a considerable contribution 

to climate change mitigation. Thevathasan and Gordon’s (2004) 

research determined that, because of reduced fertilizer use 

and more efficient nitrogen-cycling, tree-based intercropping 

systems could contribute to the reduction of N2O emissions 

from agricultural fields by about 0.7 kilograms per hectare (ha) 

per year (1.5 pounds per acre per year).

The ecobiological processes and the combined tree and crop 

yields provide tangible benefits that show tree-based intercropping 

has increased capacity over conventional agricultural systems 

in terms of long-term overall productivity (Thevathasan et al. 

2004). Dyack et al. (1999) determined that the low adoption 

rate of tree-based intercropping systems is partially due to current 

tax policies that do not take into consideration the numerous 

intangible, societal-level benefits associated with agroforestry 

systems. Adoption of these systems is also hindered by initial 

establishment costs and also by the income loss resulting 

from the removal of cropland from production. An economic 

analysis (Toor et al. 2012) found that tree-based intercropping 

systems in central Canada were less profitable than annual 

cropping systems due to reduced area for annual crops and low 

revenue from trees, especially when trees were slow-growing 

timber species such as red oak (Quercus rubra L.).

The Prairies

Canada’s Prairies region comprises the Provinces of Alberta, 

Manitoba, and Saskatchewan. Widespread agricultural 
Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions 105

settlement occurred rapidly after the railroads were built in the 

early 1880s. Agroforestry activities in this region began soon 

afterward. Many settlers acutely felt the need for shelter on the 

wide-open, windy, treeless southern plains, but the need was 

less in the more wooded northern and eastern portions of the 

Prairies region.

In 1886, the Federal Government adopted the Experimental 

Farm Stations Act; it was through this program that tree nurseries were developed to produce tree and shrub seedlings (Van 

Rees 2008). Early agricultural settlers, while adamant about 

clearing land for agricultural practices, were also cognizant of 

the important roles that trees play in sustaining farm systems, 

and they appreciated the products and services that could be 

derived from trees. Multirow farm shelterbelts surrounding 

yards and single-row field shelterbelts became the predominant 

tree culture practiced on the prairie landscape (Edwards 1939).

Federal programming supported the planting of shelterbelts 

on the prairies since 1901 (fig. 7.5), including the provision 

of seedlings through the Federal tree nursery at Indian Head, 

Saskatchewan, and, from 1935 to 1959, special support for establishing field shelterbelts for erosion control under the Prairie 

Farm Rehabilitation Act (Amichev et al. 2014). Throughout 

the period from 1901 to 2013, more than 630 million seedlings 

were provided for protecting farmyards and fields and were 

used for other environmental plantings through the Prairie 

Shelterbelt Program, enough seedlings to potentially sequester 

more than 218 megatonnes of carbon dioxide (CO2

) during the 

lifetime of the trees (Kort and Turnock 1999).

As a result of the Saskatchewan’s State of the Environment

Report 1997 (Saskatchewan Environment and Resource Management 1997), which highlighted the need to support research and 

development in emerging value-added sectors in agriculture, 

the Province of Saskatchewan created the Agri-Food Innovation 

Figure 7.5. Farmyard and field shelterbelts near Francis, Saskatchewan, established with seedlings provided through the 

Prairie Shelterbelt Program. (Photo courtesy of Agriculture and 

Agri-Food Canada).

Fund (AFIF). Developing sustainable agroforestry economic diversification opportunities for farmers was one of the five priority 

areas of AFIF, with much of the emphasis on poplar-afforestation 

and small woodlots, with research and demonstration directed 

toward efforts that could supplement traditional forest products 

and harvest (Van Rees 2008).

Land tenure in the Prairies region continues to evolve toward 

larger specialized farms with more corporate ownership of farming 

operations on rented land. The predominance of large-scale 

agriculture and the introduction of precision farming technology 

have led to a noticeable reduction in habitat on marginal lands 

adjacent to agricultural fields. Although improved land management techniques, such as zero tillage, can help mitigate the negative 

impact of the loss of shelterbelts, the positive functionality of 

agroforestry systems cannot be adequately replaced by monoculture farming practices (Schroeder et al. 2011). The domestic 

market provides opportunities for more specialized, often smaller, 

farm enterprises, such as organic farms and market gardens. 

Corporate farms may be less interested in tree planting or other 

environmental practices that are not seen as profit-generating 

activities, and farming on rented land may also present 

obstacles to long-term conservation practices with trees. Public 

concern about environmental issues, however, may encourage 

corporate farms to make sound environmental management of 

the landscape an essential part of their core business.

British Columbia

Agroforestry applications within British Columbia have 

evolved from efforts to integrate resource practices on public 

lands to, more recently, a means of economic diversification 

and as an approach to environmental stewardship.

Shelterbelts were reported on less than 25 percent of the farms 

in the Province (Statistics Canada 2006). The low percentage 

of adoption may be reflective of generally naturally treed 

landscapes of many agricultural areas of British Columbia and 

a need for more shelterbelt design, demonstration, assessment, 

and management for a variety of agricultural production systems. 

In British Columbia, producers rank economic efficiency and 

effectiveness as the most important criteria for decisionmaking, 

followed by adoptability, adaptability, flexibility, and independent benefits (Dobb 2013).

Various natural and land management elements—including 

success in using sheep grazing for silvicultural purposes since 

1984, economic diversification efforts in coastal woodlots starting 

in the mid-1990s, and the mountain pine beetle (Dendroctonus 

ponderosae Hopkins) epidemic in the British Columbia 

interior—converged, creating awareness of agroforestry’s potential 

usefulness in British Columbia. This awareness has given 

rise to organized research, pilot projects, and demonstration 

initiatives, as illustrated in figure 7.6.
106 Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions

Figure 7.6. Silvopasture pilot site, southern interior of British 

Columbia. (Photo courtesy of British Columbia Ministry of 

Agriculture).

Significant opportunity exists in the implementation of silvopastoral systems and riparian forest buffers to address concerns 

related to water quality and also to provide additional economic 

opportunities other than those based on forestry products. 

Development of agroforestry in British Columbia is driven by 

partnerships among producers and industry associations; First 

Nations; academic institutions; nongovernmental organizations; 

and municipal, provincial, and Federal Government agencies 

(Dobb 2013).

Overview of Existing Policies and Programs

“Climate change is perhaps the greatest environmental policy 

challenge of the 21st century” (Gleeson et al. 2009). Effective 

policies supporting agroforestry land-use systems in Canada 

can provide the framework for landowners and land managers 

who may become active agents of change through their own 

personal undertakings and examples. At present, few specific 

policies exist at any level of government that govern agroforestry practice and adoption. Policies and programs that do exist 

are not coordinated across provincial jurisdiction and generally 

are limited in the time they are available. More likely, agroforestry practices will be influenced by other agricultural policies 

affecting land use or, in some instances, forest management 

regulation changes.

To obtain successful adoption rates and well-maintained 

agroforestry systems across Canada, policy measures and/or tax 

incentives and cost-share programs will likely be required at 

Federal and/or provincial levels of government.

Federal

To date, the only Federal organization that has a national 

agroforestry mandate is Agriculture and Agri-Food Canada 

(AAFC). Activities in support of agroforestry and tree planting 

in the agricultural landscape have existed at the Federal level 

of government since 1901. Activities in research, development, 

and tree distribution have continually evolved during the past 

century based on environmental and economic drivers and to 

meet the needs of the changing agricultural sector. Additional 

regional and national strategies for agroforestry, with the goal 

of improving the competitive position of the agricultural sector 

by incorporating agroforestry systems for the sustainable 

management of the agricultural land base, have also evolved 

over time (Van Rees 2008).

Federal-provincial cost-share agreements integrate environmental actions across levels of government and focus programs 

on helping producers reduce environmental risks and improving benefits. The current agricultural framework agreement, 

Growing Forward 2, continues to encourage agricultural producers to adopt management practices that benefit the environment 

and sustain the natural systems that provide ecosystem goods 

and services. For example, in Saskatchewan, eligible landowners can receive funding through the Farm Stewardship Program 

at a rate of $1,200 Canadian dollars (CAD) ($904 U.S. dollars 

[USD]) per mile to a maximum payment of $5,000 CAD 

($3,769 USD) (Government of Saskatchewan, 2016). Table 7.2 

lists the number and funding of projects involving agroforestry 

practices under the Agricultural Policy Framework.

Table 7.2. Agroforestry-related projects by Province funded 

under the Agricultural Policy Framework.

Province Number 

of projects

Funding

(Canadian dollars, thousands)

Alberta 98 250

British Columbia 29 207

Manitoba 73 139

New Brunswick 10 21

Newfoundland 0 0

Nova Scotia 5 6

Ontario 336 586

Prince Edward Island 3 7

Quebec 1,081 1,086

Saskatchewan 64 100

Totals 1,729 2,399

Source: Agriculture and Agri-Food Canada program data.

As illustrated, support and promotion at the provincial level can 

have a significant effect on the uptake of program initiatives 

by producers in a region. Projects in Alberta, Manitoba, and 

Saskatchewan, although lower than those in Ontario and 

Quebec, do not take into account most of the tree-planting 

activities that would have occurred under the Prairie Shelterbelt 

Program, which provided trees, on average, to 5,000 or more 

landowners annually.
Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions 107

Agricultural Greenhouse Gases Program

The Canadian Government, through AAFC, has initiated and 

promoted a national network of agroforestry practitioners in 

research and development through the Agricultural Greenhouse 

Gases Program (AGGP). This proposal-based program is part 

of GHG mitigation initiatives undertaken in countries that 

are members of the Global Research Alliance and ran from 

September 1, 2010, to March 31, 2016. The AGGP supports 

projects that will create technologies, practices, and processes 

that can be adopted by farmers to mitigate greenhouse gas 

(GHG) emissions.

Within the priority area of agroforestry, six projects within 

the Agricultural Greenhouse Gases Program (table 7.3) were 

funded at a level of $4.85 million CAD. These projects address 

knowledge gaps and increase capacity in two main theme areas: 

(1) understanding C sequestration on agricultural land through 

agroforestry systems and (2) adoption and efficacy of agroforestry practices. Areas of study in the first theme encompass 

the understanding of C dynamics in agroforestry practices, 

including aboveground and belowground C pools and fluxes; 

quantifying the potential for agroforestry practices to store C on 

agricultural land; and developing methodology for the measurement, monitoring, and verification of C in agroforestry systems, 

all providing a basis for a national inventory of C in agroforestry systems in Canada. Areas of study under the second theme 

include assessments of how agroforestry practices interact with 

or affect agricultural practices, the quantification of co-benefits, 

and C sequestration from agroforestry systems. The six projects 

are also examining existing policies and developing policy 

tools that encourage sustainable and effective GHG mitigation 

practices, and conducting life-cycle assessments and economic 

analyses to assess the sustainability and performance of 

agroforestry systems for GHG mitigation.

Provincial

In Quebec, in 2011, the provincial Department of Agriculture, 

Fisheries and Food of Quebec (MAPAQ; Ministère de 

l’Agriculture, des Pêcheries et de l’Alimentation du Québec) 

launched a pilot program on the multifunctionality of 

agriculture, specifically targeting agroforestry and tree-based 

intercropping systems as production systems for which the 

implementation of such systems may qualify for a subsidy. 

This pilot program ended in March 2015. Some other Quebec 

departments have also considered the various functions of 

agroforestry. For many years the Quebec Ministry of Natural 

Resources (Ministère des Ressources Naturelles du Québec) 

has provided trees for windbreaks and riparian forest buffers in 

collaboration with MAPAQ. Various timber-oriented agroforestry projects have also been funded through a regional forest 

development program, now titled the Regional and Forestry 

Development Program (Programme de développement régional 

et forestier) (Government of Quebec 2013). The Quebec Ministry of Transportation (Ministère des Transports du Québec) 

implements windbreaks in rural areas to reduce snow-control 

costs. In a perspective of regional development, the Quebec 

government’s Ministry of Municipal Affairs, Regions and Land 

Occupancy (Ministère des Affaires municipales et de l’Occupation du territoire) also supported experimental agroforestry 

development projects, notably tree-based intercropping systems 

Table 7.3. The six agroforestry projects funded under the Agricultural Greenhouse Gases Program. 

Lead institution Title Primary objective

Government of British 

Columbia

Evaluating silvopasture systems for economic 

and environmental performance and greenhouse gas mitigation potential

Examine how the practice of combining forestry with forage 

and livestock production in the southern interior of British 

Columbia will support greater biological and economic diversity 

and benefit the environment.

University of Alberta Quantifying carbon sequestration and greenhouse gas emissions in planted shelterbelts, 

natural hedgerows and silvopastoral systems in 

different soil-climatic zones in Alberta

Quantify the value of shelterbelts, natural hedgerows, and 

silvopastoral systems for facilitating carbon storage and 

reducing greenhouse gas emissions.

University of Saskatchewan Shelterbelts as an agroforestry management 

practice for the mitigation of GHGs

Determine how effective shelterbelts and other agroforestry 

plantings are in sequestering carbon and how they can better 

function as carbon sinks.

Upper Assiniboine River 

Conservation District

Demonstration and investigation into agroforestry 

based livestock systems adoption

Evaluate various beneficial management practices on the farm 

to see if they can be easily adopted by the farming community.

University of Guelph Tree-based intercropping: An agroforestry landuse for greenhouse gas mitigation in Canadian 

agricultural systems

Assess how tree-based intercropping can mitigate greenhouse 

gas emissions and enhance carbon sequestration in tree biomass and agricultural soils.

Eastern Townships Forest 

Trust

Effects of hybrid poplar agroforestry systems on 

carbon sequestration in agricultural landscapes 

of Eastern Canada

Determine the potential for riparian and upland agroforestry 

buffers to sequester carbon in agricultural landscapes in 

Eastern Quebec.

Source: Agriculture and Agri-Food Canada program data.
108 Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions

in the Gaspe Peninsula. Moreover, some municipalities are 

exploring agroforestry approaches as a means to increase the 

value of abandoned land, to enhance green corridor acceptance 

among farmers, and to offset C emissions from urban areas.

In British Columbia, the Agroforestry Industry Development 

Initiative (AIDI) supported the development and adoption 

of agroforestry practices by improving market connections, 

expanding partnerships, improving awareness, and establishing 

demonstrations. Funding for AIDI was provided by AAFC 

through the Canadian Agricultural Adaptation Program from 

2010 to 2013 and was delivered by the Investment Agriculture 

Foundation of British Columbia.

Alternative Land-Use Services

Financial incentives have become popular for protecting the 

environment in Canada (Lantz et al. 2012). Alternative LandUse Services (ALUS) are community-developed, farmer-delivered 

programs that provide incentives to farmers and ranchers for 

the conservation and protection of environmental assets on 

privately owned land (ALUS 2016, Keystone Agricultural 

Producers 2011). Most of the current programs rely on grants 

through nongovernment funding agencies (Campbell 2014).

The goals of ALUS programs are to empower landowners in 

conservation, to increase the supply of environmental goods 

and services, and to improve land management by reducing soil 

erosion, improving water quality, improving and increasing 

wildlife habitat, and reducing the impacts of climate change 

(Government of PEI 2012). The current impact of ALUS 

programs has been minimal regarding agroforestry; approximately 243 ha (600 acres [ac]) have been planted in trees and 

shrubs across Canada, with most planted in Ontario. Many of 

these seedlings are provided by the Ontario Ministry of Natural 

Resources and Forestry’s 50 Million Tree Program. With goals 

of sequestering C and of enhancing and diversifying southern 

Ontario’s landscape to increase adaptive capacity and resiliency 

regarding climate change, the program substantially decreases 

costs of large-scale tree planting to increase the total number of 

trees planted (Forests Ontario 2016) In the Province of Prince 

Edward Island, 251 ha (620 ac) of tree planting within the 

15-meter (49-foot) regulated buffer zone have been established 

and expanded buffer zones (beyond 15 meters [49 feet]) have 

been created on 553 ha (1,366 ac) (ALUS 2012) with payments 

of $185 CAD ($139 USD)/ha/year (Lantz et al. 2012).

Ecosystem Goods and Services

The value that ecosystem goods and services produced from 

establishing agroforestry practices is significantly higher for the 

public than the costs they engender for farmers (EcoRessources 

Consultants 2011). Some of the most important benefits relate 

to C sequestration. Kulshreshtha and Kort (2009) estimated 

that the benefits of tree seedlings distributed through the Prairie 

Shelterbelt Program for the period from 1981 to 2001 was $73 

million CAD ($47 million USD) for C sequestration. Some 

indications suggest that the demand for ecosystem goods and 

services from rural lands is growing as incomes rise and values 

change in Canadian society, but the supply side does not seem 

to be responding (Fox 2008).

Current discussions of alternative approaches to facilitating the 

provision of ecosystem goods and services have not made a 

distinction between taxpayer-funded programs and beneficiary-funded market programs (Fox 2008). To develop programs 

and policies that recognize and support the contributions that 

landowners make through agroforestry, a greater understanding 

of the benefits of ecosystem goods and services will be needed 

(Kulshreshtha and Kort 2009).

Needs for Agroforestry in Canada

Although each Canadian Province has its own unique preference 

to different agroforestry systems adapted for local conditions, 

the challenges/constraints and potential impacts are similar 

across the Provinces (Thevathasan et al. 2012). Key research 

needs across the Provinces include understanding of the evolution 

of agroforestry practices in light of changing socioeconomic 

and environmental conditions; evaluation of the ecosystem 

goods and services provided by different types of agroforestry 

systems; accounting for potential impacts (both benefits and 

concerns) of agroforestry systems at the landscape level; 

and understanding how agroforestry can best be included in 

management of water quality and GHG mitigation in agricultural watersheds, and in emerging taxation and credit schemes. 

To address these needs, continued studies and analyses of the 

economics, risks, and life-cycle components of agroforestry 

systems currently found on the Canadian landscape will be 

required. The formation of a national agroforestry network 

would provide a means for efficiently addressing these many 

issues and building the scientific information needed at both the 

regional and national levels (Van Rees 2008).

Adaptability of Species Used in Agroforestry

Having woody plant material that is adapted to the future 

climate conditions in Canada will be critical to the success of 

agroforestry as a climate change tool (Johnston et al. 2009, 

Silim 2004). Tree species currently used and potentially available for use in Canada are vulnerable to erratic and extreme 

weather events and also to climate-induced fluctuations in 

insects and pathogens (Allen et al. 2010, Fuhrer 2003). It is 
Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions 109

essential to understand the vulnerability of tree species under 

predicted climate change to determine reasonable options for 

adaptation of agroforestry plant materials.

The Agriculture Canada Balsam Poplar (AgCanBaP) program 

is focused on developing adaptable balsam poplar (Populus 

balsamifera L.) materials. Occurring across a wide range of 

North America, balsam poplar is both highly variable and 

capable of a broad range of adaptive physiological responses to 

a changing climate (Keller et al. 2011). With its natural range 

in Canada extending from coast to coast, balsam poplar is one 

of the most widely distributed poplars in Canada. Researchers 

at AAFC who have advanced genetic improvement on a 

number of species have also now assembled a balsam poplar 

collection. The AgCanBaP collection consists of material from 

throughout North America that provides germplasm for future 

climate change, breeding, and genomic studies (fig. 7.7). This 

collection is currently being screened to identify fast-growing 

selections that have greater C sequestration and biomass yields 

(Soolanayakanahally 2010).

GHG Accounting and Inventory

Significant potential exists for agroforestry to contribute to 

Canada’s GHG mitigation goals. Canada has an estimated 57 

million ha (141 million ac) of agricultural land that have slight 

to significant degrees of agricultural crop production limitations. If 5 percent of this land area were converted to agroforestry, the potential for an annual C sink of 47 to 76 megatonnes 

of CO2 (up to 30 percent of the emission reductions for Canada) 

would exist (Van Rees 2008).

Information on GHG accounting from agroforestry practices is 

not fully developed, however, and, therefore, is not currently 

reported in the National Inventory Report (NIR) on GHG 

sources and sinks in Canada. As the Canadian government’s 

submission to the United Nations Framework Convention 

on Climate Change, NIR provides an annual report on GHG 

accounting across sectors, including agriculture and land use, 

land-use change, and forestry. Impacts of changes in woody 

biomass in the agricultural landscape is characterized under 

“perennial woody crops” in the NIR and includes land-use 

Figure 7.7. Natural range of balsam poplar (Populus balsamifera L.) and geographic locations of 65 provenances (indicated by 

green dots) and common garden locations (indicated by red stars) in the AgCanBaP program (Soolanayakanahally et al. 2013). 

(Map created by Chris Stefner, Agriculture and Agri-Food Canada).
110 Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions

activities such as vineyards, fruit orchards, and Christmas trees 

reported under the Canadian Agricultural Census on a 5-year 

basis. Current estimates of sequestration from perennial woody 

crops account for the removal of only 10 gigagrams of carbon 

dioxide equivalent (CO2eq) (Environment Canada 2014). 

Compared with sequestration from practices such as reduced 

fallow or tillage, woody biomass seems to have an insignificant 

effect on total C removals. This seeming insignificance is an 

accounting byproduct resulting from the lack of inventory of 

agroforestry practices in Canada and the lack of activity-specific data on the GHG impacts of agroforestry practices. The 

Agricultural Greenhouse Gases Program is addressing both 

deficiencies.

Emerging Opportunities

In an increasingly complex commodities mix, it is beneficial 

that various economic diversification strategies be available to 

Canadian landowners through agroforestry systems (Gordon et 

al. 2008). Bioenergy from short-rotation willow and/or poplar 

has considerable potential for the future because economic 

inputs in some woody bioenergy systems are substantially less 

than those involved in grain-based systems used for ethanol 

production. Agroforestry, as stated by Gordon et al. (2008), 

offers long-term rural landscape sustainability and provides 

economic resilience through income diversification.

It has been suggested that payments in a C market or a grant/

subsidy program for ecological services are necessary to 

encourage adoption of agroforestry practices (EcoRessources Consultants 2011, Thiessen Martens et al. 2013). It is 

anticipated that as C markets emerge, agroforestry plantings 

will generate C offsets and provide revenue for landowners. 

The Government of Alberta has created the Climate Change 

and Emissions Management Fund to establish or participate 

in funding for initiatives that reduce emissions of GHGs or 

improve Alberta’s ability to adapt to climate change and has 

placed a value of $15 CAD ($11 USD)/tonne CO2

eq (IETA 

2015). British Columbia has also developed a C market with 

offset prices being paid in the range of $9 to $19 CAD ($7 to 

$14 USD)/tonne CO2eq (IETA 2015).

Key Findings

• As Canadian agriculture likely expands into new areas under 

changing weather and climate conditions, agroforestry can 

be an important component in enhancing food security, 

particularly in northern and First Nation communities.

• Agroforestry can play a critical adaptation role in existing 

agricultural areas as these lands experience more extreme 

and variable weather events, increased pest infestations, and 

other climate-related stressors.

• Agroforestry systems can have a significant effect in 

mitigating GHG emissions from Canadian agricultural 

activity if agroforestry implementation is increased.

• Climate, soils, and agricultural systems vary considerably 

across the broad farming and ranching areas in Canada, 

requiring agroforestry solutions to be region specific.

Key Information Needs

• Better understanding of GHG dynamics across Canadian 

agroforestry systems and regions.

• A national inventory to track land currently in agroforestry 

to feed into Canadian GHG inventory assessments.

• Development of a Canadian agroforestry network to help 

build the scientific information and support needed at both 

regional and national levels.

• Coordinated land-use policy between levels of government 

that addresses both short-term economic pressures of the 

landowner (private risk) and longer term public benefit.

Box 7.2. Enhancing Food Security in Northern Canada With Agroforestry

Food insecurity is one challenge that First Nations people 

residing in northern Canada face. Warming temperatures are 

already creating many other challenges for these communities, 

especially for those in the more remote subarctic and arctic 

regions of northern Canada. These warming temperatures, 

however, also provide an opportunity to build food security 

through local agricultural production. Work by Barbeau et al. 

(2015) demonstrates that with the selection of appropriate 

plant materials, potatoes and bush beans could be grown 

successfully and used as a source of local, fresh, and nutritious foods. They also found that yields could be significantly 

enhanced by growing the crops in alleys between rows 

of willows. By capitalizing on this windbreak function and 

with the resiliency and potential other uses of and services 

from willow (i.e., biodiversity including pollinator habitat, C 

sequestration, soil conservation, and biofeedstock), agroforestry can be more specifically designed to better meet the 

needs of the people in these regions.
Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions 111

Literature Cited

ADI Limited. 2007. Assessment of the market potential of 

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Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions 113

Chapter 8

Expanding the North American Perspective—

Mexico

Heidi Asbjornsen

Heidi Asbjornsen is an associate professor, University of New Hampshire, Department of Natural Resources 

and the Environment.

Contributors: Robert Manson, Citlalli López Binnqüist, and Patricia Negreros-Castillo

Robert Manson is a professor and Coordinator of the Functional Ecology Network, Institute of Ecology, 

Mexico National Board of Science and Technology; Citlalli López Binnqüist is a researcher, University of 

Veracruz, Center for Tropical Research; Patricia Negreros-Castillo is a researcher, University of Veracruz, 

Center for Tropical Research.

Impacts of Climatic Variability on Mexican 

Agriculture

Based on national assessments, Mexico is expected to see 

temperature increases of 0.9 to 2.5 oC by the year 2020, and 

it is very probable that, by the year 2050, the climate will be 

warmer by 2.0 to 4.0 oC, especially in the central and northern 

parts of the country (MENR 2007). Rainfall is expected to 

decrease as much as 15 percent in the central part of the country, 

but the number of severe storms and the intensity of severe 

droughts are expected to increase nationwide (MENR 2007).

Mexican agriculture will be particularly vulnerable to these 

predicted changes in climate. Changes in precipitation may 

have the greatest impact, because most of the country’s agricultural land (about 85 percent) is classified as arid or semiarid 

(Houghton et al. 2001). Increases in temperatures and soil moisture 

deficits will likely decrease land area suitable for rain-fed crops 

such as maize. Severe droughts will compound the situation in 

a country where, on average, more than 90 percent of agricultural losses are already attributed to drought events (Appendini 

and Liverman 1994). More intense tropical storms in the 

southern and coastal parts of the country are likely to cause 

extensive damage to crop and livestock production. It is also 

anticipated that changing weather and climate will increase the 

scale and frequency of forest fires, which may contribute to a 

shift from tropical forests to savannas (MENR 2007). Reducing 

agricultural vulnerability to climatic variability is of critical 

importance in the agricultural sector in Mexico, especially 

given the role the sector plays in support of food security and 

livelihoods of rural populations.

Agroforestry systems are gaining greater attention within 

Mexico as one strategy for mitigating and adapting to predicted 

climate change. Work by Locatelli et al. (2011) identified agroforestry as a tool for adaptation, enabling poor rural families, 

communities, and watersheds to be less vulnerable to extreme 

and erratic weather events by generating diverse environmental 

and socioeconomic benefits. This contribution by agroforestry 

systems was also recognized in Mexico’s National Climate 

Change Strategy, which serves as a guide for Mexico’s actions 

during the next 40 years (SEMARNAT 2013). This Federal 

strategy targets the reduction of greenhouse gas emissions, and 

specifically includes initiatives related to agroforestry.

In this chapter, we first provide an overview of the history of 

agroforestry in Mexico, focusing on the most prominent agroforestry systems and their associated tree and crop species, 

management practices, geographic range, and environmental 

and climatic conditions. When available, we also provide information about the agroforestry systems’ potential for enhancing 

climate change mitigation (through carbon sequestration and 

storage) and adaptation to climate change (through improving 

food security and resilience). Next, we discuss the existing 

Government policies aimed at promoting different agroforestry 

practices and how these relate to important long-term goals 

related to climate change mitigation or adaptation. Finally, we 

describe some major constraints to the adoption of agroforestry 

systems and also the needs and emerging opportunities for 

agroforestry in Mexico.
114 Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions

Overview of Agroforestry in Mexico

Mexico has an area of 1.97 million square kilometers (761,200 

square miles) and is one of the 14 most biodiverse countries 

in the world (Mittermeier et al. 1998). Together with its large, 

diverse mosaic of climatic zones, terrestrial ecosystems, and 

plant and animal species, Mexico has immense cultural diversity 

that has contributed a wide range of different domesticated crops 

(e.g., corn, bean, cocoa, vanilla, pineapple, avocado, amaranth, 

chia) and also land-use systems that include agroforestry (Toledo 

et al. 2001, 2003). Agroforestry practices were known to have 

been implemented during pre-Hispanic times, based on evidence of production systems that combined crops and multipurpose trees (Barrera et al. 1977). According to Moreno-Calles 

et al. (2014), the most well-documented examples include the 

chinampas (e.g., floating gardens with trees and crops) that 

the Aztecs used in central Mexico and the homegardens (e.g., 

complex combinations of crops, livestock, and multipurpose 

trees established adjacent to the home) that the Mayans used 

in the Yucatan. Agroforestry systems are especially typical of 

the extensive tropical habitats, where they are characterized 

by complex, spatially and temporally stratified combinations 

of trees, crops, and animals. Combined with other production 

strategies, such as roza-tumba-quema (slash-and-burn), these 

systems were implemented extensively in pre-Hispanic times.

During the long history of agroforestry in Mexico, the most 

important objective has been the production of subsistence food 

crops and other immediate necessities, such as fiber, medicine, 

and fuel wood, and only more recently have other products of 

commercial value been included to a great extent (Moreno-Calles 

et al. 2014). Although most agroforestry systems have not contributed significantly to country-level agricultural production 

and commercialization based on volume or land cover, they 

have been vital to sustaining rural farmers and to retaining the 

cultural and biological diversity of Mexico.

Some of these agroforestry systems have been modified or 

expanded more recently in response to the introduction of 

foreign crops like coffee, the internationalization of markets, 

technological advances, and changing policy and economic 

environments, especially for valuable products such as coffee, 

cocoa, and vanilla.

Despite their long historical importance, agroforestry systems 

in Mexico first gained broad recognition and relevance in 1991, 

when a collaborative agreement was signed by the International 

Center for Research in Agroforestry and the Institute of Forest, 

Agriculture, and Animal Husbandry Research in Mexico. This 

collaboration lasted about 10 years and resulted in several 

long-term research programs and the creation of educational 

and graduate programs focusing on agroforestry at major 

universities in Mexico.

The seven most common agroforestry systems in Mexico in 

recent times are (1) homegardens, (2) improved fallows, (3) 

living fences, (4) shade trees for agricultural plantations (e.g., 

coffee, cacao, fruit trees), (5) alley cropping (both with crops 

and fodder/pasture), (6) windbreaks, and (7) silvopastoral 

systems (Bautista 2009, Budowski 1987, CONAFOR 2014, 

Dominguez Alvarez and Sanchez Velez 1989, Garcia 2010, 

Gutierrez Ramirez 2006, Musalem-Santiago 2002, Santoyo 

2004, Wilken 1976).

It is notable that agroforestry systems in Mexico have been 

intimately linked with indigenous natural resource management 

practices, including the rapid adoption and integration of new 

crops (e.g., coffee) into existing indigenous agroforestry practices having high levels of biodiversity (Beaucage 1997). Based 

on biocultural diversity, Moreno Calles et al. (2013) identified 

three main types of agroforestry systems in Mexico: (1) those 

associated with spaces near houses, (2) those associated with 

plots, and (3) those associated with forests and mountains; each 

has different levels of management intensity. These agroforestry 

systems commonly found in Mexico contribute to 15 different 

primary uses, most importantly, food (especially fruits), forages 

and medicines, ornamentals, construction materials, energy, 

alcoholic beverages, fibers, resins, and latex.

Also relevant for considering the role of agroforestry in land 

use and climate change mitigation is the land tenure system, 

which is unique to Mexico and differs from most other countries 

in Central and South America. A major land tenure reform 

favorable to common property management arose from the 

Mexican Revolution (1910–1920) (Bray et al. 2005), enabling 

the communal lands or ejidos to be established. For these reforms, 

the State effectively gave collective land entitlements to thousands of rural communities, resulting in more than 60 percent 

of Mexico’s forested land currently being under communal 

ownership (Bray et al. 2003, FAO 2010). The internal organization of an ejido allows for collective activities in communal 

lands and family-level management in individual parcels. In 

total, some 60 percent of the country’s forest resources are 

within communal lands where traditional agroforestry practices 

have been documented in at least 25 distinct indigenous groups 

scattered throughout the country, but mainly in the center 

and south (Boege 2009, Moreno-Calles et al. 2014). Notably, 

agroforestry systems in Mexico are primarily maintained at 

the individual-family scale. The new Agrarian Law of 1992 

involved several changes in land tenure in Mexico and its 

Federal support. The most significant change was the possibility to obtain freehold rights of the parcels, including their 

privatization (Agrarian Law, Articles 81 and 82).

Regional Adoption Trends and Constraints

Mexico consists of eight dominant ecosystem types, in addition 

to areas dominated by pasture or agricultural crops (fig. 8.1). 
Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions 115

Figure 8.1. Distribution of major ecosystems in Mexico. (Modified from INEGI 2012).

In this chapter, we focus on a subset of these ecosystems when 

describing the dominant trends and constraints in adopting 

agroforestry systems: tropical wet forests, tropical montane 

cloud forests, and tropical seasonal dry forest.

Tropical Wet Forests

Tropical wet forests are located close to the equator, where the 

climate is predominantly wet, with an average of more than 

2000 millimeters (mm [79 inches]) of rainfall per year and uniformly high temperatures, between 20 and 35 °C. In Mexico, 

tropical wet forests occur primarily in the States of Chiapas, 

Tabasco, Oaxaca, and Veracruz and are characterized by a high 

diversity of plant and animal species, and by large trees—from 

50 to 70 meters (m [165 to 230 feet]) tall—often supported by 

strong buttresses at the base of the trunk that help to stabilize 

them in the shallow forest soils and with abundant vines and 

lianas attached to their trunks. Another distinctive characteristic 

of tropical wet forests is the high degree of vertical stratification, 

often composed of several layers of vegetation, each one quite 

diverse in plants and animals (Rzedowski 1978).

Cacao. The cacao tree (Theobroma cacao), which grows under 

the canopy of tropical wet forests, has been cultivated by 

several cultures in Mexico and Central America for the past 

three millennia. Considered one of the oldest agroforestry 

systems in the world, the earliest evidence (1900 B.C.E.) of 

cacao cultivation traces to the pre-Olmec cultures known as 

the Mokaya. Mesoamerican people, including the Mayans and 

Aztecs, used the seeds of cacao fruit to make a beverage known 

as xocol lt, a Nahuatl word that means bitter water (McNeil et 

al. 2009, Young 1994). Table 8.1 provides an example of the 

extent and production of cacao agroforestry plantations in the 

State of Chiapas. Cacao trees can be productive for up to 50 

years, and the older the cacao trees in the plantation are, the 

Table 8.1. Surface area planted and harvested with cacao 

in the municipalities in the State of Chiapas in 2010, by 

municipality.

Municipality

Surface area 

planted 

(ha)

Surface area 

harvested

 (ha)

Production

(tons)

Pichucalco 8,020 7,918 3,374

Palenque 932 902 391

Tapachula 10,159 10,159 4,415

Tuxtla Gutierrez 620 620 210

Total 19,731 19,599 8,390

ha = hectares.

Sources: SIAP (2010); c.f. Zequeira-Larios (2014).
116 Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions

higher the biodiversity. A 30-year-old plantation can hold up 

to 500 individual plants per hectare, representing 23 families, 

30 genera, and 32 species, and a 50-year-old plantation can 

hold 1,238 individuals representing 24 families, 40 genera, and 

44 species. Cacao plantations are not only very important as 

biodiversity conservation areas but also as sources of timber 

products, fruits, and many tree species in general, and, above 

all, because of their ancestral origin as a cultural symbol in the 

tropical regions of Mexico (Ramirez-Meneses et al. 2014). A 

common practice today in response to declining cacao prices is 

the planting of valuable timber species such as Cedrela odorata

within cacao plantations as a means of boosting revenues. 

Cacao trees are currently threatened by Moniliophthora roreri, 

which causes frosty pod rot, a highly destructive disease found 

in 11 countries in South and Central America.

Agroforestry systems based on cacao production at the national 

level in Mexico are declining (fig. 8.2), and often then systems 

are replaced by more intensive agricultural crops or livestock 

production. However, there is interest in stimulating cacao 

production in Tabasco, because it was Mexico’s first global 

exporter of cacao.

Figure 8.2. Comparative historical data on the national production of cacao in Mexico, 2000 to 2010. (SIAP 2010; c.f. 

Zequeira-Larios 2014).

Homegardens. The homegarden is an integral part of smallholders’ production strategies in Mexico. Although they can be 

found throughout all of the Mexico, homegardens are particularly 

common in the tropical wet forest zone. Homegardens tend to 

harbor high levels of biodiversity, which are maintained and 

enriched by farmers’ practices, particularly plant and seed 

exchange (DeClerck and Negreros-Castillo 2000). Most homegardens are multipurpose, providing goods for home consumption, 

sales, environmental services, and experimentation and learning 

(Aguilar-Stoen et al. 2009). From a climate change perspective, 

homegardens provide an important strategy for increasing the 

resilience of small farms to a changing environment by supporting 

a diversity of plant (and often animal) species adapted to diverse 

conditions. Because homegardens often have a high proportion 

of woody biomass relative to agricultural systems dominated 

by annual crops, they also generally have higher potential for 

carbon sequestration.

Vanilla. Vanilla (Vanilla planifolia) is a nontimber forest product that has been managed in Mexico since pre-Hispanic times, 

especially among the Totonaca indigenous group in the region 

of Totonacapan (the States of Puebla and Veracruz) (Barrera-Rodriguez et al. 2009). Four agroforestry production systems 

have been recognized within Totonacan management strategies, 

each having different management intensities and diversity and 

composition of tree species: (1) secondary forests (traditional), 

(2) shade tree systems with Erythrina and Gliricidia sepium

(technified), (3) shade tree systems with orange trees (Citrus x 

aurantium L.) (semitechnified), and (4) living fences (with 50 

percent shade) (Barrera-Rodriguez et al. 2009, Hernandez-Hernandez 2011, Sanchez et al. 2001). Vanilla is cultivated within 

each of these four agroforestry production systems in the States 

of Chiapas, Oaxaca, Puebla, and Veracruz and, to a lesser 

extent, in Hidalgo, Michoacán, Quintana Roo, and San Luis 

Potosi (Damiron 2004, Hernandez-Hernandez 2011, Lopez et 

al. 2009). Consequently, vanilla-based shade-tree agroforestry 

systems typically support a high degree of species and structural diversity, which contributes to maintaining species diversity 

and biogeochemical cycling and providing multiple ecosystem 

services (Arroyo-Rodriguez et al. 2008, Hernandez-Hernandez 

2011, Lopez et al. 2009, Soto-Arenas 2006). Today, vanilla is 

primarily produced as part of subsistence-based agroforestry 

systems, using a range of techniques, from traditional to more 

intensive-technical. The latter is characterized by greater use of 

chemicals to control pests, disease, and weeds and also by the 

use of tree species as trainers, particularly from the Leguminosae family (Gliricidia spp. and Erythrina spp.). The traditional 

system is characterized by the use of secondary forest species 

that regenerate naturally, or, in slightly more intensive systems, 

use of citrus trees that have been planted. Overall, vanilla 

production has been declining—from 445 tons in 1993 to 189 

tons in 2002—largely because of the increased instability in 

the market price of green vanilla in recent years combined with 

lack of economic incentives in recent years (Barrera-Rodriguez 

et al. 2011); consequently, producers have been developing 

alternative production activities (Toussaint-Samat 2002).

Silvopasture and agrosilvopasture. Extensive cattle production 

throughout Mexico and many tropical regions in Latin America 

has led to the conversion of natural tropical forest to pasture. 

The integration of trees within pastures, referred to as silvopasture systems, has, in some cases, evolved naturally as farmers 

protect trees that are valued particularly for their shade, food, 

or other products. In other cases, this integration has been 

promoted specifically as a means for improving environmental 
Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions 117

quality and sustainability. Silvopastoral systems improve cattle 

raising because of high-quality forage provided by the trees, 

shade provided by timber trees, and the reduced costs of using 

live fences. Silvopastoral systems also increase the diversity 

of ecosystem services provided by cattle-raising systems, such 

as carbon sequestration, mitigation of methane emissions, and 

fixation of atmospheric nitrogen. In some Mexican States, such 

as Chiapas, knowledge and use of fodder trees and shrubs play 

an important role in the design of more environmentally sound 

cattle-raising systems and also provide significant income to 

farmers. Within the region of the Selva Lacandona, Chiapas, 

local people cultivate a total of 28 fodder species, representing 

16 botanical families. In addition to being used for forage, most 

of the species are also used for shade, food, fuel wood, live 

fences, medicine, and construction (Jimenez-Ferrer et al. 2008).

Tropical Montane Cloud Forests

Also known as fog forest and, in Spanish, as bosque mesófilo 

de montaña, tropical montane cloud forests are broadly characterized as ecosystems that experience frequent and persistent 

fog, or low-lying clouds. Because of its geographical location, 

this forest type is considered to be a transitional vegetation 

between the temperate forest and the tropical deciduous dry 

forest along elevational gradients. It is comprised of deciduous 

and evergreen trees and is covered with brilliantly colored orchids, 

bromeliads, mosses, and lichens. Although cloud forests occupy 

less than 1 percent of the country’s land area, they are home to 

10 to 12 percent of plant and animal species, many of which are 

endemics. More than 50 percent of this type of forest has been 

transformed to other land uses in Mexico during the past few 

decades, and the cloud forest is considered the most endangered 

type of tropical forest worldwide. Agroforestry production 

is an important alternative in regions of cloud forest that can 

help insure the socioeconomic wellbeing of landowners while 

simultaneously helping to protect these endangered forests 

by creating habitat for forest species, increasing connectivity, 

and minimizing edge effects along forest remnants. The main 

agroforestry production systems that are employed in regions 

of cloud forest in Mexico and that are capable of balancing 

conservation and development concerns include coffee, chamaedorea palm, pita, and pepper spice. These systems are discussed 

in more detail below.

Shade coffee. In areas with tropical seasonal dry forest and 

cloud forests, one of the most important agroforestry systems 

has been shaded coffee plantations. Mexico historically has 

been an important producer of higher quality shade coffee and 

currently occupies ninth place in production worldwide (Financiera Nacional de Desarrollo 2014). Coffea arabica dominates 

production in the country (97 percent of cultivated area) and 

grows best between 600 and 1200 m (2,000 to 4,000 ft) above 

sea level. Coffee is currently the most important export crop in 

Mexico, after grains, and is cultivated on 690,000 ha (1,700,000 

acres [ac]) spread across 12 States (SAGARPA 2012). Production by some 500,000, mostly small (90 percent less than 1 ha 

[2.5 ac]) and indigenous (66 percent of municipalities), coffee 

growers provides a source of income for 3 million Mexicans.

The traditional and commercial shade polycultures that dominate 

(90 percent of cultivated area) coffee production in Mexico 

(Escamilla et al. 1994; Moguel and Toledo 1999) include a mix 

of native and introduced tree species that are typically nitrogen 

fixers and/or are useful commercially. These species include 

Citrus spp., banana (Musa spp.), rubber (Castilla elastica), 

pepper (Pimenta dioica), cedar (Cedrela odorata), jinicuil or 

chalahuite (Inga spp.), and colorin (Erythrina spp.). Coffee 

agroforestry systems are often enriched with chamaedorea 

palms, pepper trees, and pita, but in extreme cases such as the 

Tosepan cooperative Titataniske in the State of Puebla, such 

enrichment can reach 69 plant species per parcel or 250 to 300 

plant species in total (Toledo and Moguel 2012). Because of 

the high biological diversity (an average of 29 tree species per 

farm) (Lopez-Gomez et al. 2008) and concomitant structural 

diversity, these agroforestry systems help conserve an important proportion of the fauna and flora of tropical montane 

cloud forests (Manson et al. 2008; Moguel and Toledo 1999; 

Philpott et al. 2008). These benefits, and associated ecosystem 

services (Jose 2009), have helped make Mexico a pioneer in 

the production of organic coffee (10 percent of production 

area), a recognized leader in other types of certification such 

as fair trade, and a target of payments from national and local 

programs focused the conservation and restoration of key 

ecosystem services.

Coffee production in Mexico has suffered since the early 

1990s, with the collapse of international coffee agreements that 

regulated coffee production and stabilized prices and with the 

elimination of INMECAFE, which provided technical training 

and financing to growers and also collected, processed, and 

commercialized the coffee of the nation’s coffee growers. 

Recurring international cycles of overproduction and low 

prices have hit Mexican growers hard (Manson et al. 2008). 

Coffee production in Mexico is also suffering because of pests 

and diseases such as broca, nematodes, and La Roya. Both the 

quantity and quality of coffee production may decline further 

because of the warmer, drier weather conditions expected under 

current scenarios of global climate change, unless growers 

implement measures to mitigate or adapt to these changes (Gay 

et al. 2006; Laderach et al. 2011). Two consequences of these 

trends have been a shift to resistant, more productive, varieties 

that require more agrochemicals and less shade cover, and 

increased rates of conversion of shade coffee plantations to 

other land-use systems, especially sugarcane or pasture, which 

typically lead to greater environmental degradation and reduce 

climate change mitigation potential.
118 Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions

Chamaedorea palm. The chamaedorea palm is one of the 

principal nontimber forest products primarily found in cloud 

forest ecosystems in Mexico and comprises 37 percent of the 

international market. Mexico is considered a center of diversification. Of the 130 species of Chamaedorea known on the 

American continent, about 50 are found in Mexico, of which 

14 are native species. Planted populations of these palms do 

not produce seed because of a lack of pollinators, and therefore 

seed must be collected from natural populations found in 

forest ecosystems, an important factor in the conservation of 

forests where the plant is found. Chamedorea palm leaves 

(particularly from Chamaedorea elegans) have been exported 

as an ornamental internationally, especially to the United 

States, for more than a century, but the rate of exportation 

increased greatly starting in the 1940s. Palm populations 

overall have remained stable, although overexploitation, habitat 

destruction, and land-use change threaten populations in some 

parts of Mexico. Diverse initiatives by the National Forestry 

Commission (CONAFOR) of Mexico (CONAFOR 2014) and 

various nongovernmental organizations (NGOs) have promoted 

the cultivation of palm in forested areas and also as part of 

agroforestry systems, such as shade coffee, especially in the 

States of Chiapas, Oaxaca, and Veracruz. Both the chameadorea 

palm and pita (see details in the following section) grow well in 

as part of more intensively managed agroforestry systems (e.g., 

shade coffee), and they are especially important in providing a 

safety net for poor farmers to rely on when production of other 

subsistence or cash crops is lower than anticipated (Marshall et 

al. 2006).

Pita. Pita (Aechmea magdalenae) is a highly resistant fiber 

obtained from a terrestrial bromeliad, originally used in 

pre-Hispanic times primarily for fishing nets; more recently, 

it has been popularized through its use in artisan charreria

with decorative borders in pita, especially in Chiapas and 

Oaxaca. With increasing demand, rural communities began to 

domesticate the pita plant by collecting cuttings to plant within 

their gardens, coffee and fruit plantations, and nearby forest 

plots. Productivity is estimated at 15 to 25 kg/ha (13 to 22 lb/

ac), representing a value of $4,500 to 10,000 Mexican pesos/ha 

($100 to $220 U.S. dollars/ac), which is greater than the value of 

coffee or cattle. Thus, the pita provides an important means of 

economic diversification and alternative income source when 

prices of other products are low, and it contributes to conservation of remaining forest patches within agricultural landscapes. 

Annual production of pita in Mexico varies between 30 to 40 tons.

Pepper tree. The pepper tree (Pimenta dioica), also known 

as the pepper spice, grows throughout Central America, the 

Caribbean, northern South America, and Mexico. Trees typically 

reach a height of 6 to 10 m (20 to 30 ft) and grow as isolated 

trees with open pastures, where they are valued for their shade. 

They are also integrated as part of home gardens and with 

other crops (e.g., orange, banana, cacao, coconut), where they 

help control weeds. The pepper spice was originally used in 

pre-Hispanic times and continues to be a valuable condiment 

internationally, with demand for dry pepper and essential oils 

increasing progressively. It is an important crop grown within 

coffee plantations in the States of Campeche, Chiapas, Oaxaca, 

Puebla, Tabasco, and Veracruz. Production in Mexico between 

1990 and 2000 increased from 868 to 4,980 tons, with most 

of this product exported internationally. Mexico is the second 

major producer and exporter of pepper worldwide, after Jamaica.

Tropical Seasonal Dry Forest

Tropical seasonal dry forests are characterized by pronounced 

seasonality in rainfall. The many deciduous species in these 

forests are adapted to the seasonal absence of rainfall, and plant 

species abundance is nurtured by the warm temperatures. Tropical seasonal dry forests have a high diversity and endemism 

(Trejo and Dirzo 2000). In the neotropics, these forests reach 

their northernmost distribution in Mexico (across the States of 

Baja California, Sonora, Sinaloa, Tamaulipas, all the way down 

to Chiapas) (Cairns et al. 1995, Ceballos and Garcia 1995, 

Lopez-Barrera et al. 2014).

A large portion of tropical dry forest was lost in the 1970s, 

when the Mexican Government supported the clearing of 

these forests along the Pacific coast of the State of Jalisco to 

be used for agriculture, cattle ranching, tourism, and housing 

uses (Romero-Duque et al. 2007). By 1980, human use had 

eliminated 44 percent of the original area of tropical dry forests 

in Mexico. Some of the human uses included converting the 

forests into grasslands for cattle grazing, employing slash-andburn agriculture, and harvesting wood for fuel (Galicia et al. 

2008). It is also important to note, however, that some of these 

pasture-based land-use practices may be considered agroforestry silvopastures for cases in which trees comprise integral 

components of the pastures, and slash-and-burn agricultural 

systems may be considered agroforestry if sufficient fallow 

periods and/or preservation of isolated trees within crop fields 

allow for the maintenance of permanent woody vegetation 

cover during longer periods.

Some tropical regions in Mexico, particularly those with dry 

forest, are used as silvopastoral systems, in which cattle forage 

on small trees and, during the dry season, on leaves and fruits 

that have fallen on the ground. The forage quality, in general, is 

higher in pastures. For example, in the Sierra de Manantlan, 19 

species (herbs, shrubs, and trees) are used as forage, although 

in this silvopastoral system, the Gramineae species produced 

higher biomass per square meter, and Verbesina greenmanii, 

Leucaena esculenta, and Acacia riparia showed higher nutrient 
Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions 119

content. On the other hand, two layers—trees and herbs—in the 

tropical dry forest might produce more biomass than grassland 

alone (Montano et al. 2003), while potentially providing other 

diverse products, such as pitayas, honey, and spices, such as 

oregano and candelilla.

Potential Carbon Sequestration From Use of 

Agroforestry in Mexico

Many different agroforestry systems occur in Mexico; however, 

only a few systems involve large-scale production of products 

that are supported under Government incentives or programs 

(e.g., shade coffee, cacao). In terms of total area covered and 

potential for contributing to climate change mitigation and food 

security, these other more traditional agroforestry systems are 

extremely important. Table 8.2 presents a summary of studies 

that have quantified contributions of different major agroforestry systems to carbon storage in Mexico, including comparisons 

with available global estimates and studies conducted in other 

Central American countries. Table 8.3 presents an overview of 

the distribution of major commercial agroforestry systems (e.g., 

shade coffee, cacao, and vanilla) by State in Mexico.

Table 8.2. Carbon storage in different agroforestry systems. 

System Location Other characteristics Carbon T/ha

Agrosilviculturea Global synthesis Humid tropical lowlands 39–102

Silvopasturea Global synthesis Dry tropical lowlands 39–195

Silvopasturea Global synthesis Humid tropical highlands 133–154

Corn fields with treesb Chiapas, Mexico 3.7 years old 127.9

Taungya (6.8 years)b Chiapas, Mexico 6.8 years old 109.4

Natural fallow (acahual)b Chiapas, Mexico 23.7 years old 117.6

Improved fallow (acahual)b Chiapas, Mexico 7.3 years old 150.1

Homegardenc Veracruz, Mexico Citrus + coffee 40.5–73.2

Homegardenc Veracruz, Mexico Citrus + banana 32.6–59.0

Homegardenc Veracruz, Mexico Citrus + coffee + banana 43.4–77.3

Homegardenc Veracruz, Mexico Citrus + coverage 37.9–44.8

Homegardenc Veracruz, Mexico Citrus + pelibuey sheep 63.4–94.7

Pasturec Veracruz, Mexico 1.4–2.1

Shade coffee, conventionald Costa Rica 69.0

Shade coffee, organicd Costa Rica 98.0

Improved fallowe Chiapas, Mexico Low tropical agroclimatic zone 140.8

Taungyae Chiapas, Mexico Low tropical agroclimate zone 140.8

Pastures with scattered treese Chiapas, Mexico Low tropical agroclimate zone 129.3

Pastures with live fencese Chiapas, Mexico Low tropical agroclimate zone 118.6

Pastures without treese Chiapas, Mexico Low tropical agroclimate zone 71.5

Taungyae Chiapas, Mexico High tropical agroclimatic zone 173.9

Improved fallowe Chiapas, Mexico High tropical agroclimatic zone 148.3

Traditional fallowe Chiapas, Mexico High tropical agroclimatic zone 157.5

Inga-shade organic coffeee Chiapas, Mexico High tropical agroclimatic zone 194.0

Polyculture-shade organic coffeee Chiapas, Mexico High tropical agroclimatic zone 151.9

Polyculture-shade nonorganic coffeee Chiapas, Mexico High tropical agroclimatic zone 173.2

Traditional maizee Chiapas, Mexico High tropical agroclimatic zone 109.7

T/ha = teragrams per hectare.

a

 Winjum et al. (1992); Brown et al. (1993); values standardized to a 50-year rotation and represent total carbon storage in vegetation and soils. 

b Roncal-Carcia[Garcia? As in Lit. Cit. entry? Which spelling is correct?] et al. (2008), modified by Casanova-Lugo et al. (2011); total carbon storage in vegetation and soils.

c

 Callo-Concha et al. (2004), modified by Casanova-Lugo et al. (2011). Carbon storage in aboveground vegetation and litter.

d Hager (2012); total aboveground and belowground carbon.

e

 Soto-Pinto et al. (2010); total aboveground and belowground carbon.
120 Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions

Table 8.3. Current distribution and production of dominant agroforestry systems (shade coffee, cacao, and vanilla) in Mexico by 

State. 

State Coffee area

(ha)

Coffee value 

(1,000s of pesos)

Cacao area

(ha)

Cacao value 

(1,000s of pesos)

Vanilla area

(ha)

Vanilla value 

(1,000s of pesos)

Chiapas 259,315 2,508,647 20,299 306,840 0 0

Veracruz 147,384 1,791,264 0 0 740 26,798

Oaxaca 142,766 481,808 0 0 145 4,195

Puebla 72,175 645,347 0 0 71 1,960

Guerrero 47,190 284,106 237 1,084 0 0

Hidalgo 25,821 147,266 0 0 0 0

Nayarit 17,678 129,113 0 0 0 0

San Luis Potosi 17,154 19,769 0 0 97 999

Jalisco 3,835 30,176 0 0 0 0

Colima 2,378 13,051 0 0 0 0

Tabasco 1,040 4,670 40,783 708,477 0 0

Mexico 479 2,085 0 0 0 0

Queretaro 270 2,066 0 0 0 0

Total 737,485 6,059,368 61,319 1,016,401 1,053 33,952

Millions of dollars 459 77 3

ha = hectares.

Source: SAGARPA (2013).

Overview of Existing Policies

In 1997, the National Forestry Commission of Mexico 

(CONAFOR) established the Commercial Plantations Development Program (PRODEPLAN). This program included support 

for establishing agroforestry systems as part of its primary goal 

of expanding commercial forestry plantations in Mexico. Between 

2000 and 2010, 83,172 ha (205,522 ac) of agroforestry plantations 

were established with CONAFOR’s funding support; however, 

the classification of these systems was based purely on the 

plantation density (e.g., 600 trees/ha [1,482 trees/ac]) without 

specifying the types of agricultural or livestock components 

that are managed in combination with forestry production. 

Thus, available information on areal extent of implementation 

should be interpreted cautiously (CONAFOR 2014).

The target goal of expanding forest plantations was not fully 

realized in this program, which was largely attributed to 

landowner unwillingness to invest the resources when financial 

returns occur on such long time scales. This lack of success led 

to agroforestry systems being included within PRODEPLAN 

in 2011, focusing on those systems having a woody component 

with merchantable timber as an alternative to stimulate the 

establishment of forestry plantations. The modification made 

to the operational rules for PRODEPLAN, for the first time, 

identified the specific agricultural, livestock, and forestry components included in the agroforestry system and the required 

field verification that the system was implemented according to 

the original proposal.

Between 2011 and 2012, 3,852 ha (9,518 ac) of agroforestry 

systems were supported under this program, and, in 2012, 

another 182 ha (450 ac) were established. Relative to the total 

number of hectares planted and resources distributed under this 

program, however, the proportion dedicated to agroforestry 

systems remains small. Figure 8.3 shows the distribution of 

agroforestry systems by State during the period from 1997 to 

2012 that were implemented through CONAFOR. The program 

for the Production and Commercialization of Non-Timber 

Forest Products also provides support to certain agroforestry 

systems. Table 8.4 presents the agroforestry systems that have 

been supported as part of this new category of Agroforestry 

Plantations within PRODEPLAN, by bioclimatic region.

The proposal “Agroforestry-Timber Systems Most Appropriate 

for Mexico” calls for future CONAFOR support to target the 

following four systems: (1) taungya, (2) alley cropping, 

Figure 8.3. Distribution of agroforestry systems, by State, 

established with support from CONAFOR’s PRODEPLAN program between 1997 and 2012. (CONAFOR 2014).
Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions 121

Table 8.4. Agroforestry-timber systems established in tropical regions in Mexico since 2011 under Comisión Nacional Forestal’s 

Plantation Agroforestry category, by climatic zone. (1 of 2) 

State Surface area (ha) Agroforestry system (tree species) Associated plant species

Tropical zone

Guerrero 25

25

60

50

50

50

100

124

50

169

1. Cedrela odorata, Swietenia macrophylla, Cordia eleagnoides

2. Cedrela odorata

3. Cedrela odorata, S. macrophylla

4. Cedrela odorata, S. macrophylla

5. Cedrela odorata, S. macrophylla

6. Cedrela odorata, S. macrophylla

7. Cedrela odorata, S. macrophylla

8. Cedrela odorata, S. macrophylla

9. Cedrela odorata, S. macrophylla

10. Cedrela odorata, S. macrophylla

1. Coconut

2. Agricultural crops

3. Corn, beans

4. Corn

5. Corn, beans, pasture

6. Corn, beans, pasture

7. Corn, beans, pasture

8. Corn, beans, pasture

9. Corn, beans, pasture

10. Corn, beans, pasture

Hidalgo 100 Cedrela odorata Coffee

Quintana Roo 71

5

1. Cedrela odorata, S. macrophylla

2. Cedrela odorata, S. macrophylla

Corn

Chiapas 20

6

1. Cedrela odorata, Tectona grandis

2. Tectona grandis, Tabebuia donnell-smithii, Tabebuia rosea

Cacao

Mango

Oaxaca 42 S. macrophylla, Tabebuia donnell-smithii, Cedrela odorata Coffee

Tamaulipas 162

118

1. Eucalyptus camaldulensis

2. Gmelina arborea, Tectona grandis, Eucalyptus camaldulensis

Sorghum

Pasture

Puebla 50 S. macrophylla Forages

Tabasco 27

83

1. Cedrela odorata

2. Eucalyptus spp.

1. Elaeis guineensis

2. Brachiaria brizantha

Veracruz 25 Gmelina arborea Leucaena spp.

Michoacan 50 Gmelina arborea, Tectona grandis, Eucalyptus camaldulensis Leucaena spp.

Nayarit 25

35

25

1. Tabebuia donnell-smithii, Tabebuia rosea

2. Eucalyptus spp.

3. Tabebuia donnell-smithii, Gmelina arborea, Cedrela odorata

1. Pasture

2. Leucaena spp.], Brosimum 

alicastrum, Guasima spp.,

3. Leucaena spp.

Temperate and semiarid zones

Guanajuato 50

200

1. Pinus greggii

2. Pinus greggii

1. Corn, beans

2. Corn, beans

Tlaxcala 30

79

1. Pinus pseudostrobus, Pinus montezumae

2. Pinus pseudostrobus, Pinus montezumae

1. Rye, corn, basic grains

2. Wheat, corn

Puebla 22 Pinus pseudostrobus Coffee

San Luis Potosi 100 Prosopis spp. Opuntia spp.

Nuevo Leon 56

53

36

67

75

1. Prosopis glandulosa

2. Prosopis glandulosa

3. Prosopis glandulosa

1. Prosopis glandulosa

2. Prosopis glandulosa

1. Pradera

2. Sorghum (forage), vegetable crops

1. Forage

2. Forage

3. Forage

Sonora 44 Prosopis spp. Native grasses

Queretaro 20

25

1. Pinus greggii

2. Pinus greggii, Prosopis laevigata

1. Rye

2. Alfalfa

ha = hectares.

Source: CONAFOR-UNACH (2013).

(3) mixtures of perennial crops and trees, and (4) tree plantations 

with pasture and livestock (see details in table 8.5). Additional 

criteria for consideration include that the system should be 

established under areas having good agroecological conditions 

and with fast-growing trees with timber potential to ensure 

both maximum ecological and financial success for interested 

producers and to reduce costs to the program (CONAFOR 

2014).

As part of its proposal for Agroforestry-Timber Systems Most 

Appropriate for Mexico, CONAFOR conducted a study to 

identify and prioritize potential areas for establishing agroforestry 

systems throughout the entire country (CONAFOR 2014). 

Areas with the following characteristics were excluded from 

the analysis: areas higher than 3000 m (9,842 ft) above sea 

level, areas susceptible to flooding, natural protected areas, 

areas with severely saline or sodic soils, areas with slopes of 
122 Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions

Table 8.5. Principal characteristics of the proposed agroforestry-timber systems for Mexico. 

Agroforestry system Principal characteristics

Taungya Temporal combination of trees with agricultural crops; trees are planted with uniform spacing; crops 

are grown while there is sufficient light; crops with greater shade tolerance may be substituted as the 

plantation develops.

Alley cropping Permanent mixture of crops or pasture in alleys; the timber trees can be established in lines of different sizes; the pasture can be for cutting or grazing.

Mixtures of perennial crops and trees Permanent combination of agricultural crops and timber trees that may (or may not) provide shade for 

the crops; examples of tree species include rubber, coffee, cacao and coconut.

Tree plantations with pasture and livestock Permanent combination of timber trees with dispersed shade within pasture maintained for livestock.

Source: CONAFOR-UNACH (2013).

more than 25 percent (more than 20 percent for tropical lands), 

arid zones with less than 300 mm mean annual precipitation 

(MAP), tropical zones with less than 800 mm MAP, temperate 

zones with less than 600 mm MAP, polygons of less than 100 

ha in size, areas with thin soils or soils with rocky outcroppings 

(lithosols), and severely degraded lands. Application of these 

criteria resulted in a total surface area of 13.9 million ha (34.3 

million ac), distributed across 30 States, which were considered 

priority areas for agroforestry implementation as part of this 

study. The analysis (using a geographic information system) 

resulted in a total “potential” surface area for agroforestry of 

4 million ha (10 million ac), with nearly 86 percent concentrated in eight States (table 8.6).

Data from the States of Veracruz and Tabasco show that at 

least one of the most common 15 genera of agroforestry species 

were planted outside of established priority zones (fig. 8.4). 

Agroforestry systems were likewise established in areas where 

water scarcity was considered as a fundamental limitation and 

potential cause of failure of agroforestry systems (CONAFOR 

2014). CONAFOR’s recommendation is that future agroforestry programs target the priority areas (CONAFOR 2014).

Distribution of agroforestry species and priority areas based on 

elevational zones; e.g., Zone A (0 to 700 m above sea level), 

Zone B (700 to 1500 m above sea level), Zone C (1500 to 2200 

m above sea level), and Zone D (more than 2200 m above 

sea level) has been identified (CONAFOR 2014). Of the total 

area with high potential for agroforestry (i.e., 3.96 million ha 

[10 million ac]), the majority (82 percent) is located in Zone 

A, with 14 percent of the remaining area in Zone B and 4.5 

percent in Zones C and D. The most frequently used agroforestry woody species and associated crops for each elevational 

zone were coffee and cacao and corn, beans, oats, and pasture, 

respectively (table 8.7)

Table 8.6. Distribution of potential surface area for agroforestry 

systems in Mexico, by State. 

State Surface area (ha) Percent of surface area

Veracruz 1,403,500 35.3

Chiapas 414,871 10.4

Oaxaca 369,146 9.3

Tabasco 340,242 8.5

Guerrero 339.844 8.5

San Luis Potosi 214,664 5.4

Puebla 170,207 4.3

Nayarit 161,919 4.1

Quintana Roo 100,916 2.5

Michoacan 80,984 2.0

Campeche 65,981 1.7

Tamaulipas 57,533 1.4

Hidalgo 57,228 1.4

Yucatan 54,360 1.4

Jalisco 52,235 1.3

Mexico 46,991 1.2

Durango 17,3355 0.4

Chihuahua 13,610 0.3

Colima 10,353 0.3

Sinaloa 5,065 0.1

Morelos 3,315 0.1

Sonora 600 0.01

Nuevo Leon 83 0.002

Total 3,980,002 100

Source: CONAFOR 2014.

Figure 8.4. Comparison of identified agroforestry priority areas 

(orange) for the States of Tabasco and Veracruz with the areas 

where at least one of the most common 15 genera in agroforestry 

systems were planted (green). (CONAFOR 2014).
Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions 123

Table 8.7. Potential surface area for major agroforestry crops, by altitudinal zone. 

Crop

Surface area (hectares)

Zone A

(0–700 m) 

Zone B

(700–1500 m)

Zone C

(1500–2200 m)

Zone D

(> 2200 m) Total

Coffee 2,182,307 377,711 85,296 — 2,645,314

Chocolate 545,893 150,272 38,377 — 734,542

Corn 3,156,853 549,751 155,597 21,831 3,884,032

Beans 2,972,847 469,592 115,596 19,812 3,577,847

Oats 183,381 61,677 46,270 8,584 299,912

Pasture 3,193,381 546,487 142,819 20,795 3,903,482

Note: Zone elevations (in meters) in parentheses.

Source: CONAFOR 2014.

Payments for Ecosystem Services Programs

Agroforestry production in Mexico has also been strengthened 

by the rapid growth of programs making payments for ecosystem 

services (PES). These programs were originally envisioned as 

a means for conserving and restoring the country’s endangered 

forest and water resources, linked through the multiple services 

provided by these ecosystems (Manson 2004, Mora 2015, MunozPina et al. 2011). There is also a growing interest for using PES 

programs to address the socioeconomic and cultural problems, 

which may be limiting their effectiveness in achieving environment goals (Alix-Garcia et al. 2012, Munoz-Pina et al. 2011). 

Mexico’s national PES program was established in 2003 through 

the redistribution of 2.5 percent of water-concession payments 

nationwide from the National Water Commission to CONAFOR. 

These funds were used to establish 5-year contracts with land -

owners in key watersheds throughout the country for providing 

hydrological services. Starting in 2004, payments were authorized 

for additional services, including carbon sequestration, biodiversity 

conservation in forest plots, and improvement of shade cover 

in agroforestry systems (mostly shade coffee and cacao farms). 

Payments for carbon sequestration were eliminated in 2006. 

The national PES program is now one of the largest in the world, 

having made more than $650 million in payments covering 

4.16 million ha during the period from 2003 to 2013 (table 8.8).

Table 8.8. Beneficiaries, area, and amount paid by year in 

Mexico’s national program making payments for ecosystem 

services. 

Year Number of 

beneficiaries

Area

(thousands of ha)

Amount paid

(millions of pesos)

2003 272 127 192

2004 578 215 388

2005 302 196 310

2006 315 146 232

2007 1,447 610 1,061

2008 1,114 462 982

2009 693 502 1,096

2010 688 509 1,116

2011 558 465 980

2012 747 567 1,222

2013 637 471 1,006

ha = hectares.

Source: CONAFOR (N.d.).

The proportion of payments to lands in the category of PES 

including agroforestry systems has been growing and comprises 

26 percent of all areas that have been included in the national 

program to date (table 8.8). To receive such payments, farmers 

with agroforestry production need to show that their shade 

cover is diversified and composed of native tree species and that 

cattle and other grazing animals are not part of the production 

system. Most payments have been made to shade coffee farms, 

followed by cacao, vanilla, and the chamaedorea palm.

Reducing Emissions From Deforestation and Forest 

Degradation

According to CONAFOR’s “Terms of Reference for the 

Operation of REDD+” (CONAFOR [N.d.]), one objective of 

REDD+ in Mexico is “to promote the establishment of agroforestry and silvopastoral systems, as well as other innovative 

production schemes, that simultaneously enhance food security 

of local people and the restoration of degraded areas.” Within 

this program, agroforestry is defined as “a management system 

focusing on agricultural production that integrates forestry 

activities through productive reforestation and the management 

of degraded areas, with the goal of obtaining diverse benefits 

such as food security, production diversification, ecosystem 

connectivity, biodiversity conservation, among other ecosystem 

products and services.”

Several special programs known as “early actions REDD+” 

have been launched recently in Mexico. In 2013, such programs 

were established in Campeche, Chiapas (Lacandon Forest), 

Oaxaca, Quintana Roo, and Yucatan. These programs support 

the establishment of agroforestry systems (crops plus trees) 

and silvopastoral systems (mostly live fences). In 2014, a 

new special program was launched in the coastal region of 

Michoacan to support the establishment and management of 

both agroforestry and silvopastoral systems. The only special 

programs that include the production of tree seedlings are the 

ones for Campeche, Chiapas, and Oaxaca. These special programs are administrated through the Department of Community 

Forestry of CONAFOR. The special programs were established as 

a strategy to mitigate climate change, join biological corridors, 
124 Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions

provide socioenvironmental benefits, and slow down or stop 

deforestation. So far, these special programs are applied only in 

the aforementioned States.

Constraints to Adoption and Implementation of Agroforestry Systems in Mexico

To a large extent, adoption of different agroforestry system 

depends on the cultural practices of the particular indigenous 

groups present in each region and on the climatic constraints 

of the different agroforestry crops (e.g., vanilla in Veracruz, 

avocado in Michoacán, cacao in Tabasco). Several major threats 

to the future continuation or expansion of agroforestry systems 

in Mexico include: (1) the reduction in species and agroforestry 

practices represented; (2) the loss of knowledge and/or abandonment of traditional agroforestry practices, a process related to 

the out-migration of young men and women, along with the 

aging and death of the farming populations; (3) agricultural 

intensification that results in a reduction or loss of the fallow 

period, the vegetative cover, and traditional crops, along with 

an increase in the use of machinery, agrochemicals, and annual 

crops; and (4) the rental or sale of private lands for development 

of intensive crops or residential homes (Moreno Calles 2013).

Another factor that potentially limits the expansion of agroforestry 

systems to new areas is the oftentimes inadequate alignment 

between support and resources available from the different 

institutions, especially because cattle ranching and agricultural 

activities that are promoted by many Government programs 

often result in the destruction of forest resources (Moreno Calles 

et al. 2013). Land tenure issues may also limit agroforestry expansion. For example, cattle ranching laws in Mexico manipulate 

the definition of stocking densities to circumvent the definition 

of small property in the redistribution of lands after the Mexican 

Revolution, resulting in the establishment of relatively large 

properties that are dedicated to cattle ranching and that do 

not generally favor the establishment of agroforestry or other 

production systems (Gonzalez-Montagut 1999).

To understand what factors influence decisions and motivations 

to adopt agroforestry practices, a survey of previous and current 

program participants was conducted (CONAFOR 2014). The 

following list includes some of the major findings from this 

study.

• The selection of a particular species to incorporate within 

agroforestry systems depended on familiarity, growth 

rates, market value, ease of propagation and management, 

multiple use options, interactions with crops, availability, 

recommendations from programs, and the environmental 

impacts. Although exotic species were previously favored, an 

increasing interest in working only with native species has 

recently emerged. In general, producers preferred a mixture 

of different species.

• In general, agroforestry projects were more useful to landowners when they were provided with information about the 

behavior and resource requirements for a variety of species 

and agroforestry designs, rather than when they were offered 

a single standard system. This approach enables landowners 

to choose which combination of species and systems best 

meets their available resources and needs.

• Even though agroforestry systems may be inherently profitable, 

the success of adoption was greatly enhanced when landowners received technical assistance that provided information about the management of tree species and agroforestry 

configurations, which often were unfamiliar. In particular, 

the involvement of local people as technicians and extensionists has proven to be a successful and low-cost method 

for promoting agroforestry systems and also for developing 

local capacities and human resources for disseminating 

agroforestry in the future.

• The primary four reasons for participation in CONAFOR’s 

agroforestry program were (1) to provide a source of employment (i.e., because the program paid landowners directly to 

participate) (24 percent); (2) to increase the production of 

trees in certain areas (19 percent); to improve the environmental conditions on the land (38 percent); and to improve 

the economic value of the land (19 percent). Two-thirds of the 

participants perceived a potential for obtaining an income 

from the harvest of the trees as a major benefit of the 

agroforestry system.

• Major problems identified by the CONAFOR participants 

included the lack of sufficient economic resources for investing in infrastructure, labor, etc. (43 percent); biophysical 

limitations, such as pests and disease, lack of rain, excessive 

temperatures, or steep slopes (31 percent); social problems, 

such as vandalism, damage to plants from people (19 percent); 

and institutional problems related primarily to complex and 

slow bureaucratic requirements (7 percent).

• The subsidies provided by CONAFOR were instrumental 

in determining adoption of the agroforestry practices; 

89 percent indicated they would not have established the 

practices without the subsidies. In addition, many were 

unwilling to implement management practices (e.g., 

thinning, road maintenance) because of their high cost and/

or labor requirements.

A broader analysis of 21 agroforestry projects in Central 

America and the Caribbean by Current et al. (1995) identified 

several underlying themes that emerged as important factors 

influencing the adoption of agroforestry practices, including:

• The management intensity that is economically attractive for 

farmers depends on the degree of scarcity of forest resources, 

the level of demand, the opportunity cost of alternative uses, 
Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions 125

the availability of labor and capital, and the production costs 

relative to the cost of available substitutes for the products 

and services provided by trees. For example, this study found 

that, in Panama, traditional extensive land-use systems (e.g., 

migratory agriculture or slash-burn-fallow) were profitable 

in areas where land was widely available, whereas in areas 

with limited land area, such as El Salvador or the highlands 

of Guatemala, more intensive management systems such as 

agroforestry were more common.

• The adoption of agroforestry systems by small famers 

is usually most successful when it occurs gradually (i.e., 

during a 5-to-10 year period), taking into account the food 

security and risk reduction needs, especially because these 

producers often have limited resources and management 

options. The focus should be on starting with a few farmers 

and on agroforestry systems that offer continuous benefits 

during long periods. Overall, acceptance and adoption of 

agroforestry practices were higher among larger landowners, 

largely because they were able to better adapt their available 

resources compared with small landowners.

Needs and Emerging Opportunities for 

Agroforestry in Mexico

The “Second Revision of the FAO Strategic Forestry Program 

2025,” conducted in 2013 in collaboration with the Autonomous 

University of Chapingo, Mexico, states that one of Mexico’s 

strengths is the potential of its ecosystems to sequester carbon, 

which can promote conservation of resources and alternative 

incomes for inhabitants of forested areas (CONAFOR-FAO 

2014). Despite important efforts, such as the recent PES programs, 

however, the generation of markets and access to international 

credit funds are still in their initial phases. The area incorporated within the PES programs for carbon, biodiversity, and 

agroforestry in 2007 was 64,835 ha (160,211 ac). The panel of 

experts felt that the current PES system does not constitute a 

true market, and they recommended that Mexico develop the 

PES programs so that the projects can become eligible for the 

global carbon credit markets. Regarding hydrologic services, 

the panel observed that payments are not linked with the quality 

or quantity of services provided, therefore becoming just a 

subsidy for not using the forest resources. In response to these 

suggestions, CONAFOR is in the process of revising its PES 

programs to facilitate greater contributions by public resources, 

international donations, and users of ecosystem services to 

maintain PES programs.

In terms of sustainable management, agroforestry systems are 

unique. Agroforestry systems can serve as an important source 

of income to poor rural communities and can provide a host of 

other important ecosystem services, such as carbon sequestration, 

habitat and biological corridors for wildlife, and scenic beauty 

(Beer et al. 2003, Jose 2009, Martinelli 2012, Moguel and 

Toledo 1999). Despite these many benefits, production via the 

principal agroforestry systems in Mexico is declining because 

of a host of problems, including disease, climate change, low 

profits, and abandonment (Bacon et al. 2008; Diaz-Jose et al. 

2013; Gay et al. 2006; Tucker et al. 2009). Such trends make 

these agroforestry systems vulnerable to conversion to other, 

more intensified land uses with a concomitant loss of ecosystem services. This trend is particularly apparent in States such 

as Veracruz, where high population densities and a tradition 

as a major producer of farm produce and cattle for the country 

have left only a small remaining fraction of undisturbed natural 

vegetation (less than10 percent). Some 7,000 ha (17,297 ac) 

of shade coffee were converted to other land uses in central 

Veracruz during the past decade alone (2000 to 2010) (Cabrera 

Garcia 2015). In this context, agroforestry systems such as shade 

coffee play an even more important role by providing about 35 

percent of the tree cover in mountainous regions of the State.

Major agroforestry systems in Mexico (table 8.3) are currently 

considered as crops and fall under the sole responsibility of 

the Secretariat of Agriculture, Livestock, Rural Development, 

Fisheries and Food (SAGARPA), thus facilitating shifts from 

shade coffee plantations to other crops (e.g., sugar cane) as a 

simple transition from one crop to another. On the other hand, 

the classification of cacao and shade coffee farms as crops also 

limits their inclusion in CONAFOR’s forestry programs, which 

are designed to help promote sustainable forestry or plantations 

and that provide landowners with financing of up to $8,000 

pesos/ha or around 20 times that for which they can currently 

receive in PES payments if they are within eligible areas. This 

situation has created a vacuum whereby neither SAGARPA 

(responsible for agricultural activities) nor CONAFOR 

(responsible for forestry activities) has a specific mandate 

within their mission or terms of reference to promote large-scale 

agroforestry practices.

To counteract these tendencies, a coalition of academics, NGOs, 

and regional decisionmakers is proposing a modification of 

national laws that would recognize and conserve the multiple 

cultural, socioeconomic, and ecosystem service benefits provided 

by agroforestry systems (Mora 2015). The proposed legal 

reforms would make land under agroforestry production a 

hybrid land use eligible to participate in all relevant SAGARPA 

and CONAFOR programs and thus provide additional financial 

incentives for this type of production system. Further, classifying 

agroforestry as a type of forestry system would provide additional 

legal protections, so that converting cacao or shade coffee 

into more intensified and simplified production systems as a 

means of short-term profit would become more difficult. Such 

changes would make their protection more likely in regional 

planning exercises. The program recently established under 

REDD+, called “Forests and Climate Change,” proposes to 
126 Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions

create a common technical agency that would operate across 

both SAGARPA and CONAFOR, with the goal of facilitating 

agricultural activities within forested landscapes (including 

agroforestry practices) with an overall focus on integrated 

landscape management. If successful, this program has the 

potential for significantly increasing climate change mitigation 

and adaptation contributions by agroforestry systems in Mexico.

Key Findings

• Many agroforestry systems practiced in Mexico today are 

derived from traditional land-use systems developed by 

indigenous people over long periods of time and thus are 

well adapted to the local climate and biophysical conditions. 

• Agroforestry practices in Mexico provide opportunities for 

sequestering and storing larger amounts of carbon compared 

with other agricultural systems, such as pastures and crops.

• Existing policies in Mexico often do not adequately consider 

agroforestry practices as part of the country’s programs that 

address the challenges of sustainable land-use practices and 

climate change, largely because these systems are outside 

the mission of the main Government agencies responsible 

for either agricultural-related or forestry-related programs.

• In recent years, greater attention has been placed on 

specifically identifying agroforestry systems as meeting the 

criteria of Government programs to promote sustainable 

land use, especially for those programs related to ecosystem 

services and climate change mitigation.

• Future success in promoting the adoption and maintenance 

of agroforestry practices will require more focused policy 

initiatives that link specific agroforestry practices with 

anticipated benefits and funding opportunities.

• Agroforestry contributes to food security by integrating a 

diversity of edible species, especially fruit tees cultivated 

together with perennial food crops, and by providing fuel for 

cooking.

Key Information Needs

• Quantification and economic valuation of the ecosystem 

services provided by different agroforestry systems, 

especially as related to water resources, carbon storage and 

sequestration, biodiversity, and resilience to climate change 

and volatile national and global markets.

• Social, economic, and policy drivers that influence landuse change involving the establishment or conversion of 

agroforestry practices.

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130 Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions
Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions 131

Chapter 9

Challenges and Opportunities 

Toral Patel-Weynand, Gary Bentrup, Michele Schoeneberger, Tara Haan Karel, and PKR Nair 

Toral Patel-Weynand is the director of Sustainable Forest Management Research, U.S. Department of 

Agriculture (USDA), Forest Service, Research and Development; Gary Bentrup is a research landscape 

planner, USDA Forest Service, Research and Development, USDA National Agroforestry Center; Michele 

Schoeneberger is Research Program Lead and soil scientist (retired), USDA Forest Service, USDA National 

Agroforestry Center; Tara Haan Karel is an Oak Ridge Institute for Science and Education fellow, USDA 

Forest Service, State and Private Forestry; P.K. Ramachandran Nair is the Distinguished Professor of 

Agroforestry at the School of Forest Resources and Conservation, University of Florida.

This assessment focuses on the capacity of agroforestry as a 

management option to provide critical ecosystem goods and 

services to farms and ranches under changing conditions. Agroforestry provides farmers, ranchers, and even communities “with 

[tree-integrated] strategies to manage risk, whether it stems 

from uncertain markets or extreme weather patterns” (USDA 

2015). In addition to the benefits derived from current agroforestry use, several emerging opportunities may expand 

agroforestry’s contributions to supporting sustainable and 

resilient land management. These opportunities capitalize on 

agroforestry’s unique factors: its woody and long-lived nature; 

its ability to provide a variety of forest/tree-derived services of 

value to farmers, ranchers, and communities; and its versatility 

of design options.

Having been practiced throughout the world for centuries, 

agroforestry is not a new practice. Its use and research base, 

however, are relatively new within the context of modern 

U.S. agriculture. Research has verified the positive direction 

of agroforestry’s mitigative and adaptive services. Based on 

these findings, agroforestry practices are promoted by the U.S. 

Department of Agriculture (USDA) through the Farm Bill and 

are included in USDA Natural Resources Conservation Service’s 

conservation practice standards (USDA-NRCS [N.d.]). More 

research is required to meet customer demand for region-specific 

assistance and for the enhanced quantification of agroforestry’s 

impacts. To this end, USDA developed the Agroforestry Strategic Framework in 2011, which provides a general roadmap for 

the efficient advancement of agroforestry science and adoption 

in the United States (USDA 2011) (box 9.1).

Key findings and needs identified in this U.S. agroforestry 

assessment are presented in each chapter. Looking at all these 

findings and needs, two overarching conclusions become apparent: 

(1) increasing evidence shows how the forest-derived services 

generated by agroforestry can contribute to food security, 

rural economies, and the ecological health of U.S. agricultural 

landscapes, and (2) additional information, especially regarding 

the economics of these systems, will be needed to successfully 

capitalize on agroforestry’s benefits under changing conditions.

Box 9.1. USDA Agroforestry Strategic Framework, 2011 to 2016

Bringing together the ideas and resources of five U.S. 

Department of Agriculture (USDA) agencies, two key partners,

and a diverse group of stakeholders, the USDA Agroforestry 

Strategic Framework was developed to create a roadmap 

for advancing the science and application of agroforestry in 

the United States and U.S. territories (USDA 2011). It was 

built around three simple goals—adoption, science, and 

integration—with strategies listed for accomplishing these 

goals. These strategies were developed with the recognition 

that agroforestry could play a key role in enhancing America’s 

agricultural landscapes, watersheds, and rural communities. 

Addressing this diversity of issues from economic to 

biophysical, these strategies can help support the acceptance and adoption of agroforestry in the United States. 

Under the guidance of the Agroforestry Executive Steering 

Committee, a team of senior leaders from eight USDA 

agencies developed the report Agroforestry: USDA Reports 

to America, Fiscal Years 2011-12 (USDA 2015). Released in 

July 2015, this first ever report documented USDA-supported agroforestry efforts nationwide. An in-brief version of this 

document is available at: http://www.usda.gov/documents/

usda-reports-to-america-agroforestry-brief.pdf. 
132 Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions

In this chapter, the key information needs for realizing greater 

use and benefit from agroforestry are highlighted. Emerging 

opportunities for an expanded and more innovative use of agroforestry in resiliency strategies are then presented: agroforestry 

as a means to enhance urban food security, agroforestry as a 

means to produce sustainable bioenergy, and agroforestry as 

means to create more productive floodplains.

Information Challenges

To provide technical assistance that can encompass the 

many different combinations of species, arrangements, and 

management activities under agroforestry requires a greater 

understanding of the internal dynamics of these systems. For 

example, the ecophysiological dynamics of structure, function, 

and productivity are some of the parameters that play critical 

roles in maintaining sustainable agroforestry systems. The 

interactions between agroforestry plantings and the surrounding 

environment need to be more completely understood so we 

can better realize the potential benefits from expanding use. 

For agroforestry to be fully embraced within the United States, 

institutions, incentives, and motivations of landowners and 

other involved stakeholders need to be factored into the decisionmaking process. Key information challenges identified in this 

report have been grouped and will be discussed as follows—

• Productivity of Agroforestry Systems. 

• Impacts of Agroforestry Systems on Their Surroundings.

• Agroforestry Systems and Climate Change Mitigation. 

• Economic and Social Aspects of Agroforestry Systems. 

• Regional U.S. and North American (Canada and Mexico) 

Information Needs.

Productivity of Agroforestry Systems

To optimize productivity benefits from agroforestry, more 

information is needed to better tailor practices to the environment. Information and research needs include—

• Better understanding of how to capitalize on aboveground 

and belowground structure and processes that improve 

function performance, such as water and nutrient uptake.

• Better documentation of interactions in agroforestry 

practices over time, space, and planting options as they 

relate to production benefits and management strategies.

• Identification of tree and crop combinations and their 

management that can provide improved ecological services, 

including microclimate modification, pollination, and 

biological pest control in support of production.

• Design of innovative agroforestry-based food systems, especially

those suitable for marginal lands that can expand opportunities for food production and natural resource protection.

Impacts of Agroforestry Systems on Their 

Surroundings

To derive the fullest suite of ecosystem services from agroforestry, a better understanding of how these plantings interact 

biophysically and ecologically with surrounding environments 

is required. Information needs include—

• Identification of tree and crop species combinations and 

spatiotemporal configurations best suited for protecting and 

improving soil health.

• Better understanding of the impacts of agroforestry implementation on water resources, both quality and quantity, at 

the watershed scale.

• Improved placement and design of agroforestry practices 

that enhance water pollution and soil erosion control.

• Development of agroforestry practice designs that better 

incorporate biodiversity considerations, including corridor 

habitat for wildlife movement.

Agroforestry Systems and Climate Change 

Mitigation

To enhance the use of agroforestry for mitigating greenhouse 

gases (GHGs), information needs include—

• More comprehensive data for building the scientific basis 

of carbon (C) sequestration and GHG emission reduction, 

particularly nitrous oxide, by agroforestry systems.

• Development and validation of these GHG dynamics to 

account for agroforestry’s complex spatial and temporal 

interactions at entity to regional levels.

• Establishment of a common GHG assessment framework 

and set of protocols to advance measurement and predictive 

capacity of agroforestry’s GHG mitigation services across 

the United States.

Agroforestry can also be vulnerable to changing conditions, 

especially climatic variability. Information needs critical to 

understanding and managing these impacts include—

• Better prediction of agroforestry effects on crop and 

livestock yields under future climate scenarios.

• Refined models for predicting tree species suitability, 

adaptability, and growth under future climatic regimes.

• Plant evaluation trials and seed sourcing to develop better 

adapted plant materials for agroforestry in different regions 

of the United States.
Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions 133

Economic and Social Aspects of Agroforestry 

Systems

Current studies indicate that inclusion of agroforestry is not 

profitable when used on prime U.S. agricultural lands but is 

when used on marginal lands. Other studies suggest that the 

financial returns from use of agroforestry struggle to be competitive with annual agriculture. These studies, however, did 

not take into account the value of agroforestry’s other benefits 

beyond production. When incentives or payments for ecosystem 

services have been included, agroforestry can be competitive 

(Kulshreshtha and Kort 2009). Nonmarket valuation of these 

other services provide a more complete picture of agroforestry’s 

benefits and is particularly important in the formulation of 

policies and programs that encourage its use.

In addition to financial returns, other factors also determine the 

extent of agroforestry adoption, such as household preferences, 

resource endowments, market incentives, biophysical factors, 

and risk and uncertainty surrounding production. The role of 

risk and uncertainty appears to be more important for adopting 

agroforestry than for annual cropping innovations. Studies 

suggest that diversified systems like agroforestry may reduce 

whole-farm risk but more information is needed to better 

evaluate risk tradeoffs and uncertainty. Economic information 

needs include—

• Valuation of ecosystem services provided by agroforestry 

practices over multiple spatial scales and time.

• Better quantification of economic costs and benefits for 

producers implementing agroforestry practices.

• Understanding how agroforestry fits into production operations 

at different scales of production and marketing systems.

From a social science perspective, information needs include—

• Formulation of technical support and educational opportunities that are most effective at encouraging agroforestry 

adoption.

• Approaches that best apply that knowledge to the wide 

diversity of potential agroforestry adopters.

• Better understanding of landowners’ perceptions of climatic 

variability and change as it influences their adoption of 

agroforestry practices.

Regarding agroforestry in tribal and indigenous communities of 

the United States and U.S.-affiliated islands, information needs 

include—

• Better documentation of tribal and island agroforestry 

practices, with an emphasis on how these practices can 

improve food security and land management.

• Evaluations of the resiliency of tribal and island agroforestry 

systems to disturbances, including assessments of threats 

and opportunities to enhance sustainability.

• Broader understanding of the additional support tribes and 

island communities will require for adapting to current and 

anticipated climate-related impacts.

Regional U.S. and North American (Canadian 

and Mexican) Information Needs

Across the United States, a common information need is a 

better understanding of which agroforestry practices are best 

suited to the current climate, ecosystems, and agricultural 

operations within each region. In addition, we need to know 

which systems will be best adapted to expected climatic 

changes, particularly in regards to fluctuations in precipitation 

and temperature, pests, pollinators, and weeds. Gathering 

information on practices used by tribal and other indigenous 

groups can offer insight into specific regional agroforestry 

systems currently used that could be sustainably managed 

under evolving conditions. It is also critical to understand 

the associated economics, risks, and life-cycle costs and how 

these agroforestry systems can enhance the productivity and 

resilience of traditional agricultural and grazing systems.

The information gaps listed previously for U.S. regions apply 

to the Canadian provinces as well. Provincial support for 

agroforestry varies across Canada and will be a key factor in 

determining if agroforestry is to have an expanded role in supporting sustainable agriculture. Local conservation organizations exist in every Canadian province and can play an essential 

role in agroforestry adoption, especially if complemented 

by the creation of a national Canadian agroforestry network. 

Canada has an estimated 57 million hectares (approximately 

141 million acres) of degraded land that have limitations for 

conventional agricultural crop production. If only 5 percent 

of this degraded land area were converted to agroforestry, a 

potential annual C sink of 47 to 76 teragrams of carbon dioxide 

equivalent (up to 30 percent of the emission reductions for 

Canada) could be created (Van Rees 2008).

Although Mexican agroforestry systems are primarily tropical 

with more subsistence-based practices than in the United States 

and Canada, information needs in Mexico are similar but with 

some additional concerns. Agroforestry systems in Mexico are 

suffering major declines due to disease, climate change, low 

profits, and abandonment. These trends render agroforestry 

systems vulnerable to conversion to other, more intensified 

land uses. Land conversions currently are facilitated by a legal 

system that allows for the transition from one crop to another 

(such as shade-grown coffee to sugar cane plantations) without 

any consideration of tree-derived ecosystem services from the 

agroforestry system. Modification of national laws that would 
134 Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions

recognize and reward these multiple benefits by agroforestry 

systems is being pushed forward. Proposed legal reforms 

would make land under agroforestry production a hybrid land 

use eligible for participation in national agriculture and forestry 

programs.

Emerging Opportunities: Capitalizing on 

Agroforestry’s Versatility

The versatility and flexibility of agroforestry design afford 

us many opportunities for addressing new and emerging 

challenges. Three promising and innovative applications for 

agroforestry use in the United States are (1) bioenergy production, (2) urban food security, and (3) productive floodplain 

management.

Bioenergy Production

Demands on U.S. agricultural lands continue to grow for food, 

feed, and fiber and for other ecosystem services such as flood 

control, water quality protection, GHG mitigation, and wildlife 

habitat. With the additional demand to produce bioenergy 

from these lands, the sustainability and health of U.S. agricultural lands will be determined by the way in which bioenergy 

production and these other demands are handled, especially 

under conditions created by escalating extreme weather events 

(Gopalakrishnan et al. 2009).

Agroforestry systems can potentially augment biofeedstock 

production for bioenergy use, offering several advantages, 

especially when services for adapting to shifting weather and 

climate are considered. These advantages include (1) providing 

an environment-friendly production option for marginal lands, 

(2) reducing risk through diversification of income and biofeedstock sources attained by combining herbaceous and woody 

species into agroforestry systems, and (3) provisioning ecosystem 

services (i.e., protection of soil, water and air quality, and biodiversity) critical to enhancing adaptive capacity under shifting 

climate (Holzmueller and Jose 2012, Jose and Bardhan 2012, 

Thevathasan et al. 2014). Riparian forest buffers, windbreaks, 

and alley cropping appear to be the most promising for maximizing biomass production for bioenergy without sacrificing 

food production (Cardinael et al. 2012, Fortier et al. 2010, 

Gamble et al. 2014, Holzmueller and Jose 2012, Tsonkova 

et al. 2012). In the case of riparian forest buffers, harvesting 

biofeedstock in the zones closest to the adjacent land use can 

restore the nutrient uptake capacity of the plant materials, 

maintaining water quality functions of the system (Schultz et 

al. 2009) (fig. 9.1).

Urban Food Security

More than 80 percent of the U.S. population resides in metropolitan areas. These urbanized regions face many challenges, 

some of which agroforestry can help address. Increasing 

efforts are being made to grow food within cities as a means 

for diversifying production sources and enhancing food 

security under a dynamic climate (FAO 2011). One strategy 

for addressing this challenge is urban food forestry or food 

forests, which is simply the agroforestry practice of forest 

farming applied in an urban environment to produce food and 

other ecosystem services, including air-quality enhancement, 

Figure 9.1. A conceptual illustration of a riparian forest buffer producing biofeedstock for bioenergy while offering services, including water-quality protection, greenhouse gas mitigation, climate change adaptation, and other ecosystem services. (From Schoeneberger et al. 2012).
Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions 135

stormwater management, and biodiversity habitat (Clark and 

Nicholas 2013). Urban food forestry relies on perennial woody 

vegetation to provide fruits and nuts while also supporting the 

production of other food crops (Krishnan et al. 2016, McLain 

et al. 2012). Targeting food forests at metropolitan locations 

vulnerable to flooding or urban heat island effects can help 

optimize the returns under climatic variability (Gill et al. 2007). 

Numerous urban food forestry projects are being planted in 

communities around the United States and offer an opportunity 

to use agroforestry science and technology to grow edible 

products while delivering other important ecosystem services 

in an urban environment (http://communityfoodforests.com/) 

(fig. 9.2).

Productive Floodplain Management

Many of the natural woody ecosystems once present in 

floodplains have been highly altered or removed to create 

productive farmland. With these alterations came extensive 

flood-control efforts to compensate for the loss of natural 

floodplains and to protect communities, roads, and agricultural 

fields. Even with the best available flood-control techniques, 

however, rivers still flood often with devastating consequences. 

With expected increases in flooding under climate change, a 

need exists for creating floodplain systems that accommodate, 

rather than control, flooding and that still maintain economic 

and biological attributes. One option for creating productive 

floodplains is through the establishment of carefully planned 

and managed waterbreaks (Wallace et al. 2000).

Waterbreaks offer a novel agroforestry system for reducing 

impacts from flood events by providing a series of strategically 

placed buffers in the floodplain (fig. 9.3). A waterbreak is a 

planned floodplain system of linear woody buffers oriented to 

reduce flooding impacts and to provide supplemental benefits 

(Wallace et al. 2000). The placement and use of waterbreaks 

are intended to moderate water velocity similar to the way 

windbreaks moderate wind velocity. Crops in floodplains have 

a roughness coefficient of 0.025–0.045 Manning’s N, and 

woody vegetation can increase the coefficient to 0.08–0.16, 

which can reduce flood velocities by around 70 percent 

(Chow 1959, Fathi-Moghadam and Drikvandi 2012). Flood 

damage evaluation and onsite observation from the Great 

Midwest Flood of 1993 (a 500-year flood event) showed 

that fields protected with tree corridors experienced 25 to 75 

percent lower reclamation costs (Wallace et al. 2000). During 

nonflooded conditions, waterbreaks can provide critical wildlife 

corridors between upland and riparian areas and improve water 

quality by trapping sediment and filtering chemicals from 

runoff. These features can also provide alternative income for 

landowners through hunting fees and harvesting products, such 

as timber, nuts, and other nontimber forest products.

Figure 9.2. The Dr. George Washington Carver Edible Park in Asheville, NC, is one of the oldest food forests established in 

the United States. Planted in 1997 on a former landfill, figs, apples, pears, chestnuts, hazelnuts, plums, peaches, grapes, and 

pawpaws are just some of the food producing trees that are available to the public for consumption. (Photos courtesy of Catherine 

Bukowski, Virginia Tech). 
136 Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions

Figure 9.3. A conceptual illustration of a waterbreak producing flood management services and offering other ecosystem services. 

(From Schoeneberger et al. 2012).

Conclusions

Agriculture in the United States is facing the daunting task 

of meeting ever-increasing production and environmental 

demands on a finite land base—all under the increasing uncertainty of weather and projected climate (Walthall et al. 2012). 

Practices are needed that can bolster the health and resiliency 

of U.S. agricultural landscapes today while helping producers 

proactively “hedge their bets” for the future. Agroforestry, a 

unique tree-based management activity for agricultural lands, 

is one such practice that offers the advantage of providing 

integrated mitigative and adaptive services while producing 

other ecosystem services of value to producers and society. As 

such, agroforestry can be a “no/low-regrets” option, providing 

near-term benefits while then being in place to address future 

weather and climate impacts if and when they occur.

Effective adaptation to climatic variability and change 

requires timely information and actionable science to assist 

in decisionmaking. Agroforestry, which did not begin as a 

science in the United States until recently (Jose et al. 2012), 

is lacking the robust science base traditional agricultural and 

forestry practices have. This assessment identified key needs 

for timely and actionable knowledge on the use of agroforestry 

as a climate-smart practice. With contributions from many 

experts and drawing from the rapidly growing database for 

agroforestry, this assessment provides the first-ever synthesis 

regarding agroforestry’s potential to reduce threats and build 

resilient agricultural landscapes in the United States. The report 

identifies key findings and research needs vital to optimizing 

these services by currently used agroforestry practices. 

Perhaps, more importantly, it points out the potential for a more 

innovative and expanded use of agroforestry as a management 

option for addressing the multiple challenges that our Nation’s 

lands face.

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138 Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions
Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions 139

Glossary

adaptation—Adjustment in a natural or human system 

in response to actual or expected climatic stimuli or their 

effects that moderates harm or exploits beneficial opportunities.

adaptive capacity—The ability of a system to adjust to 

climate change (including climate variability and extremes), 

to moderate potential damages, to take advantage of 

opportunities, or to cope with the consequences.

adaptive management—A decision process that 

promotes flexible decisionmaking that can be adjusted in 

the face of uncertainties as outcomes from management 

actions and other events become better understood. Careful monitoring of these outcomes both advances scientific 

understanding and helps adjust policies or operations as 

part of an iterative learning process.

afforestation—Direct human-induced conversion of land 

that historically has not been forested to forested land 

through planting, seeding, and/or the human-induced 

promotion of natural seed sources. Most agroforestry 

plantings in temperate regions do not meet the definition of 

forest based on size criteria. As such, they do not qualify 

as afforestation practices, although ecologically they are 

afforestation like in their growth and ecological behavior.

agrodeforestation—The process of destroying or 

neglecting the traditional agroforestry systems in favor of 

plantation-type agriculture.

agroforestry—Intensive land-use management that 

optimizes the benefits (physical, biological, ecological, 

economic, and social) from biophysical interactions created 

when trees and/or shrubs are deliberately combined with 

crops and/or livestock.

agroforestry practice—A category of agroforestry based 

on the type and purpose of the planting. The five categories 

of agroforestry practices recognized in the United States 

and Canada include windbreaks, riparian forest buffers, 

alley cropping, forest farming, and silvopasture, with a 

growing sixth category to capture modifications of the 

five practices for use in addressing emerging issues (e.g., 

stormwater treatment, biofeedstock production). See also 

box 1.1 in chapter 1.

agroforestry system—A land-use management system 

in which woody perennials (trees, shrubs, bamboos, palm 

trees, woody lianas) are grown on the same land management unit with crops and/or livestock to create interactions 

considered beneficial to the producer and/or the land. An 

agroforestry system can be subdivided into other systems 

and is a part of larger systems. See also box 1.1 in chapter 1.

alley cropping—The planting of trees or shrubs in two 

or more sets of single or multiple rows with agronomic, horticultural, or forage crops cultivated in the alleys between 

the rows of woody plants.

beneficial insect—Any of a number of species of insects 

that perform valued services like pollination and pest control.

biodiversity—The variability among living organisms from 

all sources, including within species, among species, and 

of ecosystems.

bioenergy—Any renewable energy made from biological 

sources. Fossil fuels are not counted because, even though 

they were once biological, they are long dead and have 

undergone extensive modification.

biofeedstock—Any renewable, biological material that can 

be used directly as a fuel or be converted to another form 

of fuel or energy product.

biofuel—Any liquid, gaseous, or solid fuel produced from 

biofeedstock.

biological corridor—Geographic track that allows for the 

exchange and migration of species within one or more ecosystems. Its function is to maintain connectivity of biological 

processes to avoid the isolation of species populations.

biological pest control—The beneficial action of predators, parasites, pathogens, and competitors in controlling 

pests and their damage. Biological control provided by these 

living organisms (“natural enemies”) is especially important 

for reducing the number of pest insects and mites.

biomass—The total mass of living organisms in a given area or volume; recently dead plant material is often included 

as dead biomass. The quantity of biomass is expressed as 

a dry weight or as the energy, carbon, or nitrogen content.
140 Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions

carbon allocation—The distribution of carbon within the 

various components of an entity of concern (i.e., from a 

single tree to the whole ecosystem of which that tree may 

be part). In the case of this report, carbon allocation refers 

to the apportionment or distribution of carbon in the various 

components of the plants and soil system.

carbon dioxide (CO2

)—A naturally occurring gas, fixed by 

photosynthesis into organic matter and also a byproduct 

of burning fossil fuels and biomass, land-use changes, and 

other industrial processes. It is the principal anthropogenic 

greenhouse gas that affects the Earth’s radiative balance. 

It is the reference gas against which other greenhouse 

gases are measured and, therefore, has a global warming 

potential, or GWP, of 1.

carbon equivalent—A quantity that describes, for a given 

mixture of greenhouse gas (GHG), the amount of carbon 

dioxide (CO2) that would have the same global warming 

potential (GWP) when measured over a specified timescale 

(in general, 100 years). The GWPs of the three GHGs 

associated with forestry are as follows: (1) CO2 persists in 

the atmosphere for about 200 to 450 years and its GWP 

is defined as 1, (2) methane persists for 9 to 15 years 

and has a GWP of 25 (meaning that is has 25 times the 

warming ability of carbon dioxide), and (3) nitrous oxide 

persists for about 120 years and has a GWP of 310.

carbon flux—The rate at which carbon moves to or from 

a particular component of an ecosystem per unit ground 

area per unit time.

carbon footprint—The total amount of greenhouse gases 

that are emitted into the atmosphere each year by a person, 

family, building, organization, or company.

carbon sequestration—The processes that remove 

carbon dioxide (CO2) from the atmosphere. Terrestrial or 

biological carbon sequestration is the process by which 

plants absorb CO2

, release the oxygen, and store the 

carbon. Geologic sequestration is one step in the process 

of carbon capture and sequestration and involves injecting 

CO2 deep underground where it stays permanently.

carbon sink—Any process, activity, or mechanism that 

removes carbon dioxide from the atmosphere. Carbon 

sinks include the oceans, plants, and other organisms that 

remove carbon from the atmosphere via photosynthetic 

processes.

carbon stock—The quantity of carbon held within a pool 

at a specified time.

chilling requirement—The minimum period of cold 

weather after which a fruit- or nut-bearing tree will break 

dormancy and begin flowering.

climate—In a narrow sense, the average weather or, more 

rigorously, the statistical description in terms of the mean 

and variability of relevant quantities over a period of time 

ranging from months to thousands or millions of years. 

The classical period is 30 years, as defined by the World 

Meteorological Organization. The relevant quantities are 

most often surface variables such as temperature, precipitation, and wind. In a wider sense, the state, including a 

statistical description, of the climate system.

climate change—A statistically significant variation in 

either the mean state of the climate or in its variability, persisting for an extended period (typically decades or longer). 

Climate change may be due to natural internal processes 

or external forcings, or it may be due to persistent anthropogenic changes in the composition of the atmosphere 

or in land use. Note that Article 1 of the United Nations 

Framework Convention on Climate Change (UNFCCC), 

defines climate change as “...a change of climate which is 

attributed directly or indirectly to human activity that alters 

the composition of the global atmosphere and which is in 

addition to natural climate variability observed over comparable time periods.” The UNFCCC thus makes a distinction 

between climate change attributable to human activities 

altering the atmospheric composition and climate variability

attributable to natural causes. See also climate variability.

climate change adaptation—The efforts by society or 

ecosystems to prepare for or adjust to the changes in climate.

climate change mitigation—Human intervention to 

reduce the human impact on the climate system, including 

strategies to reduce greenhouse gas (GHG) sources and 

emissions and to enhance GHG sinks. See also mitigation.

climate smart agriculture—An approach to developing 

the technical, policy, and investment conditions to achieve 

sustainable agricultural development for food security 

under climate change.

climate variability—Variations in the mean state and other statistics (such as standard deviations, the occurrence of 

extremes) of the climate on all temporal and spatial scales 

beyond that of individual weather events. Variability may be 

due to natural internal processes within the climate system 

(internal variability) or to variations in natural or anthropogenic 

external forcing (external variability). See also climate change.
Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions 141

cultivar—A contraction of “cultivated variety,” referring to 

a plant type within a particular cultivated species that is 

distinguished by one or more characters.

ecosystem service—An ecological process or function 

having monetary or nonmonetary value to individuals or 

society at large. Ecosystems services are (1) supporting 

services, such as productivity or biodiversity maintenance; 

(2) provisioning services, such as food, fiber, or fish; (3) 

regulating services, such as climate regulation or carbon 

sequestration; and (4) cultural services, such as tourism or 

spiritual and aesthetic appreciation.

enterprise budget—A financial management tool to 

estimate the costs and receipts (income) associated with 

the production of a specific agricultural product.

evapotranspiration—The sum of evaporation and plant 

transpiration. Evaporation accounts for the movement 

of water to the air from sources such as the soil, canopy 

interception, and water bodies. Transpiration accounts for 

the movement of water within a plant and the subsequent 

loss of water as vapor through stomata in its leaves.

First Nations—The aboriginal groups formally recognized 

by the Canadian Government under the Federal Indian Act 

of 1876.

food security—A situation that exists when people have 

secure access to sufficient amounts of safe and nutritious 

food for normal growth, development, and an active and 

healthy life. Food insecurity may be caused by the unavailability of food, insufficient purchasing power, inappropriate 

distribution, or inadequate use of food at the household level.

forest farming—The intentional cultivation of edible, 

medicinal, or decorative specialty crops beneath native 

or planted woodlands that are managed for both wood 

and understory crop production. Forest farming does not 

include the gathering of naturally occurring plants from 

native forests, also known as wildcrafting.

greenhouse gas (GHG)—Any gas whose absorption of 

solar radiation is responsible for the greenhouse (warming) 

effect. Some GHGs, such as carbon dioxide (CO2

), may be 

emitted or drawn from the atmosphere through natural processes or human activities. Other GHGs, such as certain 

fluorinated gaseous compounds, are created and emitted 

solely through human activities. The principal GHGs that 

enter the atmosphere because of human activities are 

CO2

, water vapor, methane, and nitrogen oxide and also 

fluorinated gases, such as hydrofluorocarbons, perfluorocarbons, and sulfur hexafluoride.

greenhouse gas mitigation—A human intervention to 

reduce the human impact on the climate system, including 

strategies to reduce greenhouse gas (GHG) sources and 

emissions and to enhance GHG sinks.

greenhouse gas sink—Any process, activity, or mechanism that removes a greenhouse gas (GHG), an aerosol, or 

a precursor of a GHG or aerosol from the atmosphere.

greenhouse gas source—Any process activity or mechanism that releases a greenhouse gas (GHG), an aerosol, or 

a precursor of a GHG or aerosol into the atmosphere.

homegarden—A private-property garden around a house that 

contains various trees, crops, and animals. Homegardens 

exist more in tropical areas than in cooler climates.

intercropping system—The growing of two or more 

different species of crops simultaneously, as in alternate 

rows in the same field or single tract of land.

living fence—Rows of living plants, such as grasses, 

shrubs, and trees, that are strategically planted to work as 

a structural barrier.

methane emission—The production and discharge of 

methane (CH4

) that occur by natural sources such as 

wetlands and also by human activities such as leakage 

from natural gas systems and the raising of livestock. 

Agricultural emissions of CH4 are caused when domestic 

livestock such as cattle, buffalo, sheep, goats, and camels 

produce large amounts of CH4 as part of their normal 

digestive process.

microclimate—The local climate of a given site or habitat 

varying in size from a tiny crevice to a large land area, but 

being usually characterized by considerable uniformity of 

climate over the site involved and relatively local compared 

with its enveloping macroclimate from which it differs 

because of local climatic factors (such as elevation and 

exposure).

multifunctional agriculture—The practice of farming that 

produces various noncommodity outputs in addition to food.

nitrous oxide emission—The production and discharge 

of nitrous oxide (N2

O) that occur naturally through many 

sources associated with the nitrogen cycle, which is the 

natural circulation of nitrogen among the atmosphere, 

plants, animals, and microorganisms that live in soil and 

water. Agricultural emissions of N2O are caused when people 

add nitrogen to the soil through the use of synthetic fertilizers.

nonpoint source pollution—Introduced contaminants 

whose source is general rather than specific in location.
142 Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions

nontimber forest products—Goods harvested from 

woodlands, including herbal plants like ginseng and 

goldenseal, specialty mushrooms like shiitake and reishi, 

and wild foods.

particulate matter—Very small pieces of solid or liquid 

matter, such as particles of soot, dust, fumes, mists, or 

aerosols. The physical characteristics of particles and how 

they combine with other particles are part of the feedback 

mechanisms of the atmosphere.

phenology—The study of natural phenomena that recur 

periodically (e.g., developmental stages, migration) and 

their relation to climate and seasonal changes.

resiliency—The ability of a social or ecological system 

to absorb disturbances while retaining the same basic 

structure and ways of functioning, the capacity for self-organization, and the capacity to adapt to stress and change.

riparian forest buffers—An area of trees, shrubs, and 

herbaceous vegetation established and/or managed 

adjacent to streams, lakes, ponds, and wetlands.

shelterbelt—A single row or multiple rows of trees and 

possibly shrubs planted in a linear fashion and established 

upwind of the areas to be protected. Although this term is 

more often used interchangeably with windbreaks, some 

use this term to designate thicker (i.e., more plant rows) 

plantings to provide protection to farmsteads and livestock.

silvopasture—The intentional combination of trees, forage 

plants, and livestock in an integrated, intensively managed 

system.

soil organic carbon—The carbon occurring in the soil in 

soil organic matter, a term used to describe the organic 

constituents in the soil (tissue from dead plants and 

animals, products produced as these decompose, and the 

soil microbial biomass).

subsurface tile drain—A conduit installed beneath 

the ground surface to collect and/or convey subsurface 

drainage water.

taungya—A Burmese word that is now widely used to describe the agroforestry practice, in many tropical countries, 

of establishing tree plantations by planting and tending 

tree seedlings together with food crops. Food cropping is 

ended after 1 to 2 years as the trees grow.

uncertainty—An expression of the degree to which 

a value (e.g., the future state of the climate system) is 

unknown.

vulnerability—The degree to which a system is susceptible to, or unable to cope with, adverse effects of 

climate and global change, including climate variability and 

extremes.

weather—The specific condition of the atmosphere at a 

particular place and time. Weather is measured in terms of 

parameters such as wind, temperature, humidity, atmospheric pressure, cloudiness, and precipitation.

windbreak—A single row or multiple rows of trees or 

shrubs that are established for environmental purposes.
Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions 143

Appendix A

Regional Summaries

Alaska

Linda E. Kruger

Linda E. Kruger is a research social scientist, U.S. Department of Agriculture, Forest Service, Pacific 

Northwest Research Station, Juneau Forestry Sciences Laboratory.

Description of the Region

Alaska is a vast State covering 586,412 square miles, an area 

roughly one-fifth the size of the contiguous United States. It is 

the northernmost, easternmost, and westernmost State. Alaska 

has 318 different soil types and 100 volcanoes, more than 40 of 

which have been active in historic time, making up 80 percent 

of the active volcanoes in the United States.

Permafrost is thickest in the arctic, north of the Brooks Range, 

but it can be found in nearly 85 percent of the State. Glaciers, 

ice fields, high alpine tundra, moist coastlines, fjords, and rainforests limit the potential for agroforestry in much of Alaska. 

Forests cover approximately one-third of the total land area 

of Alaska (Parson et al. 2001), with 72 percent of the forest 

cover being in public ownership (Oswalt et al. 2014). The 

Federal Government is the largest owner of forest land: more 

than 10 million acres (ac) are within the boundaries of two 

national forests managed by the U.S. Department of Agriculture 

(USDA) Forest Service; 17 million ac are managed by the U.S. 

Department of the Interior, Bureau of Land Management; and 

36 million ac are managed by other Federal agencies.

The State of Alaska manages 28 million ac of forest land 

(Oswalt et al. 2014). Only about 36 million ac of forest land 

are privately owned by individuals and another 33 million ac 

are owned by private corporations (Oswalt et al. 2014). Of the 

total forest acreage, 90 percent is interior boreal forest and the 

other 10 percent is in coastal temperate rainforest (Wolken and 

Hollingsworth 2012). Arable land suitable for crop production 

is extremely limited in Alaska; only 0.2 percent of the land 

is currently being actively farmed (USDA NASS 2014). For 

these reasons, the level of commercial forestry and commercial 

agriculture operations in Alaska is small when compared with 

many other States.

Alaska Natives have resided in the State “since time immemorial,” determined to be more than 10,000 years. Today, 

many Alaska Natives continue to participate in traditional 

hunting, fishing, and gathering activities. Nonnative residents 

also have adopted the harvest and use of plants, animals, and 

fish as part of a natural resource-based lifestyle referred to 

in Alaska as subsistence (Berman et al. 1998). The gathering 

and harvesting of forest products provide an opportunity to 

perpetuate traditional ways; engage in recreational, social, and 

family activities; find spiritual connection; and acquire food 

and material goods to support a livelihood.

Three primary factors influence Alaska’s climate. First, Alaska’s 

high latitude, ranging from 51°N. to 71°N., results in extreme 

variations in solar radiation. Second, with 33,904 miles of 

tidal shoreline—more coastline than the contiguous United 

States—a significant portion of the State is influenced by ocean 

currents and, in the far north, by sea ice. Coastal locations are 

characterized by relatively small seasonal temperature variability and high humidity. Inland locations, not directly influenced 

by oceans, experience a climate more characterized by large 

daily and annual temperature fluctuations, low humidity, and 

relatively light and irregular precipitation (Alaska Climate 

Research Center 2014). The third factor, the elevation, which 

ranges from sea level to 20,320 feet above sea level, also 

influences the State’s climate.

Glaciers cover approximately 5 percent of the State (29,000 

square miles). Both commercial agriculture and commercial 

forestry are very limited compared with the same activities in 

many other States. As mentioned previously, forests cover only 

one-third of the land base (USDA NASS 2014).

Most farms in Alaska are in the Matanuska Valley northeast of 

Anchorage and the Tanana Valley east of Fairbanks. In 2014, 

760 farms were operating on 830,000 ac (USDA NASS 2014). 

The top agricultural revenue producers are greenhouse and 

nursery products, with barley, hay, oats, and potatoes being 

the prevalent field crops. Having the benefit of long hours of 

summer sunlight, the Matanuska Valley produces world-record 

crops, such as a 19-pound carrot, a 76-pound rutabaga, and a 

127-pound cabbage.
144 Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions

Agroforestry in Alaska

Very little agriculture is mixed with forestry at this time in Alaska. 

During fiscal years 2010 through 2014, only 20 completed or 

planned agroforestry activities were documented: 4 windbreaks/

shelterbelts; 4 multistory croppings (forest farming); 8 riparian 

forest buffers; and 4 silvopastures (Western Forestry Leadership 

Coalition 2012). Several nontimber specialty crops are produced 

in Alaska that, depending on the level of management, could be 

considered forms of agroforestry. Brief discussions on each of 

these activities are included below.

Silvopasture

Grazing of understory vegetation in young forests and woodlands 

is not well documented. Although such grazing may occur on 

a limited basis in interior Alaska, no documentation of this 

activity was found, beyond the notation from the Western 

Forestry Leadership Coalition.

Riparian Forest Buffers

Riparian buffers are an increasing component of forest 

restoration efforts in southeast Alaska and may help offset 

some climate change impacts on aquatic health and fisheries. 

Riparian buffer standards are published in Alaska Department 

of Natural Resources (2007), but Alaska has not adopted the 

USDA Natural Resources Conservation Service (NRCS) 

Conservation Practice Standards on Riparian Forest Buffer, 

Windbreak/Shelterbelt Establishment, and Windbreak/Shelterbelt Renovation (Graham 2015).

Forest Farming

Many opportunities exist in Alaska for growing potentially highvalue understory crops, including mushrooms, berries (Holloway 2006), medicinal plants, and plants used for tea and other 

products. DENALI BioTechnologies, Inc. (http://denalibiotech.

com), located in Homer in southern Alaska, produces nutraceuticals—dietary supplements with health benefits. One product is 

made from wild blueberries and huckleberries harvested from 

around the State. Dandelions and rosehips are also harvested 

for other products. Many of the berries come from Kake in 

southeast Alaska, where Sealaska Corporation owns and manages 20,000 ac of forest land. Sealaska obtained USDA organic 

certification for its young growth forests and, subsequently, 

blueberry prices topped $3.10 per pound (Savell 2012).

At Starrigavan Creek Watershed in Sitka, also in southeast 

Alaska, the growth of wild berries is being encouraged through 

thinning and habitat improvement efforts (USDA NRCS 2014). 

Other plants are also harvested in the wild (see the Specialty 

Products section). An expansion of forest farming could provide 

an opportunity to increase the harvest and reliability of various 

crops while assuring the sustainability of the plants.

Alley Cropping

Four Alaska farms reported that they practiced alley cropping 

or silvopasture in 2012 (MacFarland 2014). The potential may 

exist for expansion in some locations.

Specialty Products

Spruce tips are harvested in Gustavus, in southeast Alaska, for 

use in a specialty beer produced in Juneau. Spruce tips are also 

used in jams and jellies.

Birch syrup is commercially produced in the interior of Alaska, 

with more than 1,500 gallons of syrup produced in 2013. In 

addition to producing spruce syrup, a wild medicinal Alaska tea 

made from Chaga mushrooms (Inonotus obliquus) that grow 

primarily on live birch trees in cold climates is also marketed.

Several studies have explored the feasibility of wood energy, 

including pellets and bricks, for residential heating (Nicholls et 

al. 2010). Wood-fired heating systems currently are being used 

in Juneau, Craig, and other communities and a pellet plant in 

Fairbanks produces wood pellets.

Threats and Challenges to Agricultural 

Production and Community Well-Being

Food insecurity is a significant and growing problem in Alaska, 

resulting from limitations in land suitable for food production, 

decreasing sources and harvests of traditional foods, and a 

heavy reliance on imported foods. Alaska is already a region 

that has experienced significant warming during the past 60 

years, which has led to earlier spring snowmelt, warmer permafrost, widespread droughts, and extensive insect outbreaks 

and wildfire (Melillo et al. 2014). These effects are reducing 

the growth and availability of many of the traditional foods that 

historically have been heavily relied on. Impact on permafrost 

is expected to negatively affect transportation capabilities, 

further exacerbating food security issues. These impacts are 

expected to persist and worsen under climate change, with 

Native Alaska communities being especially vulnerable.

Developing Agroforestry Opportunities

Wild Alaska berries have long been important to Alaska 

Native people. The recognized and now documented health 

benefits of Alaskan berry resources are positive incentives for 

development of commercial production (Kellogg et al. 2011). 

Several opportunities exist for commercialization of berry 

harvest and production. A few small-scale operations around 

the State harvest berries and produce and sell jams, jellies, 

syrups, and other berry products (see the previous Specialty 

Products section). Expansion of a commercial berry industry 

would require striking “a strategic balance between the tribes 
Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions 145

and the marketplace, extraction and preservation of resources, 

traditional activities and modern business practices and more 

investigation into the interplay of these factors” (Kellogg et 

al. 2011). It appears this balance has been effectively achieved 

with wild berry harvests in Kake.

The University of Alaska Fairbanks has developed agroforestry 

and demonstration projects at its Matanuska Experiment Farm 

and Delta Junction field research site to identify plants (e.g., 

berries, fruit trees, medicinal plants) with agroforestry potential 

(Western Forestry Leadership Coalition 2012). The NRCS 

has published a fairly comprehensive guide for managing wild 

berry stands (Holloway 2006).

The predicted warming of the subarctic and arctic areas in 

Alaska may afford opportunities to produce food crops locally. 

Work by Barbeau et al. (2015) in the subarctic region of 

Canada demonstrated that crops such as potato and bush bean 

could be grown and that their yield could be increased through 

the use of willow windbreaks. Willow is a common and diverse 

species in Alaska, which suggests resilient agroforestry systems 

for vegetable crop production and for other products from the 

willow (e.g., feedstock for heat or combined heat/power generation) 

can be a viable component in Alaska climate-smart strategies.

The State of Alaska is expanding green firebreaks near the 

community of Tok in east-central Alaska to help protect the 

community from wildfire, while providing a source of wood for 

bioenergy. According to Jeff Hermanns, the Tok Area Forester, 

a wood-chip boiler system heats the Tok School and a greenhouse, and it generates power. The project supplies 2,000 tons 

of wood energy per year, saving the community $80,000 to 

$100,000 per year (Hermanns 2015). The project was described 

in the TimberWest journal (TimberWest Publications 2012). 

In addition, more than 20 wood-energy systems are operating 

in Alaska. The Renewable Energy Alaska Project documents 

several wood-energy projects on its biomass Web page (http://

alaskarenewableenergy.org/why-renewable-energy-is-important/alaskas-renewable-energy-projects/). The Alaska Energy 

Authority also tracks wood-energy projects and administers a 

renewable-energy fund (http://akenergyauthority.org/AEEE/

Biomass/AWEDTG).

Key Information Needs

• Additional research is needed to help determine how agroforestry systems can be designed for use in Alaska to support 

the sustainable production of edible native foods and other 

crops and woody biomass for energy and also to maximize 

wildlife and fish habitat and provide other benefits.

• Locally adapted and diverse plant materials, both woody and 

herbaceous, need to be developed to build more climate-adapted 

agroforestry practices suited to Alaska’s environment.

Literature Cited

Alaska Climate Research Center. 2014. There are three 

primary factors that contribute to Alaska’s climate. http://

akclimate.org/Climate. (18 October 2016).

Alaska Department of Natural Resources. 2007. Alaska 

forest resources & practices regulations. http://forestry.

alaska.gov/Assets/uploads/DNRPublic/forestry/pdfs/

reforestation/07JuneForestResourcesPracticesActRegulations.

pdf. (18 October 2016).

Barbeau, C.D.; Oelbermann, M.; Karagatzides, J.D. [et al.]. 

2015. Sustainable agriculture and climate change: producing 

potatoes (Solanum tuberosum L.) and bush beans (Phaseolus 

vulgaris L.) for improved food security and resilience in a 

Canadian subarctic First Nations community. Sustainability. 

7(5): 5664–5681.

Berman, M.; Juday, G.; Burnside, R. 1998. Climate change 

and Alaska’s forests: people, problems, and policies. 

http://www.besis.uaf.edu/besis-oct98-report/Forestry.pdf. 

(15 November 2016).

Graham, J. 2015. Personal communication. Forest Stewardship Program Coordinator. Alaska Division of Forestry, 550 

West 7th Avenue, Suite 1450, Anchorage, AK 99501.

Hermanns, J. 2015. Personal communication. Tok Area 

Forester, Alaska Division of Forestry, Area Box 10, Tok, Alaska 

99780.

Holloway, P.S. 2006. Managing wild bog blueberry, lingonberry, cloudberry, and crowberry stands in Alaska. Report for 

University of Alaska Fairbanks and Natural Resource Conservation Service, Fairbanks. 12 p.

Kellogg, J.; Higgs, C.; Lila, M.A. 2011. Prospects for commercialization of an Alaska Native wild resource as a commodity 

crop. Journal of Entrepreneurship. 20(1): 77–101.

MacFarland, K. 2014. Agroforestry: programs, policies, and 

trends. Presentation at the Agroforestry Workshop held by 

Oregon State University, Corvallis, OR. 21–22 October 2014. 

http://www.forestry.oregonstate.edu/sites/www.forestry.

oregonstate.edu/files/agroforestry/AgroforestryUSDA.pdf. 

(18 October 2016).

Melillo, J.M.; Richmond, T.C.; Yohe, G.W., eds. 2014. Climate 

change impacts in the United States: the third national climate 

assessment. Washington, DC: U.S. Global Change Research 

Program. 841 p. http://nca2014.globalchange.gov. (30 October 

2014).

Nicholls, D.L.; Brackley, A.M.; Barber, V. 2010. Wood energy 

for residential heating in Alaska: current conditions, attitudes, 

and expected use. Gen. Tech. Rep. PNW-GTR-826. Portland, 

OR: U.S. Department of Agriculture, Forest Service, Pacific 

Northwest Research Station. 30 p.

Oswalt, S.N.; Smith, W.B.; Miles, P.D.; Pugh, S.A. 2014. Forest 

resources of the United States, 2012: a technical document 

supporting the Forest Service 2015 update of the RPA assessment. Gen. Tech. Rep. WO-91. Washington, DC: U.S. Department of Agriculture, Forest Service, Washington Office. 218 p.
146 Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions

Parson, E.A.; Carter, L.; Anderson, P. [et al.]. 2001. Potential 

consequences of climate variability and change for Alaska. In: 

National Assessment Synthesis Team, eds. Climate change 

impacts on the United States: foundation report. Cambridge, 

United Kingdom: Cambridge University Press: 283–312.

Savell, S. 2012. Kake forests provide more than just trees. 

http://blogs.usda.gov/2012/12/05/kake-forests-provide-morethan-just-trees/. (18 October 2016).

TimberWest Publications. 2012. Heating up. TimberWest: 

Journal of Logging and Sawmills. May/June. http://forestnet.

com/TWissues/may_june2012/heating_up.php. (18 October 

2016).

U.S. Department of Agriculture, National Agricultural Statistics 

Service (USDA NASS). 2014. 2012 census volume 1, chapter 

2: state level data. Washington, DC: U.S. Department of 

Agriculture, National Agricultural Statistics Service. http://

www.agcensus.usda.gov/Publications/2012/Full_Report/

Volume_1,_Chapter_2_US_State_Level/. (18 October 2016).

U.S. Department of Agriculture, Natural Resources Conservation Service (USDA NRCS). 2014. NRSC forestry projects in 

southeast Alaska. http://www.ak.nrcs.usda.gov/wps/portal/

rrcs/main/ak/newwsroom/factsheeets/. (17 November 2016).

Western Forestry Leadership Coalition. 2012. Western 

agroforestry case studies: opportunity for agroforestry in a 

warming Alaska. http://wflcweb.org/news_pdf/417_pdf.pdf. 

(18 October 2016).

Wolken, J.M.; Hollingsworth, T.N. 2012. Appendix 1: regional 

summaries—Alaska. In: Vose, J.M.; Peterson, D.L.; Patel-Weynand, T., eds. Effects of climatic variability and change on 

forest ecosystems: a comprehensive science synthesis for the 

U.S. forest sector. Gen. Tech. Rep. PNW-GTR-870. Portland, 

OR: U.S. Department of Agriculture, Forest Service, Pacific 

Northwest Research Station: 205–242.
Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions 147

Hawaii and the U.S.-Affiliated Pacific Islands

J.B. Friday, Kathleen Friday, and Craig Elevitch

J.B. Friday is the extension forester, University of Hawaii at Manoa, College of Tropical Agriculture and 

Human Resources Cooperative Extension Service; Kathleen Friday is the Forest Legacy/Stewardship 

program manager—Hawai’i and Pacific Islands, U.S. Department of Agriculture, Forest Service, Pacific 

Southwest Region, State and Private Forestry; Craig Elevitch is the director of Agroforestry Net.

Description of the Region

Hawaii and the U.S.-affiliated Pacific Islands (fig. A.1) include 

a diversity of traditional and modern agroforestry systems that 

have developed across a broad range of environments, from 

low coral atolls to high volcanic islands rising to 4,205 meters 

(m) (13,796 feet [ft]) in Hawaii. The peoples of Micronesia 

and Polynesia settled their islands as many as 4,000 years ago 

(Athens and Ward 2004) and brought with them a basic suite 

of agricultural plants. In the ensuing centuries, they developed 

highly sophisticated agroforestry systems tailored to meet food 

security needs within the local environments they inhabited. 

Having been developed on isolated islands and enduring for 

centuries or millennia, these agroforestry systems are models 

of sustainability (Clarke and Thaman 1993). Fertility is largely 

maintained by the recycling of nutrients, fallowing, and other 

ecosystem processes. Mulching is also practiced in many 

systems. Continuous soil cover prevents erosion. Because the 

species diversity and structure of tree-based multistory gardens 

are similar to native forests, these agroforests protect watersheds and water quality, both in streams and near the shore. 

The productivity over extremely long timeframes based only 

on local resources attests to their value as models for modern 

agroforestry systems that can be resilient to environmental 

stressors of the type that are projected to accompany climate 

change (table A.1).

The most common traditional system is a tree-based multistory 

system based on highly productive multipurpose species 

such as banana (Musa x paradisiaca) and coconut (Cocos

nucifera) (fig. A.2). The traditional staple crops, in addition 

to breadfruit, include taros (Colocasia esculenta, Alocasia

macrorrhizos, Cyrtosperma merkusii, and Xanthosoma spp.), 

yams (Dioscorea spp.), bananas (Musa x paradisiaca), and sweet 

Figure A.1. Map of Hawaii and the U.S.-affiliated Pacific Islands. (Figure from http://www.PacificRISA.org, used with permission).
148 Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions

Table A.1. Agroforestry practices that address threats and challenges. 

Pacific agroforestry system Threat/challenge addressed Mechanism

Multistory agroforest (including homegardens, 

shade coffee)

Intense rainfall and soil erosion Dissipates kinetic energy, surface litter, and tree roots 

with complex canopy.

Drought Provides more deeply rooted tree crops than annual 

crops.

Sea-level rise Allows upland agroforests to be less affected by 

sea-level rise than coastal farms.

Coastal strand windbreak (traditional) Salt spray Slows wind and blocks salt spray.

Storm surge, wave inundation Reinforces beach berm with roots.

Windbreaks in fields, orchards, pastures Increased storm intensity and frequency Dissipates wind energy.

Silvopasture Increased temperature extremes Provides shade for livestock.

Intensive tree leaf mulching to create organic 

soils for tree or annual crops

Drought, storm recovery Ameliorates sandy soils with organic material.

Taro paddies (mulched with tree/shrub foliage) Intense rainfall or drought Manages water use.

Figure A.2. A traditional agroforest on Palau. Crops include soft taro (Colocasia esculenta), giant taro (Cyrtosperma merkusii), 

avocado (Persea americana), banana (Musa x paradisiaca), papaya (Carica papaya), betel nut palm (Areca catechu), coconut palm 

(Cocos nucifera), and bamboo (Bambusa sp.). (Photo by J.B. Friday, University of Hawaii).
Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions 149

potato (Ipomoea batatas), with different crops being favored 

by different cultures and different environments (Kitalong 

2008, Raynor and Fownes 1991). Medicinal plants often 

include kava (Piper methysticum), betel nut (Areca catechu), 

and noni (Morinda citrifolia) and a diverse array of indigenous 

and introduced plants (Kitalong et al. 2011). Agroforests also 

include other useful species such as Pandanus tectorius, used 

for food and fiber, and timber species such as Calophyllum

inophyllum. These pan-Pacific trees and crops are adapted to a 

wide range of moisture regimes, although all are tropical and 

grow best in coastal environments. Since contact with Western 

civilization in the late 1700s, dozens of new species have 

been introduced and integrated into Pacific Island agroforests 

(Clarke and Thaman 1993). This additional species diversity, 

also called “agrobiodiversity,” can strengthen resiliency of 

agroforestry systems (Clarke and Thaman 1997). Most modern 

agroforests include fruit trees such as citrus (Citrus spp.), 

mango (Mangifera indica), avocado (Persea americana), and 

soursop and other Annona spp., which were introduced in 

modern times. Other modern cash crops that are sometimes 

incorporated into agroforestry systems include black pepper 

(Piper nigrum) and cacao (Theobroma cacao). On atolls and 

coastal areas of some high islands, farmers grow giant swamp 

taro (Cyrtosperma merkusii) in sandy soils in excavated pits 

by mulching heavily with leaves cut from native trees (Manner 

1993, 2010). Vegetation is usually preserved along coastlines 

(a practice now termed “coastal strand buffers”) and along 

streams (riparian buffers). Windbreaks are also important to 

protect more delicate plants from wind and salt spray. Shifting 

agriculture, with or without an enhanced forest fallow, is also 

practiced for some crops on high islands of Micronesia and on 

American Samoa (Manner 1993, 2014).

Traditional farmers across the Pacific have developed a stunning diversity of cultivars of their main crops. On Pohnpei in 

Micronesia, Raynor et al. (1992) found names for 177 cultivars 

of yams (Dioscorea spp.). Islanders across the Pacific have 

developed hundreds of cultivars of breadfruit (Zerega et al. 

2004). On Pohnpei alone, Ragone and Raynor (2009, in Balick 

2009) identified 48 cultivars of breadfruit. The high agrobiodiversity of Pacific Island agroforestry systems represents 

adaptation to different environments and also the provision of 

additional uses. Fownes and Raynor (1993) found that different 

cultivars of breadfruit on Pohnpei fruited during different 

months and thus, by growing different cultivars, farmers were 

able to extend the breadfruit season. By having a range of 

varieties that can be harvested year round, it is more likely 

that some of the total harvest will be spared from the effects of 

extreme weather conditions or events. Englberger et al. (2009, 

in Balick 2009) estimated that about 50 cultivars of bananas are 

grown on Pohnpei. Englberger et al. (2004, 2006) showed that 

some traditional cultivars of banana were rich in carotenoids 

and vitamin A and could play an important role in addressing 

local nutrition problems caused by an overreliance on refined, 

imported foods. Despite the increasing importance of imported 

foods such as rice, bread, and canned meat, islanders still enjoy 

and, in part, depend on locally produced foods, which are 

seldom marketed commercially but are usually locally available 

through family connections (fig. A.3). The wide range of 

varieties and cultivars that still exist within and between islands 

provides options for changing environmental conditions.

A number of acres on the Pacific islands, representing from 2 to 

85 percent of the total forest area on the islands, are dedicated 

to multistrata agroforests (table A.2). There are still many areas 

potentially suitable for agroforestry on the islands (table A.2).

Figure A.3. Locally grown agroforestry crops for sale at a market on Yap Island, Federated States of Micronesia. Crops include 

watermelon (Citrullus lanatus var. lanatus), taro (Colocasia 

esculenta), calamansi (Citrus microcarpa), soursop (Annona 

muricata), chili peppers (Capsicum sp.), pineapple (Ananas 

comosus), several varieties of bananas (Musa x paradisiaca), 

passion fruit (Passiflora edulis), breadfruit (Artocarpus altilis), 

and Tahitian chestnut (Inocarpus fagifer). (Photo by J.B. Friday, 

University of Hawaii).
150 Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions

Table A.2. Extent of current and potential agroforests on Pacific Islands. 

U.S.-affiliated Pacific Island jurisdiction Total area 

(acres)

Population 

(2010)

Multistrata agroforest

Potentially appropriate for agroforestry 

(not currently in forest or agroforest) 

(acres)

Acres

Percent 

of total 

forest

Savanna, other 

shrubs and 

grassland, 

and disturbed 

vegetation

Cropland Total

Hawaiia 4,127,337 1,360,301 770,085 174,042 944,127

American Samoa (U.S. Territory) 49,280 55,519 15,510b 35 715c

Republic of the Marshall Islandsd 44,800 67,182 20,000 85 1,134 1,134

Federated States of Micronesiae 149,804 106,836 35,655 25 11,852 195 12,047

Commonwealth of the Northern Mariana Islandsf 113,280 53,883 1,313 3 13,372 918 14,290

Guam (U.S. Territory)g 135,680 159,358 1,921 2 44,455 44,455

Republic of Palau 114,560 20,956 2,740h 4 15,329i

a

 U.S. Department of Agriculture (2012).

b Cole et al. (1988).

c

 Donnegan et al. (2004b).

d Donnegan et al. (2011c).

e

 Donnegan et al. (2011b).

f

 Donnegan et al. (2011a).

g

 Donnegan et al. (2004a).

h

 Cole et al. (1987).

i

 Donnegan et al. (2007).

Note: Blank cells indicate data are not available.

Characteristics of Agroforestry Systems

Pacific Island agroforestry systems can be highly productive. 

Fownes and Raynor (1993) calculated that the Pohnpeian 

agroforestry system produced more than 6 metric tons/

hectare (ha)/year (2.7 tons/acre/year) of breadfruit alone plus 

significant yields of starches such as yam, taro, and other crops. 

Tree-based systems typically have a much higher standing 

biomass and total carbon storage per unit area than do annual 

crops. The high perennial biomass results in systems that are 

both more resistant to change than annual cropping systems 

and more resilient in the face of change. For example, fruit 

trees may drop fruits during a drought, but the trees will usually 

remain in condition to produce when rainfall returns.

The high agrobiodiversity of Pacific Island agroforestry 

systems also increases resistance and resiliency. Evidence indicates that those systems resist (through diversity) and recover 

from (through fallow) insect and disease problems better than 

monocultures do (Ferentinos and Vargo 1993). It is hoped that 

these systems will also resist and be resilient to climate change. 

If environmental stressors caused by climate change (changes 

in rainfall, temperatures, or seasonality of flowering and 

fruiting) cause some crops or varieties to fail, other crops in the 

system can take their place. For example, if increased groundwater salinity makes cultivation of Colocasia taro infeasible, 

farmers could switch to cultivating Cyrtosperma taro, which 

is generally regarded as being more salt tolerant. Agroforestry 

systems in the Pacific have a complex spatial structure, both 

vertically and across the landscape. The complex structure 

may lead to improved resistance to change, because the system 

creates the microclimates for some of the plant species (for 

example, shade for understory crops). The danger also exists, 

however, that some microclimates may disappear entirely from 

some islands as climates change globally, taking with them 

adapted crop species.

Potential of and Limitations to Agroforestry

Hawaii has significant areas of cropland and pastureland with 

windbreaks and potential for additional windbreaks. Hawaii’s 

major plantation crops (sugar and pineapple) have been greatly 

reduced in acreage, and the land released is still in a dynamic 

state, with potential for increased combinations of orchard 

and even multistory agroforest. Pasturelands and rangelands 

in Hawaii, Guam, and the Commonwealth of the Northern 

Mariana Islands are ecologically suitable for forest and could 

be restored to forest or partial forest cover with silvopastoral 

techniques. The potential to return savanna, secondary vegetation, and other shrubs and grasslands to productivity through 

agroforestry varies with land tenure, soil fertility, and slope. 

The “potentially appropriate” acreage figures in table A.2 have 

not been reduced for those factors.

Despite the productivity, resistance, and resilience of traditional agroforestry systems, a major drawback has been low-cash 

productivity. Most agroforestry products are subsistence foods 

such as breadfruit, taro, and yams. Farmers across the Pacific 

frequently neglect traditional agroforestry systems to seek cash 

employment or convert agroforests to cash crops.
Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions 151

Traditional agroforests can be enriched with high-value 

crops to perpetuate these resistant and resilient systems while 

increasing economic output. Examples of cash crops include 

black pepper (Piper nigrum) and sakau or kava (Piper methysticum) on Pohnpei (Merlin and Raynor 2005). Some traditional 

subsistence plants such as coconut can also be used to produce 

products for sale, such as oil or baskets, if markets exist. As 

more islanders find cash employment in the market economy, 

markets for traditional food crops such as yams are developing 

in population centers, giving farmers another way to earn some 

cash (Ames et al. 2009). Public campaigns to emphasize the 

nutritional values of traditional foods (Englberger and Lorens 

2004) can also encourage farmers to perpetuate agroforestry 

systems, and, in some places, traditional crops have entered the 

cash market.

Threats and Challenges to Agricultural 

Production and Community Well-Being

Climate change is expected to affect island agroforestry with 

higher temperatures, changes in precipitation, increased storm 

intensity (wind and rainfall), and salinization of groundwater, 

depending on the region (ABM and CSIRO 2014) and local 

topography. To date, the effects of long-term climate change 

are difficult to measure and separate from natural medium- and 

short-term variability. Declines in rainfall in Hawaii during the 

past century are attributed to climate change but may have been 

caused partially by volcanic emissions for the past few decades 

(Giambelluca et al. 2013). The Pacific Decadal Oscillation and 

the El Niño—Southern Oscillation (ENSO) variously affect sea 

level, storms, and drought, and Pacific islands are characterized 

by high natural variability as a result. “ENSO-related precipitation variability on regional scales will likely intensify with 

long-term global warming” (IPCC 2014).

Sea levels around the western Pacific have risen at rates double 

or more than double the global averages during La Niña-dominated conditions since 1993 (Keener et al. 2012). In 2014, 

conditions changed with the apparent onset of El Niño conditions. The National Oceanic and Atmospheric Administration 

observed that “the below average sea level in Micronesian 

waters is a huge shift from very high sea levels only a few 

months ago, and indeed, for most of the past decade” (NOAA 

2014). Sea-level rise is expected ultimately to inundate Pacific 

Island coastal areas and atoll islands. The highest point on most 

atolls is typically 2 to 3 m (6 to 9 ft) above sea level. Within a 

generation, the freshwater lenses that underlie atolls and many 

coastal areas will shrink in volume and/or become increasingly 

saline as a result of the dynamic interplay between rising sea 

levels, drought, ocean water inundation events, and overpumping wells. Increased groundwater salinity may reduce or 

eliminate the ability of low coral islands to support breadfruit 

and taro (Manner 2014). Storms will also deposit coralline 

material on land in a natural process of island-building (Lobban 

and Schefter 1997); however, even where the elevation of the 

land is thus increased and might seem to balance sea-level rise, 

it does not result in a steady state with respect to agriculture, 

because each disturbance event depositing gravel or saltwater 

requires a significant recovery period before agriculture again 

becomes productive.

Typhoons and tropical storms such as super typhoon Pongsona 

in Guam in 2002, Typhoon Sudal in Yap in 2004, Typhoon 

Bopha in Palau in 2012, and Hurricane Iselle in Hawaii 

in 2014 are particularly destructive to small islands. The 

Intergovernmental Panel on Climate Change (IPCC) (IPCC 

2014) predicts that “extreme precipitation events... over wet 

tropical regions will very likely become more intense and more 

frequent.” Upland agroforestry systems will be damaged by 

high winds, and coastal systems may be highly degraded by 

storm surges. Although the forest cover provided by agroforestry protects against surface erosion, heavy rainfall can cause 

mass wasting events that devastate entire watersheds, as when 

Typhoon Chata’an caused several hundred landslides in Chuuk, 

including many that carried away the entire agroforest and soil 

horizon from some plots and inundated other plots with debris 

and mud (USGS 2002).

Droughts often occur in the Pacific under El Niño conditions 

and, under climate change, may increase in frequency and 

intensity, even though average rainfall is predicted to increase 

on most islands. Droughts may be particularly severe on coral 

atolls and the leeward sides of high islands such as Hawaii 

(Keener et al 2012). Guam and the Northern Marianas Islands 

already have seasonally dry climates (Mueller-Dombois and 

Fosberg 1998). The Northern Marshall Islands experienced a 

severe drought during 2013 and 2014, which resulted in the 

loss of much of the breadfruit crop. Tree-based agricultural 

systems, although resistant to moderate changes in climate, can 

be pushed past a breaking point when shifts in temperature and 

precipitation are so severe that the trees die, causing catastrophic 

losses. Droughts will also lead to increases in wildfires, which 

damage native forests and agroforests on the drier islands of the 

western Pacific, including Guam, Palau, and Yap.

Invasive plants, pests, and diseases brought to the Pacific Islands 

as a result of increased transportation and migration threaten 

the sustainability of agroforestry systems. Changing climates 

and the interaction with other disturbance may exacerbate the 

competition of nonnative species with native and traditionally 

cultivated species.

Finally, loss of traditional knowledge of cultivation techniques 

and cultivars is an important threat to Pacific Island agroforestry 

systems. Loss of knowledge is exacerbated by movement into 

towns and cities for jobs and migration from smaller islands 
152 Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions

to larger ones, including to Hawaii and Guam and also to 

the mainland United States. In part, migration is fueled by 

concerns of climate change.

Conclusions

Pacific Islanders recognize the need to adapt to shifting weather 

and climatic conditions. The traditional agroforestry systems 

are not static and have evolved to take advantage of new plants, 

new markets, and new methods of cultivation since western 

contact. A major need is for cultivars that are more drought and 

salt tolerant and new methods of cultivation, because it is likely 

that drier and more saline conditions will prevail in the future 

(Friday 2011). Because these systems exist across the Pacific, 

farmers on wetter islands may be able to learn from those living 

on drier islands today. Recognizing the increased threat from 

sea-level rise and storm surges, islanders have expressed needs 

for plants for coastal stabilization and windbreaks and systems 

that are more resistant to damage by storms. Addressing these 

new threats is an appropriate job for Pacific Island universities 

and local agriculture and natural resource agencies. Often these 

efforts are facilitated through farmer-led research and training, 

especially farmer-to-farmer programs. On small islands, it 

is particularly evident how agriculture is linked to nutrition, 

employment, and economic activity. Establishing and nurturing 

traditional agroforestry systems to enhance their resiliency to 

climatic variability and food security will have benefits across 

society.

Key Information Needs

• Documentation of traditional agroforestry systems and 

knowledge of indigenous Pacific Islanders regarding growth, 

phenology, and management of these systems.

• Better agroecological understanding of how to apply 

agroforestry at farm and landscape levels to address various 

climate change scenarios and establishment on degraded or 

abandoned lands within the Pacific Islands.

• Development of methodologies to identify and manage for 

invasive species that are increasingly affecting agroforestry 

and other plant systems in the Pacific Islands.

• Identification of current economic and cultural impediments 

to adoption and retention of island agroforestry practices 

and of practical interventions that can enhance agroforestry’s 

appeal and use.

• Development of tools that can help assess differences in 

production and natural resource services in conventional 

monocropped systems and agroforestry systems under 

changing climatic conditions.

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154 Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions

Northwest

Badege Bishaw and Kate MacFarland

Badege Bishaw is the program director and senior instructor in the Department of Forest Ecosystems 

and Society, Oregon State University; Kate MacFarland is an assistant agroforester, U.S. Department of 

Agriculture (USDA), Forest Service, USDA National Agroforestry Center.

Description of the Region

The Northwest is a region of dramatic physical and environmental contrasts, ranging from high alpine ecosystems to moist 

lowland rainforests and high deserts. Land uses and opportunities for agroforestry vary accordingly. Proximity to the Pacific 

Ocean and elevation are the major climatic influences. Rain 

shadows lie east of the Cascade, Olympic, and Coast Ranges 

and, west of the mountains, heavy rainfall and moderate 

temperatures prevail (Hardesty and Lyon 1994).

Agriculture is important to the Northwest’s economy, environment, and culture. Agriculture contributes 3 percent of the 

Northwest’s gross domestic product, crop and pasturelands 

comprise about one-fourth of Northwest land area, and farming 

and ranching have been a way of life for generations. Wheat, 

potatoes, tree fruits, hazelnuts, vineyards, and more than 300 

minor crops and also livestock grazing and confined animal 

feeding operations, such as beef and dairy, depend on adequate 

water and particular temperature ranges (Dalton et al. 2013). 

During the past century, the average annual temperature 

increased by 1.5 °F, with increases in some areas up to 4 

°F. Changes in snowpack, streamflows, and forest cover are 

already evident (USGCRP 2009). Future climate change will 

likely continue to influence agriculture. The average annual 

temperature in the region is projected to increase by 3 to 

10 °F by the end of the century (USGCRP 2009). Winter 

precipitation is projected to increase, but summer precipitation 

is projected to decrease, though precipitation projections are 

less certain than those related to temperature (USGCRP 2009). 

Pressures related to the rapidly growing population in this 

region would compound future climate change impacts.

Higher temperatures, changing streamflows, and increases in 

pests and disease threaten forests, agriculture, and fish populations in the Northwest (USGCRP 2009). Decreasing supplies 

of water for irrigation, increasing incidents of pest and disease 

attacks, and growing competition from weeds threaten Northwest agriculture, particularly the production of tree fruits, such 

as apples and wine grapes (USGCRP 2009). Human activities 

already threaten Northwest salmon populations and climate 

change impacts would add stress. Lower summer streamflows 

and warmer stream and ocean temperatures are less favorable 

for salmon and other cold-water fish species.

Agroforestry practices that integrate animal husbandry, crop rotations, and fallow periods have long been part of the heritage 

of North American peoples (Bishaw 2013; Davies 1994). In 

the Willamette Valley, Oregon, the Kalapuya managed oak 

savannas, vast woody huckleberry shrubs, and forests while 

also managing crops, including camas and wapato (Goodness 

2011). Prescribed burning was a tool most Pacific Northwest 

tribal communities used to maintain and enhance prairie 

edges and oak woodland savannas for vegetation and wildlife 

management for various food and cultural resource products 

throughout western Washington and Oregon (Anderson 2007). 

The Pacific Northwest tribal communities also managed soil 

fertility.2

 They gathered food, medicine, and other supplies 

in a rotational basis for sustained harvests. This management 

process, enforced by tribal leaders (Anderson 2007; Goodness 

2011),3 was conducted by “skilled and knowledgeable applied 

ecologists who actively managed the land” (Bainbridge 1995: 

147). Some of these management practices, collectively 

referred to as traditional ecological knowledge (TEK), are 

ongoing today. This regionally specific body of knowledge has 

tremendous potential for supporting sustainable agroforestry 

development in the Northwest.

The most common agroforestry practices in the Northwest 

region include silvopasture, riparian buffers, forest farming, 

mixed-practice agroforests, alley cropping, and windbreaks. 

Silvopasture is used primarily for economic production. 

Riparian buffers are implemented to address water pollution, 

create fish habitat, and control erosion. Forest farming is often 

used for producing mushrooms, floral greenery, and juniper 

berries. Agroforests use woody crops as part of whole-farm 

crop and income diversification systems. Windbreaks are used 

to protect high-value crops and animals. Each of these practices 

sometimes integrates bioenergy crops. These practices increase 

income and biological diversity in the region and protect 

against water and wind erosion (Bishaw 2013). In 1990, 

researchers surveyed nonindustrial private forest landowners in 

2

 Petrie, M. [N.d.]. The land management practices of Coos, Lower Umpqua, and Siuslaw Indians. Term paper for RNG 477 agroforestry course. 

Corvallis, OR: Oregon State University. 

3

 Petrie, M. ([N.d.]).
Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions 155

Washington State and found that 57 percent practiced agroforestry (Lawrence et al. 1992). Although many landowners in 

this region may not identify themselves as agroforesters or as 

practicing agroforestry, they are often engaged in practices that 

may be considered agroforestry.

Silvopasture

Silvopasture in the Northwest involves many forms, including 

grazing native understory vegetation in young commercial 

forests and woodlands, tree/livestock production in forested 

rangelands, and livestock/timber production in thinned, midrotation forests. Livestock grazing is the primary agricultural 

use of approximately 1 million hectares (2.5 million acres) 

of hill land in western Oregon (Sharrow 1993; Sharrow and 

Fletcher 1994). In Washington, a survey of nonindustrial 

private forest landowners found 39 percent of respondents 

practiced forest grazing; among respondents in eastern Washington, 47 percent practiced forest grazing (Lawrence et al. 1992). 

Although silvopasture differs from forest grazing commonly 

practiced in the Northwest (particularly on public lands), an 

opportunity exists for this agroforestry practice to expand. This 

change would require more intentional, intensive management 

of trees, forage, and livestock. Research specific to western 

Oregon has found that silvopastures may be more efficient at 

sequestering carbon than forest plantation or pasture monocultures (Sharrow and Ismail 2004).

Sheep grazing is a traditional use of temperate coniferous 

forests in the United States and Canada. Like any management 

tool, prescription sheep grazing can be misused. Properly applied 

sheep grazing often reduces competition between trees and 

other ground vegetation, thus increasing tree growth (Sharrow 

1994). Conifers on grazed plantations in western Oregon had 

increased height and diameter growth, averaging 63 centimeters 

(cm) (25 inches [in]) taller and 0.7 cm (0.3 in) greater in diameter 

at breast height than the nongrazed plots after 12 years of plantation 

growth (Jaindl and Sharrow 1988). This long history of sheep 

grazing in forests in the Northwest also indicates opportunities 

for increased silvopasture applications.

Riparian Buffers

Riparian forest buffers in crop and grazing lands have gained 

increasing attention in the Northwest because of popular 

demand and regulation to protect salmon and steelhead. In 

Oregon, this attention has also come through the Governor’s 

Salmon and Watershed Restoration initiatives (Independent 

Multidisciplinary Science Team 1999; Nicolas 1997). The 

focus during the past 15 years of riparian land use in Oregon 

has been to achieve water quality and restore aquatic habitats 

(Riparian Management Work Group 2000; Bishaw et al. 2002). 

These efforts seeking to lower stream temperatures using shade 

and to enhance fish habitat through large woody debris are only 

more critical with climate change projections. These efforts 

have been ongoing in Washington also, with requirements for 

streamside buffers in forest lands through the Salmon Recovery 

Act of 1999 (Engrossed Substitute House Bill (ESHB) 2091 

[1999]) and the resulting Forest Practices Habitat Conservation 

Plan passed in 2006 and also with voluntary buffer programs 

on agricultural lands (Washington State Department of Natural 

Resources 2015). In July 2014, the U.S. Environmental 

Protection Agency began requiring Washington State to include 

conditions in Federal pass-through grants that require projects 

to be consistent with National Marine Fisheries Service buffer 

guidance to help protect and recover Washington’s salmon runs 

(Washington State Department of Ecology 2013).

Both State and Federal Governments currently offer incentive 

programs to encourage landowners to establish riparian forest 

buffers. In Oregon, between 1999 and 2012, Federal and 

State Governments spent $18 million USD to establish more 

than 40,300 acres of riparian buffers (Oregon Watershed 

Enhancement Board 2012). Other State and nonprofit organizations, particularly watershed councils, are also involved in 

establishing riparian forest buffers, both through regulatory and 

voluntary incentive programs (Cochran and Logue 2011; Lurie 

et al. 2013). Currently in development in Washington State, the 

Puget Sound Working Riparian Buffer Feasibility Study project 

is seeking to provide best available science on agroforestry 

strategies specific to enhancing ecosystem service function 

within Puget Sound watersheds. The project goal is to work 

with local tribes, regulatory agencies, and the agricultural community to provide a policy and implementation framework for 

allowing for the management of native and nonnative species 

within the riparian buffer corridors as opposed to the “no-touch” 

buffer framework that is currently enforced. Throughout the 

Northwest region, riparian forest buffers, if properly practiced 

and managed, have great potential to improve water quality and 

create favorable fish habitat in the region, promoting adaptation 

to the impacts of field runoff created by extreme precipitation 

events and unfavorable temperatures.

Forest Farming

Forest farming, also called multistory cropping, is a practice in 

which existing forest stands are intentionally and intensively 

managed to create an appropriate environment for growing 

understory crops. The chanterelle mushroom harvest from 

Pacific Northwest forests is a multimillion-dollar industry, yet 

managers, harvesters, and scientists lack a current synthesis 

of information about chanterelles. Because chanterelles grow 

symbiotically with the roots of forest trees, managing the fungi 

for sustainable harvests also means managing forest habitats 

(Pilz et al. 2003). Research on the biology, ecology, and management of truffle fungi in the Northwest has increased interest 
156 Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions

in forest farming and forest gardening systems that combine 

trees and truffles (Trappe et al. 2009). Along with a variety of 

other mushrooms, other nontimber forest products harvested in 

the Northwest include fruits (such as huckleberries), decorative 

woody florals, and medicinal plants (such as Oregon grape 

and elderberries). Many of these are harvested from naturally 

occurring stands.

Forest farming provides a significant opportunity to increase 

the harvest of these nontimber forest products while ensuring 

their sustainability. Some researchers have studied the design 

of agroforestry systems that integrate high-quality timber and 

matsutake mushroom production in the Cascade Range of 

southern Oregon. These systems could also produce ornamental 

conifer boughs, pine cones, and Christmas trees (Weigand 1998). 

Forest farming, however, has not been widely implemented. 

Forest farming enterprises could prove profitable for family 

forest owners in the Northwest.

The projected shifts in temperatures and precipitation that 

threaten forests are likely to also affect forest-farming systems. 

These projected impacts include greater fire risk, decreasing 

tree growth, and increasing insect attacks (USGCRP 2009). 

Climate change impacts on nontimber forest products cultivated through forest farming systems, however, are not well 

understood.

Agroforests

Agroforests include the management of forests on farmlands. 

Agroforests are a complex mix of trees and shrubs, often 

incorporating multiple agroforestry practices on one parcel. 

This system has high levels of biodiversity and achieves the 

ecological dynamics of a forest ecosystem (Michon and de Foresta 1999). Farm diversification requires a holistic landscape 

approach. Diversifying a farm with woody crops involves 

intentionally integrating trees into the farming system. Practices are designed for the conditions and needs of specific parcels 

of land, to integrate and create interaction between crops and 

trees, and to use the management skills of the landowner. Such 

plantings meet landscape integration criteria for agroforestry. 

These woody perennials enhance biodiversity, diversify 

producer income, minimize risk, generate alternative profits, 

and create a more integrated and visually appealing land use 

system that may be more environmentally, economically, and 

socially sustainable than the original farm (Angima 2009). For 

example, converting 40 acres of marginal agricultural land to 

incorporate hybrid poplar, hazelnut, or Christmas trees through 

alley cropping, windbreaks, or other practices introduces trees 

and shrubs into the whole farm system. Research evaluating 

the level of resources and habitats for important beneficial 

insects has benefited some agroforestry systems (Russell 2013). 

Agroforestry practices also can increase beneficial insect 

habitat and resources. This diversified agroforestry approach 

may be particularly suitable to the smaller scale farms in the 

region. Diversified operations may be more resilient to weather 

variability caused by climate change.

Alley Cropping

Alley cropping is an agroforestry practice in which agricultural 

or horticultural crops are grown in the alleyways between widely 

spaced rows of woody plants. Alley cropping can diversify 

farm income, increase crop production, improve landscape 

aesthetics, enhance wildlife habitat, and provide protection and 

conservation benefits to crops. By combining annual and perennial crops that yield multiple products and profits at different 

times, a landowner can use available space, time, and resources 

more effectively. Although alley cropping can increase soil 

organic carbon, yield decreases to the primary crop grown 

between the rows can be significant, constraining the appeal of 

alley cropping (Seiter et al. 1999). Some hazelnut growers in 

the Northwest plant snap beans or other crops between newly 

planted trees (Hazelnut Marketing Board 2013). Apple growers 

in Hood River and the Willamette Valley historically planted 

strawberries between apple rows (Fortier 1940).

The Northwest’s orchards and vineyards may provide some 

innovative opportunities for alley cropping systems, if growers 

are interested in adding crops for soil retention, pollination, 

or income production reasons. In particular, the extensive 

hazelnut orchards in the Northwest may allow for opportunities 

for alley cropping additional crops between the rows of existing 

or new orchards. Relatively few studies clearly show how alley 

cropping or agroforestry systems contribute to managing the 

risks from climatic variability, which include the potential to 

reduce available winter chilling days and crop yields. Luedeling 

et al. (2011) projected climate change effects on winter chill, 

an agroclimatic factor that affects agroforestry systems that 

include temperate fruit trees. These models project sufficient 

winter chill in the Northwest, which may shift more fruit 

growing to this region from regions that will not have sufficient 

winter chill. Concerns remain, however, about early bud break 

followed by a freeze that could potentially kill the developing 

buds or flowers. These concerns call for more research on 

fruit and nut trees’ adaptations to climate change and also on 

the potential development of new or existing cultivars more 

resilient to these stressors.

Windbreaks

In some parts of the Northwest, particularly the Columbia 

River Gorge and coastal areas, windbreaks play an important 

role in protecting agricultural enterprises from harsh winds. 

This protection is particularly important for high-value crops 
Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions 157

grown in the region, such as fruit, wine grapes, and vegetables. 

Livestock are also affected by wind. Hedgerows are also 

common in western Oregon, particularly among those landowners interested in sustainable farming methods. Oregon State 

University Cooperative Extension has released publications 

that suggest hedgerows can enhance the beauty, productivity, 

and biodiversity of farms in the region (Hobbs and McGrath 

1998). Washington State University’s Tree Fruit Research and 

Extension Center reported bees are more numerous in orchards 

having windbreak protection (Hanley and Kuhn 2003). 

Windbreaks are also used in the region as living snow fences 

to protect roads, communities, and livestock (Hanley and Kuhn 

2003). With effective planting and management practices, it 

is possible to establish windbreaks and hedgerows to provide 

ecological and economic benefits to landowners and to address 

climate change in the Northwest.

Special Uses

Agroforestry practices can be designed to produce certain 

specialty products. Short-rotation biomass species are one 

specialty product that can be incorporated into agroforestry 

design. Advanced Hardwood Biofuels Northwest (AHB) grows 

hybrid poplar trees to demonstrate the latest biofuel development in the region. AHB is a “consortium of university and 

industry partners led by the University of Washington. AHB is 

working to prepare Washington, Oregon, Northern California, 

and Northern Idaho for a sustainable hardwood bioproducts 

and biofuels industry” (AHB 2014). The longer term goal is 

to develop poplar-based biofuels, including jet fuel, diesel, 

and gasoline that can supplement existing fossil fuels (AHB 

2014). These species could be integrated into existing or new 

agroforestry systems.

Northwestern tribal communities are active in conserving and 

managing their natural resource base. This management is 

carried out in part through tribal natural resources agencies. 

Some of the agroforestry practices discussed in the region may 

overlap with TEK and management strategies. These practices 

may help preserve and maintain this TEK and can also provide 

substantial economic development and food sovereignty 

potential for tribal communities (Anderson 2007).

Problems and Limitations

Agroforestry is widely underexploited for both the production 

of goods and environmental services in the Northwest. Priorities include developing regional and site-specific practices and 

demonstrations of the ecological and economic performance of 

various agroforestry practices. The benefits of riparian buffers 

and effective planting strategies need to be developed and 

verified. Evaluation of options and impacts of the following 

should be assessed: (1) forest grazing compared with establishing silvopasture systems and (2) wild harvesting of nontimber 

forest products compared with forest farming.

Interest in agroforestry in the Northwest is expected to grow 

as increasing emphasis is placed on land stewardship and 

environmental protection in agroecosytems in the region. The 

potential of agroforestry to simultaneously provide economic, 

environmental, conservation, and social benefits is rapidly 

being recognized by Federal and State agencies, universities, 

and conservation organizations. Despite its potential, however, 

numerous barriers have impeded the development and application of agroforestry in the Northwest. The challenges surrounding agroforestry are that it is unconventional, lacks recognition, 

and cuts across agencies and disciplines. In addition, the large 

equipment used by producers in large-scale crop production may 

not be compatible with what is needed to install and maintain 

agroforestry practices. Agroforestry may also have higher labor 

requirements than existing large-scale crop-production systems. 

Current agroforestry research and development and related 

extension activities are limited, disconnected, and minimally 

funded in relation to the need and interest.

Agroforestry can address many important natural resource concerns in the region. Water-quality problems can be addressed 

with agroforestry practices such as riparian forest buffers that 

increase stream protection to reduce erosion, capture agricultural chemical pollutants, provide shade to cool stream temperatures, provide thermal protection for wildlife, and improve 

drinking water. Agroforestry practices used as climate-change 

adaptation and mitigation tools should be explored at the 

watershed and landscape levels to optimize integrated land-use 

systems and provide landowners with products and ecosystem 

services. Riparian buffers and hedgerows can provide habitat to 

improve the health of bees and other pollinators in the region. 

These pollinators are very important for food crop production, 

which is heavily centered on pollinator-dependent fruits and 

vegetables in some parts of the region. New markets can create 

opportunities for agroforestry products. For example, vineyards 

could have salmon-safe certification for their value-added 

products and edible fruits, and nontimber forest products could 

be grown in riparian areas. Agroforestry can also help with 

diversifying income sources for rural communities and make 

farmers more economically and ecologically resilient while 

coping with climate variability and change.

The Northwest faces some limitations specific to the region. 

The region is very diverse ecologically and agriculturally, 

which may limit the abilities of landowners from across this 

region to learn from one another. What practices and species 

work in one part of the region may not work in another part. 

This diversity may make the development of interest groups 

related to agroforestry more difficult. In addition, significant 
158 Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions

portions of these States are publically owned. These forested 

areas largely cannot be managed using agroforestry practices, 

though recent interest in landscape-scale conservation may 

increase the appeal of agroforestry for its ability to work across 

landownerships.

Although riparian forest buffers are strongly encouraged 

because of salmon and other fish species concerns, some of 

these riparian buffers are “no touch” and do not allow for 

any harvesting. This policy may make their implementation 

more challenging and limit the integration of nontimber forest 

products into these buffers. The region also has a shortage of 

trained professionals in agroforestry to disseminate the many 

economic benefits and ecological services of agroforestry to 

landowners. Strengthening partnerships and cooperation among 

agencies and forming alliances among Federal, State, university, and private sectors will help develop, disseminate, and 

apply agroforestry. The establishment of the Pacific Northwest 

Agroforestry Working Group brings together agroforestry 

professionals to conduct joint research and training and will 

help remove the barriers between agencies and universities 

and create cooperation among scientists, natural resources 

professionals, and landowners.

Key Information Needs

• Ecological and economic performance of various agroforestry practices, as determined by site-specific research and 

demonstration.

• Site-specific adaptation of agroforestry practices by landowners that reflects the tremendous diversity of sites and 

conditions in the Northwest and limited technical resources.

• Benefits of riparian buffers and effective planting strategies 

among landowners. 

• Long-term impacts of silvopasture and harvesting of 

nontimber forest products. 

• Cultural practices for the sustainable production of nontimber forest products.

• Potential of alley cropping systems with existing and new 

growers.

Literature Cited

Advanced Hardwood Biofuels Northwest (AHB). 2014. About 

hardwood biofuels Northwest. http://hardwoodbiofuels.org/

about/. (20 October 2016).

Anderson, M.K. 2007. Indigenous uses, management, and 

restoration of oaks of the far Western United States. Technical 

Note No. 2. Davis, CA: U.S. Department of Agriculture, Natural 

Resources Conservation Service, National Plant Data Center. 

24 p.

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160 Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions

Southwest

Dan Neary, Gary Bentrup, and Michele Schoeneberger

Dan Neary is a supervisory research soil scientist, U.S. Department of Agriculture (USDA), Forest Service, 

Rocky Mountain Research Station, Flagstaff Forestry Sciences Laboratory; Gary Bentrup is a research 

landscape planner, USDA Forest Service, USDA National Agroforestry Center; Michele Schoeneberger is 

research program lead and soil scientist (retired), USDA Forest Service, USDA National Agroforestry Center.

Description of the Region

The Southwest is a region defined by water scarcity. Composed 

of Arizona, California, Colorado,4 Nevada, New Mexico, 

and Utah, this region has some of the greatest landscape and 

climate diversity in North America (Neary and Ffolliott 2005, 

Warshall 1995). Federal and tribal lands dominate the Southwest, with croplands comprising only 8 percent of the region 

and with the majority being located in California and eastern 

Colorado (fig. A.4) (USDA NRCS 2013). Agriculture is mainly 

confined to intermontane valleys, the broad plateaus, and 

plains with adequate groundwater resources or along alluvial 

river systems fed by mountain snowmelt. Major river systems 

like the Colorado, Rio Grande, and Sacramento-Feather-San 

Joaquin supply water to many areas with irrigated agriculture. 

Figure A.4. Federal and tribal lands comprise much of the 

region, with cropland and pastureland limited to areas with 

available water resources. Rangeland grazing occurs on Federal 

and tribal lands and also on private rangeland (on some of the 

areas shown in white). Agricultural land data from Homer et 

al. (2015) and Federal and tribal land data from USDOI USGS 

(2003).

Much of the cropland in the region, outside of California, is 

dedicated to growing alfalfa hay. Other crops include cotton, 

lemons, lettuce, onions, peanuts, peppers, potatoes, tangerines, 

and wheat (USDA NASS 2014). Together with hay production, 

agriculture accounts for 79 percent of the water consumption 

(Garfin et al. 2014). This usage, however, is changing as 

urbanized areas such as Phoenix expand by securing the 

rights to agriculture water. The Phoenix metropolitan area 

has transitioned from being agricultural in the 1960s to being 

predominantly urban in the 21st century.

California is different from the rest of the Southwest because 

it ranks first in the United States for agricultural production, 

with a value in excess of $42.6 billion or 10.8 percent of the 

Nation’s total agricultural sales (USDA NASS 2014). This 

amount is about 2.6 times the economic production of the 

rest of the region combined. Approximately 28 percent of 

California’s agricultural sales is from livestock products, and 

the remainder is from traditional crops such as vegetables, fruit, 

grapes, nut crops, lettuce, and berries (USDA NASS 2014).

Rangelands comprise the largest portion of Federal and 

non-Federal land area in the Southwestern United States (USDA NRCS 2013), generating agricultural revenue through dairy 

and livestock production (USDA NASS 2014). Rangelands in 

the region are diverse and encompass different ecotypes from 

oak savanna, sagebrush steppe, and scrubland to arid grasslands 

(Shiflet 1994).

Forests of the region occur on rugged peaks and low ranges, 

over broad plateaus and isolated mesas, and along minor and 

major river systems (table A.3). These systems provide many 

ecosystem services crucial to water resource availability. 

Simultaneous production of wood for fiber or other tree-based 

benefits, forage for livestock, and traditional agricultural products has been a historical land management objective in the 

Southwestern United States. Livestock grazing occurs on many 

forest types in the region; however, these production systems 

may not necessarily be considered silvopasture systems by 

definition and practice. (See box A.1.)

4

 Eastern Colorado is best described by the conditions and considerations discussed in the Great Plains regional summary in this appendix.
Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions 161

Table A.3. Forests of the Southwest Region.

Forest type Extent Forest management as It pertains to agroforestry

Southern Rocky 

Mountain forests

10.1 million ha (24.9 

million ac) of mountainous 

terrain in Colorado, New 

Mexico, Arizona, Utah, 

and parts of Nevada.

Forage increases as forest density decreases and vice versa, making timber management a 

forage management tool (Clary and Ffolliott 1966). Prescribed fire is also a tool being used 

more recently to eliminate undesirable plants. Utilization of 30 to 40 percent of the forage 

growth provides a sustained level of forage resources for livestock on rangelands in good condition. Continuous yearlong grazing is practiced on lower-elevations in the southern part of the 

region. Fencing, strategic placement of stock tanks and salt licks, and constructing driveways 

to move livestock from one allotment to another are used to improve livestock distribution, 

attain specified stocking levels, and obtain more uniform utilization of forage resources.

Sierra coniferous 

forests

6.9 million ha (16.9 

million ac) of mountain 

landscapes in California 

with minor occurrences in 

Nevada.

Forage production increases rapidly, slowly giving way to shrub species, and then to tree 

regeneration following harvesting of timber. Forage is almost nonexistent beneath old-growth 

forests but increases once overstory canopies open. Prescribed fire has also been applied to 

increase forage production. Utilization of 40 percent of the forage growth provides a sustained 

level of livestock production on rangelands in good condition. Forage on high elevation rangelands is grazed from June through late October with continuous yearlong livestock grazing on 

lower elevations.

Oak woodlands Throughout California and 

scattered in western Colorado, Utah, and southwestern New Mexico and 

southeastern Arizona.

Inherently low levels of growth, irregular stem forms, and a lack of markets constrain the intensive management of oak trees for wood production, although trees are cut locally for fuelwood, 

and small poles and posts. Many of the rangelands are fair to poor in condition. Therefore, 

managers often prescribe a utilization level of forage plants that is less than 40 percent to 

sustained production. Selected seeding of preferred species has improved forage production 

on some rangelands.

Pinyon-juniper 

woodlands

Eastern slopes of the 

Sierra Nevada Mountains, 

eastward throughout the 

Great Basin, through the 

Rocky Mountains of Colorado, southward into New 

Mexico and Arizona.

A past management activity has been to control the invasion of Pinyon-Juniper Woodlands 

onto lower elevation grasslands to reduce competition and improve forage production. Cattle 

and native ungulate forage production declines rapidly as the woodlands increase in density 

due to low precipitation and pinyon-juniper competition. Many rangelands are only fair or poor 

in their condition. As a consequence, managers consider utilization of forage plants in excess 

of 40 percent to be detrimental to sustained forage production (Gottfried 1999).

Mesquite-dominated 

ecosystems

Scattered throughout the 

semidesert rangelands 

of the region, along the 

southern boundaries of 

Arizona, New Mexico, 

and western Texas.

Mesquite as an agroforestry resource is a source of fuelwood, poles and posts, and feed for 

ruminants. It also makes excellent charcoal. Small wood-producing (cottage) industries largely 

dependent on mesquite as the raw material have evolved into a number of profitable enterprises in the southwestern United States. Knowledge of effective silvicultural practices is limited, 

however, jeopardizing achieving sustainability of the wood resource (Ffolliott 1999).

ac = acre. ha = hectare.

Box A.1. But is it agroforestry?

Silvopastoral activities and food gathering within forests have 

been long-standing activities in the Southwest, especially on 

Federal lands (Bainbridge 1995). The question arises, however, 

regarding whether all silvopastoral and food-gathering 

activities are agroforestry. By definition, agroforestry must be

intentional, intensive, deliberate, and integrated (Gold et al. 

2000). Although it is easy to see how practices involving the 

introduction of trees into agricultural operations may meet 

this definition, it is less clear for those activities occurring 

on nonagriculturally managed lands. Silvopastoral systems 

have been described in the literature as “a form of structural 

agroforestry in which tree, forage, and animal components all 

share the same hectare of land at the same time” (Sharrow 

1999: 113). Some of these systems, though, lack intentional 

design and/or management for the production of trees, tree 

products, forage, and livestock components (USDA NAC 

2014). Examples of such systems would be livestock grazing 

that occurs on forest land where adequate forage already 

exists or on rangeland where trees are encroaching, which 

would probably reflect most of the grazing operations that 

occur on Federal lands. Likewise, harvesting of foods and 

other nontimber forest products from forested land in the 

Southwest and elsewhere, especially from Federal lands, 

is another gray area in terms of whether these activities are 

actually agroforestry. The question in this case becomes—Is 

the practice wild harvesting or is it forest farming (agroforestry)? 

Again, to be considered forest farming (agroforestry), 

deliberate management of the forested (treed) area to 

enhance the production of these products needs to exist. 

On Federal lands, agencies such as the U.S. Department 

of Agriculture, Forest Service are working to develop forest 

plans that take into account climate change impacts and the 

sustained production of these nontimber forest products, 

especially those that many Native American tribes rely on as 

indigenous foods (see chapter 5).

continued on next page
162 Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions

Box A.1. But is it agroforestry? (continued)

The distinction of whether a practice is agroforestry is not 

an absolute one. Rather, it is one of discerning where on 

the continuum of design and management the practice lies 

and then deciding whether that is enough to qualify it as an 

agroforestry practice.

To complicate the discussion further, situations exist, especially 

on Federal lands, in which management decisions are made 

for a primary purpose(s) other than agricultural production, 

but which can then secondarily provide agricultural benefit. 

In the Southwest, primary goals for thinning forest stands 

are for watershed health services that include improvement 

of timber and tree health, water resource management, and/

or fuel load reduction. Regardless of intent, it also generally 

results in forage production improvement. So the question 

then becomes—Was this benefit to forage growth deliberately 

considered and recognized in the planning process? Further, 

what if the intent is twofold—to increase water resources 

available to downstream agricultural production and to 

increase forage production for grazing?

With our understanding of these practices in the Southwest, 

we do not have the information needed to explicitly state 

the extent of current agroforestry activities nor that of the 

potential of agroforestry in the Southwest. Opportunities are 

emerging that suggest agroforestry may be able to play a larger role in the Southwest as other technologies come on line 

(more efficient and/or recycled water irrigation systems) and 

as the Southwest faces more pressing climate conditions.

California oak woodland management as agroforestry, where goals can include enhanced soil quality and carbon sequestration, generation of annual and longer term incomes from timber products, grazing, and potentially other operations such as mushroom production 

(Dahlgren et al. 2003, Frost et al. 1991). (Photo courtesy of the USDA Natural Resources Conservation Service).
Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions 163

Management of the region’s watersheds to ensure sustainable 

flows of high-quality water to downstream agricultural and 

municipal users in this drought-prone part of the country is 

integral to the sustainability of this region. Climate projections 

of increasing and prolonged drought make this service an 

important consideration when determining management 

strategies and actions for this region.

Threats and Challenges to Agricultural 

Production, Forestry, and Community 

Sustainability

The Southwest has heated up in recent decades, and the period 

since 1950 has been hotter than any comparably long period 

in at least 600 years (Melillo et al. 2014). The 2001-to-2010 

decade was the warmest in the 110-year instrumental record, 

with temperatures nearly 1.1 °C higher than historic averages, 

fewer cold air outbreaks, and more heat waves (Kunkel et al. 

2013). Regional annual average temperatures are projected to 

rise by 1.4 to 3.1 °C by the 2041-to-2070 period (Garfin et al. 

2014). Extreme daytime and nighttime temperatures have been 

shown to accelerate crop ripening and maturity; reduce yields 

from vegetables, fruit trees, and vineyards; cause livestock 

stress; and increase agriculture water consumption (Walthall 

et al. 2012). The freeze-free period throughout the Southwest 

is estimated to increase on average by about a month by 2055, 

with the largest increases (greater than 35 days) occurring in 

the interior of California (Kunkel et al. 2013). It is projected 

that required winter chill periods will fall below the number of 

hours necessary for many of the nut- and fruit-bearing trees of 

California and that yields will decline as a result (Luedeling et 

al. 2011). Under warmer winter temperatures, some existing 

agricultural pests can persist year round, while new pests may 

become established (Garfin et al. 2014). Pollination services by 

managed honey bee colonies are expected to decline under predicted climate change scenarios (Reddy et al. 2013), impacting 

the numerous pollinator-dependent crops in the region.

Long-term and extensive drought is the greatest threat to 

agricultural production and forestry in the Southwest (Garfin et 

al. 2014). To compound this threat, the region is projected to 

transition to a more arid climate (Seager et al. 2007). Drought, 

as expressed in Colorado River flow, is projected to become 

more frequent, more intense, and longer lasting, resulting in 

water deficits heretofore not seen in the instrumental record 

(Garfin et al. 2014). The current drought in California may 

foreshadow what is coming (fig. A.5).

The drought in California is posing community sustainability 

challenges. Current projections are for an unemployment rate 

of 50 percent in farm towns (Marois 2014). This trend threatens 

the viability of small farming communities that are spread 

throughout the agricultural region of the State. It also impacts 

State and national budgets, which are required to deal with 

unemployment. Larger cities can be affected by influxes of 

unemployed people from farming communities.

Numerous threatened and endangered (T&E) species reside in 

the region and likely will experience increasing pressure under 

climate change (Staudinger et al. 2012). Rangeland grazing 

historically has contributed to impacts on T&E species (Flather 

and Joyce 1994). Negative impacts to 22 percent of federally 

listed T&E species have been attributed to livestock grazing 

in Southwest forests (Wilcove et al. 1998). Because of T&E 

species concerns and other environmental issues, public land 

grazing is a contentious issue that will likely escalate under 

climate change, and strategies to reduce impacts will need to be 

implemented (Brown and McDonald 1995).

Agroforestry as an Opportunity To Build 

Resilience

Bainbridge (1995) describes a variety of opportunities for 

agroforestry practices in the Southwest. In this summary, 

we highlight a few. Numerous adaptation strategies exist for 

managing grazing lands under climate change (Joyce et al. 

2013), and managing forested rangeland grazing as silvopastoral agroforestry systems can offer another option for enhancing 

stability and resilience in the agriculture and forestry economies (Bainbridge 1995). The greater diversity of enterprises 

that can be incorporated with the livestock grazing, beginning 

with timber products but extending to nontimber products (e.g., 

mushroom production) (Harper et al. N.d.) and hunting and recreational operations (Standiford and Howitt 1991), can reduce 

risk under variable climate. In addition, this type of operation 

may also provide other ecosystem services and goods, such 

as improved soil health, carbon sequestration, and long-term 

productivity (Dahlgren et al. 2003, Frost et al. 1991).

During the next several decades, many Southwest forests 

will be going through restoration treatments to reduce fuels 

and to manage stands at an appropriate density to withstand 

frequent, low-severity fires. Overstocked forests have led to 

large, high-severity, landscape-level wildfires. The Four Forest 

Restoration Initiative is an example of the type of programs 

that need to be initiated to restore ponderosa pine ecosystems to 

properly functioning conditions (Covington et al. 1997). After 

the restoration thinning treatments, higher densities of grasses 

and forbs will provide significantly greater forage resources 

to support silvopastoral agroforestry. Judicious management 

of animal-stocking levels should be able to provide adequate 

livestock forage, and, in combination with prescribed fire, ensure ecological goals (Laughlin et al. 2006, Moore et al. 2006). 

Because forest harvesting will be episodic after the restoration 

treatments are complete, silvopastoral agroforestry has the 

potential to provide economic resilience for both Federal land 

managers and grazing permittees (Sharrow et al. 2009).
164 Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions

Figure A.5. The State of California recently experienced exceptional drought of prolonged duration, the third most severe on record (Howitt et al. 2014). Stream and irrigation flows to the Central Valley were reduced by 30 percent, and California’s water reservoirs statewide were at 28 percent of total capacity and 49 percent of normal (Howitt et al. 2014). Snowpack levels in the Sierra 

Nevada’s forests were estimated at a 500-year low in 2015 (Belmecheri et al. 2016). Reductions in snowpack and rainfall mirrored 

in depleted water reservoirs impacted the productivity of oak woodlands that sustain silvopastoral agroforestry in California (Asner 

et al. 2016). Surface water losses in California have been offset by unsustainable groundwater pumping at an additional cost of 

$0.5 billion to the State’s agricultural sector (Howitt et al. 2014). (From USDA Drought Monitor, http://droughtmonitor.unl.edu/).
Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions 165

The Southwest also affords several other potential agroforestry 

endeavors tied to nut production. Such endeavors could be 

the deliberate establishment of nut trees, such as pecan, into 

operations or the deliberate management of lands, such as the 

pinyon-juniper rangelands, for pine-nut production, along with 

ongoing grazing activities (Sharashkin and Gold 2004). Tribes 

in the Southwest, as elsewhere, have long depended on foods 

they could harvest from the forests (Bainbridge 1995). Given 

the potential impacts of climate change, such as fire and species 

shifts, using an agroforestry approach for these nontimber 

forest products, even on Federal lands, may need to occur to 

sustain and/or replace production. (See chapter 5 and box A.1.)

Woody species generally used in Southwest agroforestry may 

also be well suited to producing biofeedstock for heat and 

power generation (Kirmse and Fisher 1989). Agroforestry 

could serve as the means for building a viable feedstock 

supply by augmenting the biofeedstock generated from forest 

operations (i.e., fuel load reductions). Use of agroforestry for 

this purpose has some potential in the Southwest, as evidenced 

in California, where short rotation biomass efforts are already 

in progress (Standiford 2014).

Agroforestry also can reduce climate change impacts on 

agricultural production by supporting biological pest control 

and pollination services for high-value crops in the region, 

while creating critical habitat for a diversity of wildlife species. 

(See chapter 2 and box A.2.)

Box A.2. California: buffers, bees, biocontrol, and bucks

One-third of California’s agricultural returns come from 

pollinator-dependent crops (e.g., sunflower, almonds, 

melons, and many other vegetable crops) making pollinators 

key players in California’s agricultural economy. Pollinator 

services needed for this crop production are by managed 

honey bees and also by native bees (Chaplin-Kramer et al. 

2011). Given the continuing dilemma of colony collapse, 

dependence on the honey bee, which is a single species, 

represents a significant vulnerability in the agricultural sector. 

In addition, abundance and numbers of native bee species 

continue to decline as agricultural operations intensify. 

Shifting climate is expected to impact the quality, quantity, 

and timing of habitat components critical to the survival and 

functioning of pollinators.

Hedgerows, windbreaks, and other agroforestry buffer 

practices that are established to provide nonpollinator 

services, such as air-, soil-, and water-quality protection, can 

be used to increase the diversity and abundance of habitat 

features native bees and honey bees need for survival. 

These plantings have also been found to enhance beneficial 

(biocontrol) insects that can help control levels of insect damage to some of these crops in California (Long and Anderson 

2010, Morandin et al. 2014).

With appropriate planning and management, these plantings 

can enhance habitat for both pollinators and biocontrol 

insects by producing the strategic diversity (i.e., a variety of 

flowering plants with overlapping blooming times, a diversity 

of protected and suitable nesting and overwintering sites) 

that will be needed to create resilience under the unpredictable impacts of changing climate (see chapter 2).

Blue blooms of native California lilac and other native shrubs and perennials form part of a 1-mile-long hedgerow in Yolo County, CA. 

Hedgerows have been shown to increase pollination activity from native bees and provide crop protection by harboring beneficial native 

insects over crop pests by a margin of three to one (Morandin et al. 2011). (Photo courtesy of Jessa Cruz, the Xerces Society for Invertebrate Conservation).
166 Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions

Challenges to Agroforestry Adoption

Although agroforestry is often viewed as a potential mitigation 

measure for climate change in both the agricultural and forestry 

sectors (Nair 2012), the practice is also threatened by climate 

change (Pachauri 2012). The big threat that will challenge both 

agroforestry and conventional agriculture in the Southwest far 

beyond any other is drought.

One challenge to silvopastoral agroforestry adoption in the 

Southwest will be T&E species interactions and controversy 

over grazing impacts on the environment. Federal lands that 

make up the bulk of Southwest forests are much more prone 

to this challenge than are private lands. Care will be needed to 

balance stock numbers with productivity potential. Fluctuating 

aridity can cause large changes in forage vegetation productivity. The key to success will be preventing irreversible damage 

to vegetation and site productivity. Because of increasing arid 

conditions, attention will have to be paid to providing adequate 

watering resources for livestock.

The adoption of conventional agroforestry practices on private 

agricultural lands will have the challenge of convincing 

landowners and managers that the economic and ecosystem 

services provided by agroforestry in a drying environment are 

worth the efforts and risk. Because irrigation is an important 

component of agriculture in the Southwest, the issue of 

increased water consumption by tree crops in an environment 

where water is becoming increasingly scarce will remain a 

stumbling block to agroforestry expansion (see chapter 2). On 

the other hand, greater harvesting of recycled water, including 

greywater, may provide an opportunity for use in more 

innovative agroforestry operations, such as plantation pinyon 

pine nut production, in this region.

Key Information Needs

• Create an understanding of tree/forage/grazing interactions 

to develop silvopasture management options that reliably 

provide sustained and profitable operations in the various 

situations in which they can be placed in the Southwest.

• Identify climate change impacts on the dynamics and 

composition of woody and herbaceous plants to determine 

how sustainable agroforestry production systems will be in 

the Southwest under projected conditions. 

• Identify pollinator populations and habitat requirements for 

these species in this region to provide planning and design 

criteria to establish the most effective agroforestry plantings 

for pollinators. 

• Initiate markets and program support for agroforestry 

endeavors to develop sustainable levels of operations for 

producers.

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Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions 169

Great Plains

Gary Bentrup and Michele Schoeneberger

Gary Bentrup is a research landscape planner, U.S. Department of Agriculture (USDA), Forest Service, 

USDA National Agroforestry Center; Michele Schoeneberger is research program lead and soil scientist 

(retired), USDA Forest Service, USDA National Agroforestry Center.

Description of the Region

Extending from Mexico to Canada, the Great Plains Region 

covers the central midsection of the United States and is 

divided into the northern Plains (Montana, Nebraska, North 

Dakota, South Dakota and Wyoming) and the southern Plains 

(Kansas, Oklahoma, and Texas). This large latitudinal range 

leads to some of the coldest and hottest average temperatures in 

the conterminous United States and also to a sharp precipitation 

gradient from east to west (fig. A.6). The region also experiences multiple climate and weather hazards, including floods, 

droughts, severe thunderstorms, rapid temperature fluctuations, 

tornadoes, winter storms, and even hurricanes in the far 

southeast section (Karl et al. 2009).

Agriculture is the dominant land use in the Great Plains, with 

more than 80 percent of the region dedicated to cropland, 

pastureland, and rangeland (Shafer et al. 2014). This sector 

generates a total market value of about $92 billion, approximately equally split between crop and livestock production 

(USDA ERS 2012). Agricultural activities range in the northern 

Plains from crop production, dominated by alfalfa, barley, corn, 

hay, soybeans, and wheat to livestock production centered on 

beef cattle along with some dairy cows, hogs, and sheep. In 

the southern Plains, crop production is centered predominantly 

on wheat along with corn and cotton, and extensive livestock 

production is centered on pastureland or rangelands and intensive production in feedlots. Crop production is a mixture of 82 

percent dryland and 18 percent irrigated cropland, with 34 and 

31 percent of total irrigated cropland in the region occurring in 

Nebraska and Texas, respectively (USDA NRCS 2013). In the 

most arid portions, where irrigation is not available and land is 

not suitable for cultivation, livestock grazing is the predominant operation (Collins et al. 2012).

Figure A.6. The Great Plains Region has a distinct north-south gradient in average temperature patterns (A), with a hotter south 

and colder north. For precipitation (B), the regional gradient runs east-west, with a wetter east and a much drier west. Averages 

shown here for the period 1981 to 2010. (Kunkel et al. 2013).

A B
170 Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions

Life in the Great Plains has always been played out against the 

backdrop of a challenging climate, the massive and extensive 

drought of the 1930s being a poignant example. Increasing 

frequency and intensity of extreme weather events, however, is 

starting to have a greater impact on agriculture and communities within the region. Since 2011, the region has suffered from 

severe droughts with swings to significant flooding in both the 

southern and northern Plains, resulting in agricultural losses in 

the billions of dollars (NOAA 2014). Changes in the overall 

climate are also ushering in new conditions that will require 

Great Plains agriculture to adapt. For instance, the average 

temperature in the Great Plains has already increased roughly 

0.83 °C relative to a 1960s and 1970s baseline (Karl et al. 

2009). Creating more diverse and resilient farming systems will 

help mitigate these challenges.

Both positive and negative impacts are predicted for the Great 

Plains as a result of climate change (Melillo et al. 2014). 

Although a longer growing season and increased levels of 

carbon dioxide (CO2) in the atmosphere may benefit some types 

of crop production, unusual heat waves, extreme droughts, and 

floods may offset those benefits (Walthall et al. 2012). Farm 

diversification and intensification through agroforestry may 

help offset some of the negative effects of climate change. 

Before discussing the agroforestry practices that are relevant 

for the Great Plains, we describe a few of the key threats and 

challenges that Great Plains agriculture faces as a result of 

climate change.

Threats and Challenges to Agricultural 

Production and Community Well-Being

Heat events and droughts are expected to increase in frequency, 

along with higher temperatures (Kunkel et al. 2013). These 

conditions can lead to soil erosion by wind, which is a significant threat to both production and human well-being in the 

region (fig. A.7).

Figure A.7. Dust storm event in southern Lubbock County, 

TX, on June 18, 2009. (Photo by Scott Van Pelt, USDA Agricultural Research Service).

Some of the largest areas of highly erodible soils occur within 

this region (USDA NRCS 2013), with an increasing portion 

of these soils being converted to crops (fig. A.8) (Cox and 

Rundquist 2013). Although best management practices have 

reduced wind erosion during the past several decades, many 

areas are still above the tolerable rate for soil loss, and these 

rates are rising again due to extreme weather events (USDA 

NRCS 2013). In addition to the loss of soil productivity with 

wind erosion, human health and safety are also issues. The 

droughts of 2011 through 2014 have increased blowing dust 

events throughout the Plains, reducing air quality and contributing to road-related accidents and fatalities (Lincoln Journal Star 

2014) and also to asthma and other lung diseases (see the Air 

Quality section in chapter 2).

The duration of droughts and heat waves is expected to 

increase in the southern Plains (Kunkel et al. 2013). These 

changes will impact crop productivity and livestock operations 

in terms of animal heat stress and obtaining affordable feed 

(Ojima et al. 2012). Indications are the northern Plains will 

have higher precipitation and warmer temperatures, creating 

longer growing seasons (Kunkel et al. 2013) that will continue 

to facilitate the northward migration of corn and soybean 

production (Barton and Clark 2014). The northern Plains will 

remain vulnerable to periodic droughts, however, because 

much of the projected increase in precipitation is expected to 

occur in the cooler months, and increasing temperatures will 

result in higher evapotranspiration during the growing season 

(Kunkel et al. 2013). In addition, these same conditions are 

expected to result in a northward spread of insects and weeds 

(Walthall et al. 2012). Increasing heavy precipitation events in 

the northern Plains are expected to worsen flooding and runoff 

events, impacting soil erosion, water quality, and downstream 

communities (Groisman et al. 2004, Kunkel et al. 2013).

Climate projections indicate that competition for the region’s 

declining water resources will continue to intensify, especially 

in areas of irrigated corn production in the Great Plains (Barton 

and Clark 2014). Johnson et al. (1983) predicted this area 

would need to eventually return to a dryland production system 

within 15 to 50 years due to water scarcity. With the continued 

water drawdown occurring in the High Plains aquifer, the 

long-term outlook for irrigated operations remains uncertain 

(Brambila 2014, Sophocleous 2010). Given the future climate 

projections for this area, the need to begin making a transition, 

at least in part, to production systems less dependent on water 

seems inevitable.

Because communities in the Great Plains depend highly on 

farms and ranches, any reductions in agricultural output and 

income from climate change pose a significant threat to rural 

economies and vitality. Rural and tribal communities in the 

region already face challenges because of their remote locations, sparse development, and limited local services, which 
Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions 171

Figure A.8. Between 2008 and 2012, 5.3 million acres of previously uncultivated, highly erodible land were planted with row 

crops. Fully 73 percent of that conversion occurred in 425 hotspot counties identified in this map, with most of the counties being 

within the Great Plains. (From Cox and Rundquist 2013. Copyright Environmental Working Group, http://www.ewg.org. Reprinted 

with permission).

only will be exacerbated by climate extremes (Shafer et al. 

2014). Working-age people are moving to urban areas, leaving 

behind a growing percentage of elderly people and diminished 

economic capacity in rural communities (Ojima et al. 2012). 

Approximately 80 percent of Great Plains counties have a 

higher percentage of older residents than the U.S. average 

(Wilson 2009). Reducing risks to agriculture production will be 

an important step in maintaining economically viable communities, which underlies community well-being.

Agroforestry as an Opportunity To Build 

Resilience

Agroforestry first came into widespread use to deal with 

extreme weather events in the Great Plains during the 1930s. 

To combat one of the largest wind erosion events in the United 

States, the 1930s Dust Bowl, more than 200 million trees and 

shrubs were planted in windbreaks from North Dakota to Texas 

through the Prairie States Forestry Project (Droze 1977) (see 

box 2.1). This region continues to be the largest user of this 

practice because of the preponderance of wind in the region 

(figs. A.9 and A.10). The protective services of windbreaks to 

Figure A.9. Most windbreaks established each year are in the 

Great Plains Region based on linear feet of windbreak. Data 

from 2010 are presented because the proportions remained 

similar across all 4 years. No windbreaks were established 

in Alaska based on these data. (Data [2008 to 2010] derived 

from USDA Natural Resources Conservation Service National 

Practice Summary information).
172 Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions

Figure A.10. Wind is a dominant feature in the Great Plains Region, as illustrated by this map, which shows the predicted mean 

annual wind speeds at a 30-meter height based on model-derived estimates. (Wind resource estimates developed by AWS Truepower, LLC. Map developed by the National Renewable Energy Laboratory).

favorably modify microclimate for crops, livestock, farmsteads, 

and wildlife remain the primary reason for use in the region 

(Anderson 1995, Schaefer and Ball 1995) (see also chapter 2). 

As awareness of water-quality and streambank-stability issues 

in the Great Plains has emerged, interest in the protective 

services of riparian forest buffers has also increased. Table A.4 

summarizes the agroforestry practices that are most relevant to 

the Great Plains Region.

Table A.4. Agroforestry practices that have current or potential 

importance in the Great Plains Region. 

Practice

Relevance 

to Great 

Plains 

subregions

Field windbreaks NGP, SGP

Livestock windbreaks NGP, SGP

Farmstead windbreaks NGP

Living snowfences NGP

Riparian forest buffers NGP, SGP

Silvopasture SGP

Incorporating wildlife into agroforestry practice design NGP, SGP

NGP = northern Great Plains. SGP = southern Great Plains. 

Source: Adapted from Anderson (1995) and Schaefer and Ball (1995).

Windbreaks remain a logical choice for building greater 

resiliency in Great Plains agriculture. Field windbreaks in the 

Great Plains have the potential to increase irrigation/water use 

efficiency and, therefore, crop production in this region with a 

high evapotranspiration demand (Dickey 1988). This function 

of windbreaks could also be instrumental for making the 

transition from irrigated to dryland operations where necessary. 

Modeling efforts using several climate change models for 

Nebraska indicate that windbreaks may aid production during 

key points in the growing cycle for nonirrigated corn operations 

(Easterling et al. 1997). For nearly all levels of climate change, 

dryland corn yields were greater under sheltered than nonsheltered conditions, with the greatest benefit of shelter under 

conditions having the maximum precipitation deficiencies 

and windspeed increases. Modeling results suggested the 

following three climate change-related benefits of windbreaks 

on crop yield compared with open fields: (1) night-time cooling 

of the crop that would counteract daytime temperatures in 

sheltered fields, thereby lengthening the period to maturation 

and allowing for greater grain fill and yields; (2) reduction 

in respiration and increase in net primary productivity due 
Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions 173

to lower night-time temperatures; and/or (3) reduction in the 

number of days plants experience water stress due to reduced 

levels of evapotranspiration.

In the southern Plains, the role of windbreaks may be limited, 

depending on how severe growing conditions become and 

with the resultant shifts in profitability. Early windbreak work 

documented enhanced plant and boll biomass in cotton in 

Texas under sheltered conditions (Barker et al. 1985). Although 

windbreaks have also been demonstrated to benefit wheat 

production and protect soils (Brandle et al. 1984), current use is 

limited. Additional research and technology transfer efforts are 

needed to demonstrate windbreaks’ biophysical and economic 

utility to combat current and projected climate impacts on the 

sustained production of this crop.

In the northern Plains, where snow and winter winds are more 

prevalent, windbreaks can be used to distribute snow across a 

field to replenish crucial soil moisture and to insulate fall crops 

against desiccation by cold, dry winter winds (Scholten 1988). 

Livestock in the Great Plains experience a high level of thermal 

stress at both extremes, impacting overall survival, production, 

and profitability. Windbreaks in the Great Plains can provide 

critical livestock protection during extreme cold/snow events 

and also during heat waves (see the Livestock Protection 

section in chapter 2).

Regarding community well-being, agroforestry plantings in the 

Great Plains—again, predominantly windbreaks and riparian 

forest buffers—may offer valuable services. Projected increases in winter and spring precipitation events in the northern 

Plains and the extreme events being predicted throughout the 

Plains can result in increased urban flooding, as evidenced in 

the Red River Valley (ND Forest Service 2010). Waterbreaks, 

a concept similar to windbreaks but with the primary purpose 

of modifying flooding impacts, could aid in reducing flood 

damage (Wallace et al. 2000). In addition, this practice could 

provide other ecological and economic returns from high-risk 

floodplain agriculture (Schoeneberger et al. 2012). Woody 

riparian vegetation can be effective in providing streambank 

protection during large flood events, such as documented in 

Kansas during the 1993 floods (Geyer et al. 2000). Properly 

located windbreaks can reduce home heating and cooling costs 

by as much as 10 to 40 percent (DeWalle and Heisler 1988). In 

the northern Plains, windbreaks can be used as cost-effective 

living snowfences to keep roads cleared and reduce snow 

removal costs and to also provide greenhouse gas emission 

mitigation and carbon (C) sequestration (Shaw 1988).

Valuation of services from windbreaks and other agroforestry 

practices in the Great Plains regarding on-farm and off-farm 

benefits is limited due to the lack of agroforestry inventory 

in the Great Plains and elsewhere (Perry et al. 2005). The 

Great Plains Initiative (GPI) is developing an approach to 

inventorying nonforest trees, including agroforestry, with 

future use of the method to extend beyond the Plains (Lister 

et al. 2012). Using 2009 GPI data, dollar values estimated for 

the various windbreak services in Nebraska were $9 million in 

annual gross income from field windbreaks based on improved 

crop yields, $24 million from energy savings due to farmstead 

windbreaks and $27 million in energy savings for acreages 

(Josiah 2016). The value of these services under changing 

climate would vary, depending on location in the region. These 

estimates do not include offsite benefits from these systems, 

such as reducing the cost of dealing with windblown soil 

removal and increasing C sequestration, two aspects being 

projected as having great significance under projected climate 

changes in the Plains. Adaptation strategies in the northern 

Plains can include using the beneficial microclimate effects 

of windbreaks on crop growth; on the winter protection of 

livestock, roads, and farmsteads; and on wildlife, as identified 

in chapter 2. The findings from Brandle et al. (1992) indicate 

a targeted windbreak planting program in the Great Plains 

could potentially provide considerable C contributions through 

C sequestration in the woody biomass and through indirect 

C benefits via avoided emissions and fuel savings realized 

through reduced home heating requirements and equipment 

usage in the tree-planted area.

Given the flexibility in designing agroforestry systems, options 

to contribute to production, mitigation, and adaptive services 

are many. For instance, the incorporation of suitable plant 

materials within windbreaks or riparian forest buffers could 

serve as an additional source of biofeedstock for onsite or 

school/community heating systems. In addition, harvesting 

biofeedstock from riparian forest buffers can enhance the nutrient-absorbing capacity of the plants, maintaining water-quality 

functions (Schoeneberger et al. 2012). Center pivot irrigation 

corners may provide areas for additional tree plantings that 

can provide wildlife habitat and C sequestration opportunities. 

The potential to store C in the woody biomass in pivot corners 

in Nebraska was estimated between 13 to 60 teragrams during 

a 40-year period from establishment (NE DNR 2001). These 

materials over time could also be used as biofeedstock for 

local heat or power generation if markets and infrastructure are 

available.

Challenges to Agroforestry Adoption

Although the value of agroforestry in the Great Plains has been 

demonstrated since the 1930s, its adoption in the Great Plains 

has been limited (Anderson 1995, Schaefer and Ball 1995). 

A lack of public understanding, institutional infrastructure, 

and quantitative information is identified as the main obstacle 

(Anderson 1995, Schaefer and Ball 1995). Reasons for lack of 

adoption in this region include—
174 Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions

• High cost of establishment and renovations.

• Difficulties/complexities of Farm Bill cost/share assistance 

programs.

• Lack of compatibility with farm machinery now used in 

larger scale operations.

• Perceptions that plantings are costing rather than benefiting 

operations; these costs includes real and perceived competition for water resources (Rasmussen and Shapiro 1990).

• Reluctance by producers to take on the longer management 

timeframes within a predominantly annual system.

• Limited need to adopt risk-reduction strategies for extreme 

weather events due to multiple-peril crop insurance (Wright 

2014).

• Desire by producers to maximize production when crop 

prices are high.

Future climate variability and uncertainty will likely necessitate 

a shift in Great Plains production from maximization of yields 

per acre to one that can better use renewable resources and sustain production, incomes, natural resources, and communities. 

Agroforestry in the Great Plains has the potential to contribute 

to this end (Brandle et al. 1992, Schoeneberger et al. 2012). 

To increase the adoption of agroforestry in the Great Plains, 

both on-farm and off-farm valuations of services afforded by 

these plantings are needed. A study conducted in the northern 

Plains of Canada indicated windbreaks provided significant 

returns that extended beyond the individual practice and farm 

boundaries (Kulshreshtha and Kort 2009). Additional studies 

like this one will be valuable in providing a broader base of 

considerations in management decisionmaking.

Despite the benefits of windbreaks in the Great Plains, a big 

challenge is to keep these practices in place. The declining 

condition of windbreaks in the region has been identified as 

a significant issue, and many of these degraded windbreaks 

are being removed and not replaced because of recent high 

crop prices (Marttilo-Losure 2013). A nursery responsible for 

supplying many of the windbreak seedlings in the northern 

Great Plains has seen a 70-percent decrease in sales from 2002 

to 2013 (Knutson 2014). Interest in the practice still exists, 

however, and two major windbreak workshops—the Great 

Plains Windbreak Renovation and Innovation Conference and 

the Southern Plains Windbreak Renovation Workshop—were 

held in 2012 and 2013. Continued opportunities for exchange 

of windbreak expertise will be required to modify the design 

and management of windbreaks and other agroforestry practices to address future conditions. One such effort is an ongoing 

Great Plains-wide effort to reevaluate the impact of windbreaks 

on crop yields, given current growing conditions, cultivars, and 

management practices.

Another challenge facing agroforestry use in the Great Plains 

is the availability of suitable plant material. Tree and other 

woody plant species will need to be resilient to the same 

future weather and climate shifts. Trees in the Great Plains 

historically have been exposed to numerous pests, diseases, 

and environmental conditions that hinder planting success, 

reduce their effectiveness, and limit their long-term survival. 

Damage in trees planted in the Prairie States Forestry Program 

was observed most commonly in trees previously stressed by 

drought (Read 1958). Modeling efforts by Guo et al. (2004) 

indicate that tree growth in agroforestry-like plantings may be 

impaired in the region under several climate change scenarios, 

likely affecting the services desired from these plantings. 

Findings from Wyckoff and Bowers (2010) suggest shifts in 

climate along with elevated levels of CO2

 may prompt the 

expansion of species from the eastern forests into the Plains, 

potentially increasing new options for suitable plant material.

The number of tree species historically used for agroforestry 

plantings in the Great Plains is few. Two primary species used 

in agroforestry plantings throughout the region, Scots pine 

(Pinus sylvestris) and green ash (Fraxinus pennsylvanica), 

are no longer recommended because of diseases and pests, 

with the recommendation for black walnut (Juglans nigra) 

also becoming questionable with the emergence of thousand 

cankers disease. Because stress events are expected to increase 

in the Great Plains, a greater diversity of plant materials and 

management strategies for creating resilient agroforestry 

plantings will be required. Although agroforestry alone might 

not create sufficient pressure for the innovation and production 

of suitable plant materials, the need for appropriate materials 

for community forestry, green infrastructure, restoration, and 

agroforestry should collectively create ample demand.

Key Information Needs

• Develop climate-smart design, planning, and management 

guidelines for agroforestry systems to better meet the needs 

and conditions of the Great Plains region.

• Conduct an economic assessment of internal and external 

benefits, from production to natural recourse conservation, 

derived over time from agroforestry practices in the Great 

Plains.

• Identify and produce on a large scale a variety of stress-/

pest-/climate-resilient/resistant plant materials for use in the 

different Great Plains growing zones.
Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions 175

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Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions 177

Midwest

Shibu Jose, Michael Gold, and Diomy Zamora

Shibu Jose is the director of the Center for Agroforestry, School of Natural Resources, University of Missouri; 

Michael Gold is the associate director of the Center for Agroforestry, School of Natural Resources, University of Missouri; Diomy Zamora is an extension professor of forestry, University of Minnesota Extension.

Description of the Region

The Midwest Region encompasses the States of Illinois, 

Indiana, Iowa, Michigan, Minnesota, Missouri, Ohio, and 

Wisconsin and includes about 20 percent of the U.S. population 

(61 million), which primarily lives within its cities. Agriculture 

is the dominant land use in the Midwest, with more than 

two-thirds of the land designated as farmland, and plays a 

major role in the regional and national economy (fig. A.11). 

Midwestern States traditionally are considered to be the Corn 

Belt, because corn (Zea mays) and soybean (Glycine max) 

constitute 85 percent of the crop receipts. Agricultural exports 

from the Midwest accounted for more than $86 billion in 2009, 

which amounted to nearly 87 percent of the national agricultural export. A diversity of production systems, however, ranges 

from corn, oats, soybean, and wheat to fruits, nuts, vegetables, 

and livestock. The Midwest is also home to some of the most 

valuable timber species in the United States that include 

the central hardwood, northern hardwood, and Lake States 

coniferous regions.

The Midwest Region enjoys a continental climate, with warm 

summers and cold winters. The frequency and intensity of 

extreme weather events, such as droughts and floods, have 

increased during the past few decades, threatening agriculture 

in the region (Andresen et al. 2012). The rate of warming has 

also accelerated, resulting in warmer nights and milder winters. 

For example, the average Midwest air temperature increased 

0.11 °F per decade between 1900 and 2010. The average 

temperature increased twice as rapidly (0.22 °F per decade) 

Figure A.11. Corn acres planted for all purposes, by county, 2015. (Map by USDA National Agricultural Statistics Service).
178 Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions

during the past 60 years and four times as rapidly (0.47 °F per 

decade) during the past 30 years compared with the increase 

from 1900 to 2010 (Kunkel et al. 2013). The Midwest has 

also experienced a lengthening of the growing season by 1 to 

2 weeks since 1950 (Robeson 2002, Skaggs and Baker 1985). 

Fig. A.12 shows that the growing season averaged about 155 

days before the 1930s and has been approaching 170 days in 

recent years (Andresen et al. 2012).

Positive and negative impacts are predicted for the Midwest as 

a result of climate change. Although a longer growing season 

and increased levels of carbon dioxide (CO2

) in the atmosphere 

may benefit agriculture, those benefits may be offset by 

the impacts of unusual heat waves, spring freezes, extreme 

droughts, and floods of greater intensity. Farm diversification and 

intensification through agroforestry may help offset some of 

the negative effects of climate change. The following sections 

describe some of the threats and challenges that Midwest 

agriculture faces as a result of climate change and identify 

potential mitigating effects that agroforestry practices provide.

Figure A.12. Length of growing season in the Midwest. The 

red line is a 10-year moving average. (Andresen et al. 2012).

Threats and Challenges to Agricultural 

Production and Other Ecosystem Services

The Midwest is projected to experience a continuing rise in 

average annual temperature (fig. A.13). This rise will lead 

to increased heat stress and associated yield decline in many 

crops, despite the CO2

 fertilization effect. Trees modify site 

microclimate in terms of temperature, water vapor content 

or partial pressure, and wind speed, among other factors. 

Trees can also improve water recharge in the soil and reduce 

Figure A.13. Average annual temperature (red line) across 

the Midwest shows a trend toward increasing temperature. 

The trend (heavy dashed black line), calculated during the 

period 1895 to 2012, is equal to an increase of 1.5 °F. (http://

nca2014.globalchange.gov/report/regions/midwest).

evaporative water loss from exposed soil surfaces. For 

example, windbreaks slow the movement of air and thus, in 

general, reduce evaporative stress. Windbreaks are known to 

improve soil moisture availability, improve the distribution and 

utilization of irrigation water, reduce evapotranspiration, and 

improve crop water use efficiency (Davis and Norman 1988).

Temperature reductions from tree shade can help reduce heat 

stress of crops and animals in agroforestry systems. A study in 

Nebraska showed earlier germination, accelerated growth, and 

increased yields of tomatoes (Lycopersicon esculentum) and 

snap beans (Phaseolus vulgaris) under simulated narrow alleys 

compared with wider alleys (Bagley 1964).

Extreme rainfall events result in more frequent flooding, more 

erosion, declining water quality, and difficulty in crop establishment in the spring. The frequency of heavy precipitation 

events has been increasing in the Midwest in recent decades 

(Changnon and Kunkel 2006). Andresen et al. (2012) showed 

that the number of 24-hour, once-in-5-years storms increased 

about 4 percent per decade since the beginning of the 20th 

century (fig. A.14). This trend of increasing frequency of heavy 

rainfall has exacerbated the intensity and frequency of flooding 

events in the region. Frequent flooding and the resulting loss of 

agricultural production have caused large-scale economic loss 

and hardship in the Midwest in recent years. The introduction 

of trees into agricultural fields as riparian forest buffers or alley 

cropping along the contour as an upland buffer has been shown 

to take up large quantities of water and lower the water table, 

particularly when there is excess water (Anderson et al. 2009). 

Planting fast-growing trees such as poplar (Populus spp.), 

sycamore (Platanus occidentalis), and willow (Salix spp.) in 

combination with shrubs and warm-season grasses in multispecies riparian forest buffers or in alley cropping configurations 

can help lower the water table in marginal land that experiences 
Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions 179

Figure A.14. Temporal pattern of extreme precipitation index 

for occurrence of 24-hour, once in 5-year extreme precipitation 

events in the Midwest. The annual time series and linear trend 

(straight line) are shown in blue. A time series and linear trend 

for the months of May through September are shown in red. 

(Andresen et al. 2012).

frequent flooding or wet conditions (Zaimes et al. 2004, 2008). 

Research also shows that having a 500-foot buffer of trees situated between major rivers and levees can protect levees from 

failure, thus protecting crop fields in floodplains (Allen et al. 

2003). It is well known that properly designed riparian forest 

buffers can reduce surface runoff and sediment loss by as much 

as 90 percent (Udawatta et al. 2005). The same buffers can also 

act as filters to trap, store, and transform agricultural chemicals, 

including pesticides and fertilizers, thereby improving water 

quality in streams and rivers (Lin et al. 2007, Lin et al. 2011).

Stress on the region’s agriculture will likely include larger 

populations of harmful insects. Insect populations are likely 

to increase as a result of warmer winters, increasing their 

winter survival, and higher summer temperatures, increasing 

reproductive rates and favoring multiple generations each 

year. Diversification by introducing trees into monocultured 

croplands will increase the number and abundance of birds and 

beneficial insects that feed on harmful insects. Alley cropping 

is a potentially useful technology for reducing pest problems 

because tree-crop combinations provide greater niche diversity 

and complexity than do annual crops alone (Stamps and Linit 

1998). Studies with pecan (Carya illinoensis), for example, 

have looked at the influence of ground covers on arthropod 

densities in tree-crop systems. Bugg et al. (1991) observed that 

annual legumes and grasses cover crops sustained lady beetles 

(Coleoptera: Coccinellidae) and other arthropods that may 

be useful in the biological control of pests in pecan. Willow 

show promise for supporting biological control of insect pests 

in agricultural systems (Dalin et al. 2011). Stamps and Linit 

(1998) and Stamps et al. (2009) observed similar results in a 

black walnut (Juglans nigra)-based alley cropping system in 

Missouri. In an alley cropping trial with peas (Pisum sativum) 

and four tree species (Juglans, Platanus, Fraxinus, and Prunus

spp.). Peng et al. (1993) found an increase in insect diversity 

and improved natural-enemy abundance compared with 

monocultured peas. Agroforestry systems also have a greater 

diversity of birds compared with monoculture agronomic 

systems and are also likely to provide additional pest reduction 

to adjacent crops (Berges et al. 2010, Gillespie et al. 1995).

Higher summer temperatures will stress livestock, increasing 

costs as livestock productivity decreases and ventilation and 

cooling costs increase. Heat stress has been identified as a 

major constraint to cattle production. At high temperatures, 

evaporative cooling is the principal mechanism for heat 

dissipation in cattle. It is influenced by humidity and wind 

speed and by physiological factors such as respiration rate 

and density and activity of sweat glands. Failure to maintain 

homeostasis at high temperatures may lead to reduced productivity or even death. Providing shade, however, can reduce the 

energy expended for thermoregulation, which, in turn, can lead 

to higher feed conversion and weight gain. For example, in a 

study in Missouri, cattle in a silvopastoral practice gained more 

weight than in open pasture, translating to nearly $50 more per 

cow-calf pair (Kallenbach 2009).

Climate change may threaten forests in the Midwest with 

more frequent droughts and wildfires and larger populations 

of harmful insects. Forest farming and silvopastoral practices 

reduce unwanted understory growth, provide added protection 

from fire, reduce crowding and stress on remaining trees, and 

improve overall forest health. Moser et al. (2008) estimated 

that farmers owned nearly one-half of the 11 million acres 

of all woodlands in three of the Midwestern States (Illinois, 

Indiana, and Iowa). They showed that active management of 

those woodlands increased productivity and biodiversity. Actively managing the woodlands using agroforestry can further 

enhance the value of the forests. For example, periodic thinning 

is essential in maintaining a woodlot under a forest farming or 

silvopastoral practice. Thinning also helps to produce valuable 

sawlogs, and reduce wildfire risks while reducing understory 

invasives and outbreaks of harmful pests.

Degraded air quality due to human-induced emissions and 

increased pollen season duration are projected to be amplified 

with higher temperatures. More than 20 million people in 

the Midwest experience air quality that fails to meet national 

ambient air-quality standards. Traditional farming systems are 

often impacted negatively by high winds. Windbreak systems 

can easily be integrated into existing farm, horticulture, and 

animal production systems to minimize impacts of adverse 
180 Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions

weather caused by climate change. These windbreaks can also 

reduce dust pollution, thereby enhancing air quality.

Specially designed windbreaks and shelterbelts, known as 

vegetative environmental buffers, can improve air quality 

around confined animal feeding operations. Most odor-causing 

chemicals and compounds are carried as volatile organic 

compounds (VOCs) (particulates). These buffers can filter 

airstreams of particulates by removing dust, gas, and microbial 

constituents (Tyndall and Colletti 2007).

Agroforestry Uses—Opportunities and 

Challenges

Early settlers in the Midwest historically practiced slash-andburn agriculture and tended multilayer home gardens. Grazing 

by livestock such as bison, combined with the intentional use 

of fire by Native Americans, was a form of management in 

the oak savanna ecosystem in the region. During the past 30 

years, Federal cost-share programs (e.g., Conservation Reserve 

Program [CRP], Environmental Quality Incentives Program 

[EQIP]) administered by the USDA Natural Resources Conservation Service have resulted in major increases in riparian 

forest buffer establishment in the Midwest Region. A recent 

national assessment revealed that most of the USDA funds 

spent on agroforestry in fiscal years 2011 and 2012, about 

$316 million, enabled landowners across the country to install 

riparian buffers and windbreaks on their land through CRP and 

other USDA conservation programs (USDA 2013).

Research in the Midwest Region has also concentrated on 

selecting plants better adapted to the expected climate change. 

Within in the transition zone from cool-season to warm-season 

forages, preliminary estimates are available for selecting new 

forages with tolerance to moderate or heavy shade that can 

be integrated into alley cropping, silvopastoral, and riparian 

buffer practices (Van Sambeek et al. 2007). Likewise, if crop 

options need to change under a changing climate, decision tools 

exist for selecting new crops with more favorable tree-crop 

interactions (Van Sambeek and Garrett 2004). Other studies 

have concentrated on what cultivars are currently adopted 

and where, to make better decisions as to what cultivars can 

be moved. For example, Casler et al. (2007) examined the 

latitudinal and longitudinal adaption of switchgrass populations. Likewise, understanding genetic variation among nut 

tree cultivars adapted to growing in open conditions rather than 

closed forest conditions will aid in selecting more productive 

mast species for use in alley cropping and silvopastoral 

practices. Results from flood-tolerance screening trials and use 

of large container-grown planting stock will aid in decisions 

regarding what hardwood planting stock to include in bottomland restorations in a region dominated by river systems (Dey 

et al. 2004, Kabrick et al. 2005).

Additional opportunities for agroforestry adoption in the 

Midwest are presented by new, small landowners willing to use 

incentive programs and their own funds to try alternative land 

uses that do not provide immediate financial returns. According 

to the 2012 USDA Census of Agriculture, the number of small- 

(1-9 acres) to medium-sized farms that exist in the Midwest 

represent opportunity for a wide range of agroforestry practices 

(USDA NASS 2014). Hundreds of thousands of acres in the 

Midwest are also under orchard and timber production suitable 

for integrating agronomic and horticultural crops to enhance 

production and utilization of these lands. Alley cropping can be 

used to optimize productivity of the land. The growing demand 

for “nutraceuticals” (supplements designed to optimize nutrient 

benefits) and specialty crops, such as ethnic vegetables, herbs, 

fruits, and nuts, may provide candidate crops for production 

in tree crop alleys. Alley cropping, which is a good option for 

sustainable farming in hilly lands, reduces soil erosion and 

helps diversify regional horticulture production. The emerging 

biobased economy is providing additional opportunities to 

grow fast-growing, short-rotation woody crops and herbaceous 

biomass crops (annuals and perennials) in agroforestry 

configurations in the Midwest. Establishing such mixed-species 

systems in strategic locations in the Mississippi River watershed will help improve water quality and alleviate the hypoxia 

issue in the Gulf of Mexico.

Episodic periods of high commodity row crop prices (e.g., corn 

and soybeans) encourage continued production by farmers, 

sometimes without adequately considering environmental 

implications. During times of high commodity prices, lands 

enrolled under the CRP may be converted back to intensively 

managed row-crop systems when CRP contracts expire. This 

conversion is likely to reestablish the environmental degradation (e.g., loss of soil quality, accelerated erosion causing 

nonpoint source pollution) evident before enrolling. More than 

7.3 million acres of land enrolled in CRP are expiring within 

the next 5 years (USDA-FSA 2012). Of those acres, more than 

one-half are located in the Midwest. Alternative and holistic 

approaches to maintaining these areas in continuous living 

cover systems that support sustainable production and economic opportunities to farmers and that provide conservation 

benefits must be developed using agroforestry (NWF 2012, 

USDA 2013).

With more than 85 percent of the agricultural landscapes 

under corn/soybean rotational systems, riparian and upland 

forest buffers or strips (Tyndall et al. 2013) can be used to 

minimize the environmental impacts of intensive row crops. 

The use of riparian buffers can also meet an expanding set of 

landowners’ and societal objectives. Government cost-share 

programs help to promote the establishment and maintenance 

of buffers through EQIP. State programs, such as the Minnesota Agricultural Water Quality Certification Program, enable 
Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions 181

farmers and agricultural landowners the opportunity to take 

the lead in implementing conservation practices that protect 

our water. Landowners who implement and maintain approved 

farm management practices will be certified and, in turn, 

obtain regulatory certainty for a period of 10 years (Minnesota 

Department of Agriculture 2014).

The Midwest is home to lush hardwood ecosystems, but their 

long-term productivity is threatened due to unsustainable 

woodland grazing (Loeffler et al. 2000). The grazed woodlots 

are often unmanaged for timber, resulting in both low yield 

of forage and reduced timber production. Even though the 

conversion of pastures to planned agroforestry systems 

could have long-term economic benefits for producers, many 

landowners think that it is economically difficult for them to 

make the change. Agroforestry practices can provide landowners with needed income from their land during the 10 to 60 

years or more necessary to sell marketable forest products. As 

an integrated management system, silvopasture can offer better 

woodland management both for economic production and 

environmental benefits and can address these concerns.

The relevance of small-scale farm and forest landowners 

in the Midwest continues to increase as consumer demand 

for food that is locally produced and marketed is gaining 

popularity throughout the United States. Local food markets 

typically involve small-scale farmers and woodland owners 

who sell directly to consumers. A recent study showed that in 

two regions in Missouri (the Old Trails Region near Kansas 

City and the Ozarks Region in the south), local foods created 

approximately 40 to 45 percent more indirect economic activity 

than conventional food sales (Johnson et al. 2014). A growing 

number of smaller acreage landowners practice agroforestry, 

including growing nontimber forest products, such as ginseng 

(Panax sp.), log-grown mushrooms, black cohosh (Actaea 

racemosa), and other cultivated plants under shade. The history 

of wildcrafting and the use of medicinals, especially within 

specific cultural groups, provide additional opportunities for 

development of forest farming in the region (Gold et al. 2004). 

Likewise, the introduction of nut trees, including walnut, 

pecan, and chestnut, into agroforestry practices will not only 

diversity the farmscape but also will enhance the economic 

viability of the farming enterprise.

Agroforestry adoption among landowners remains a challenge 

in the Midwest because of the cost to establish these systems, 

the incompatibility of existing farm equipment, and the long 

lag time before the benefits of these systems can be realized. 

The complexity of the practices, lack of information and 

demonstration sites, and limited extension/outreach personnel 

are also identified as limitations to large-scale adoption of 

agroforestry in the Midwestern landscape.

Key Information Needs

• Interactive maps identifying landowners practicing agroforestry and growing specialty crops.

• Trained professionals with agroforestry certification 

credentials.

• Improved financial information on emerging specialty crops 

coupled with widely tested improved specialty crop cultivars 

available to farmers to reduce risks and ensure profitability.

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184 Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions

Northeast

Sally Claggett, Tracey Coulter, Katrina Krause, and Julie Mawhorter

Sally Claggett is the program coordinator for the Chesapeake Bay Program, U.S. Department of Agriculture

(USDA), Forest Service; Tracey Coulter is the agroforestry coordinator, Pennsylvania Department of Conservation and Natural Resources, Bureau of Forestry; Katrina Krause is a social science analyst, USDA 

Forest Service, Northern Research Station; Julie Mawhorter is the Mid-Atlantic Urban and Community 

Forestry Coordinator, USDA Forest Service. 

Description of the Region

The Northeast Region is composed of 12 States (Connecticut, 

Delaware, Maine, Maryland, Massachusetts, New Hampshire, 

New Jersey, New York, Pennsylvania, Rhode Island, Vermont, 

and West Virginia) and includes 9 of the 10 most densely 

populated States in the country. The Interstate 95 corridor from 

Washington, DC to Boston is a heavily urbanized landscape 

that is mostly at sea level and close to the coast. The Northeast 

climate is diverse—frequent winter storms bring bitter cold and 

frozen precipitation, especially to the north in the New England 

States. Summers are warm and humid, especially to the south 

in the Mid-Atlantic States surrounding the Chesapeake Bay. 

The Northeast has been affected by extreme events such as ice 

storms, floods, droughts, heat waves, hurricanes, and major 

storms in the Atlantic Ocean off the Northeast coast.

The Northeast is naturally forested, but agriculture is vital in 

the region. About 21 percent of land in the 12 States of the 

Northeastern United States is farmland (6 percent of the national total) and 62 percent of the land in the region is classified as 

timberland. The Northeastern United States is home to about 

175,000 farms that collectively produce agricultural commodities worth more than $21 billion per year (USDA NASS 2009). 

The most prevalent commodities in the Northeast are dairy 

products and poultry, split about equally between chicken and 

eggs. About one-half of the field crops grown in the Northeast, 

including pasture, go to animal feed. Horticulture is a relatively 

large portion of total plant production in the Northeast, which 

includes perennial fruits such as apples, pears, blueberries, and 

cranberries.

Farms in the Northeast, on average, are smaller than farms in 

many other parts of the country. Organic production is more 

common in this region than in other regions. Locally grown 

initiatives, such as farmers markets and farm-to-table restaurants, are important to Northeast urban communities.

Urban areas disrupt much of the natural landscape in the region, 

which also is an area of high natural biodiversity—second only 

to the Southeast—and, with the various mountain ranges and 

physiographic provinces, microclimatic variation is extreme. 

The combination of urban areas and natural biodiversity in the 

region indicates a greater importance of the role of agroforestry 

to expand and link natural habitats to support biodiversity and 

adaptation. Farmed lands are a necessary part of landscape 

planning for future climate scenarios. Agroforestry practices in 

the Northeast can also help protect the many communities here 

from flood and fire. Hurricanes Irene, Lee, and Sandy provided 

“teachable moments” by demonstrating the region’s vulnerability to extreme weather events and wide-scale flooding. 

Threats and Challenges to Agricultural 

Production and Community Well-Being

Although some uncertainty exists about the impact of temperature rises on rainfall and storm events, increasing temperatures 

will at least increase the use of water and cause shifts in the 

timing and nature of plant growth and changes in plant species, 

ecosystem composition, pests, and disease dynamics. Between 

1895 and 2011, temperatures in the Northeast increased by 

nearly 2  ̊F (NCA 2014). Projections in the Mid-Atlantic States 

indicate more summer days of extreme heat. More than any 

other region in the United States, the Northeast Region has seen 

a greater increase in extreme precipitation. Between 1958 and 

2010, precipitation during heavy rain events increased by more 

than 70 percent. Due to a rise in sea level, coastal flooding has 

increased approximately 1 foot since 1900. This rate of sea-level 

rise exceeds the global average of approximately 8 inches due 

primarily to land subsidence (NCA 2014).

The following agricultural vulnerabilities are of known concern 

in the Northeast (NCA 2014, USDA Forest Service 2015)—

• Livestock operations could face increased intensity and 

frequency of summer heat stress, which could decrease 

production of dairy and poultry and increase the impact of 

pathogens and parasites. These conditions would likely affect 

livestock health and increase mortality.

• In addition to direct crop damage, increasingly intense 

precipitation events can result in wetter fields that may delay 

planting or harvesting. Field crops are likely to experience 

heat and ozone stress; drought conditions; impacts of water 

inundation on fields; and invasive weed, pest, and pathogen 

outbreaks. 
Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions 185

• Warmer winters could impact apple crops due to earlier 

bloom, causing frost damage; increased summer heat could 

impact fruit set and result in greater susceptibility to fungal 

infections.

• Many varieties of berries require substantial winter chilling 

and may become less viable as warmer winter temperatures 

become more frequent. This trend may cause increased 

freeze damage after plants de-harden or if early bloom 

occurs. Warmer temperatures also likely will intensify 

pest infestations by pests such as the grape berry moth or 

blueberry gall midge.

• Increased summer drought frequency will likely challenge 

Northeast crop producers. Excessive rainfall in the other 

seasons could lead to flooding, delay springtime planting, 

and result in lower crop yields. A longer, hotter growing 

season may benefit some vegetable crops but could also 

intensify weed and pest pressures by pests such as the 

Colorado potato beetle, tomato and potato blight, Stewart’s 

Wilt, kudzu, and Palmer amaranth. 

• Milder winters have affected and can further affect maple 

syrup production. With earlier starts in the sugaring season 

currently experienced in central New England and with the 

potential decline in sugar maple trees as a result of shifts in 

forest species composition, producers may experience shorter 

tapping seasons, lower grade syrup, and reduced maple 

syrup production (Rustad et al. 2012, Skinner et al. 2010).

Impacts to community well-being are as follows—

• Sea level rise, saltwater intrusion, and flooding will 

compromise infrastructure and will increased the need for 

emergency response actions. 

• Erosion from heavy rains and, conversely, erosion from drier 

conditions can adversely affect commercially important 

aquatic fish and shellfish habitat, as can agricultural pollutants. With additional precipitation, fertilizer applications 

could increasingly end up in waterways, greatly exacerbating 

dead zones in our bays and estuaries. Additional sediment 

in runoff can also be devastating because it greatly alters 

underwater habitat and can block primary production and 

sunlight energy. 

• Many weeds, pests, and fungi thrive under warmer temperatures, wetter climates, and increased carbon dioxide (CO2

) 

levels. Many weeds and vines respond better than desirable 

vegetation to increasing CO2 concentrations.

• Because each species has a unique biological response 

to climate change, disruptions of important species 

interactions—especially with plants and pollinators—can 

be expected. This shift in range and plant lifecycle can 

have negative effects culturally on traditional forest food 

gathering by Native American communities—such as the 

Wabanaki society’s use of berries in the Northeast (NCA 

2014).

Agroforestry as an Opportunity To Build 

Resilience

Agroforestry, as a professional term and suite of practices, has 

been gaining attention among partners in the Northeast Region 

during the past 5 or more years, though some agroforestry-related practices have been in use for decades. The ingenuity and 

flexibility of agroforestry practices and the potential for the 

long term would be a welcome addition to many farms in the 

region. On a larger landscape scale, agroforestry could play an 

important community role by protecting communities, reducing 

pollutants, storing carbon (C), adding green jobs, and providing 

linkages and corridors for ecosystem functions.

In summary, agroforestry can help manage the uncertainties 

and complexities of climate change on multiple fronts by—

• Reducing the impacts of extreme and shifting weather 

patterns on agricultural production.

• Expanding and linking natural habitats to support biodiversity adaptation.

• Protecting communities from flood and fire.

• Trapping sediments and nutrients before they wash into 

sensitive aquatic habitats. 

• Reducing C impacts through the production of lower 

emitting biofuel energy and building materials (wood) that 

store C.

• Providing economic benefits and incentivizing conservation 

practices by making them more affordable, or providing 

cost-effective alternatives to traditional approaches.

As part of the development of the Chesapeake Forest 

Restoration Strategy (USDA Forest Service 2012), a regional 

Chesapeake Agroforestry Team was formed in 2011, with representatives from the U.S. Department of Agriculture (USDA) 

(Natural Resources Conservation Service [NRCS] and Forest 

Service), State forestry agencies, and universities. An expanded 

version of this team held a 2-day meeting in May 2014 to 

identify common agroforestry priorities across the partners, and 

the group is now developing a plan and structure for ongoing 

collaboration and network building. Additional examples of 

agroforestry collaborations are woven into the summary of 

specific agroforestry practices in the following sections.
186 Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions

Riparian Forest Buffers

Riparian forest buffers have been the primary agroforestry 

practice implemented in the Northeast Region to improve water 

quality, wildlife habitat, and farm sustainability. For example, 

since 1996, States in the Chesapeake Bay watershed have set 

policy targets for restoring riparian forest buffers on farmland 

and have made great strides in implementing these goals 

through landowner cost-share programs, such as the USDA 

Conservation Reserve Enhancement Program. More than 

7,400 miles of riparian forest buffers have been restored in the 

watershed since the late 1990s (USDA Forest Service 2012). 

Despite this progress, implementation of riparian forest buffers 

has dropped significantly during the past 5 years, prompting 

renewed partnership efforts to promote the practice. As part of 

the Chesapeake Bay Executive Order strategy, USDA supported a 2014 leadership summit and State task force process to 

address key barriers and identify new strategies for accelerating 

riparian forest buffer restoration in the future.

With climate change impacts, riparian forest buffers and other 

types of green infrastructure will be needed more than ever 

to help moderate the effects of intensified storms, flooding, 

and related hydrologic regime changes. Farmers benefit from 

the practice by putting a relatively small area of vulnerable, 

marginally productive land into a natural buffer that absorbs 

flooding impacts and reduces polluted runoff, while focusing 

resources on productive farmland outside the floodplain/

riparian zone.

Riparian forest buffers—also a key tool in headwater streams 

of the Northeast—help protect sensitive cold-water aquatic 

species from increases in water temperatures resulting from 

climate change. For example, partners in the Eastern Brook 

Trout Joint Venture conducted sophisticated climate/habitat 

analyses and identified riparian forest buffer restoration as 

a key strategy to retain and restore brook trout populations 

(Trumbo et al. 2010).

Riparian forest buffers restore to trees those areas that may 

have been in row crop agriculture, pastureland, or other land 

uses with limited ability to store C. Tree cover increases C 

storage in both long-lived woody biomass and stable, high-C 

forest soils. Increased C storage may eventually reverse the 

effects of climate change.

Forest Farming

Forest farming—or more broadly, the sustainable management 

of nontimber forest products—is another important agroforestry practice in the Northeast Region where most of the land 

is forested. A key challenge facing many forest landowners 

is having the economic resources to keep the forest land base 

sustainably managed and intact amidst development pressures. 

Forest farming can provide supplemental income to support 

forest landowners, including farmers who own woodlots. 

Sustainable management of nontimber forest products, such as 

maple syrup, mushrooms, and medicinal plants, can provide 

diversified income streams to buffer losses due to erratic 

weather patterns, new disease and insect infestations, and other 

anticipated effects of a changing climate.

Most maple syrup production in the United States (87 percent) 

takes place in seven Northeast States—Connecticut, Maine, 

Massachusetts, New Hampshire, New York, Pennsylvania, and 

Vermont—with Vermont comprising 41 percent of the annual 

U.S. production (USDA NASS 2015). Researchers at Cornell 

University who examined the potential impact of climate 

change on the maple syrup industry found that the number of 

sap flow days may not change in the Northeast, but the timing 

of peak production will shift earlier (Skinner et al. 2010). The 

findings suggest that, by adapting to an earlier tapping season, 

maple syrup producers in Vermont and other Northern States 

may be able to sustain their livelihoods for the next 100 years, 

but in States farther south, such as Pennsylvania, overall 

production may be reduced sooner.

Edible mushrooms are another forest farming product of 

interest in the region. Recent work by Cornell, the University 

of Vermont, and Chatham University in the Northeast Region 

resulted in the Temperate Forest Mushroom Growers Network, 

which provides growers with resources for the successful 

cultivation and marketing of log- and forest-grown mushrooms, 

including shiitake, oyster, lion’s mane, and stropharia. In 

2012, the three institutions initiated an on-farm research trial 

in which 25 growers inoculated 100 shiitake logs and kept data 

on costs, revenue, labor, and other factors. Researchers found 

that growers were able to begin making a profit in year 2 and 

projected that a small 500-log operation could gross $9,000 

during a 5-year period (Cornell University 2015).

Although some edible and medicinal plants such as American 

ginseng, ramps (wild leeks), goldenseal, and fiddleheads are 

native and occur naturally in some woodlands, these plants are 

threatened by market pressures that can fuel overharvesting and 

depletion of wild populations. Forest farming can help mitigate 

pressure on wild populations of these species. A third-party 

forest-grown verification program was recently launched in 

Pennsylvania to verify woods-grown species are sustainably 

grown or managed. This program, managed by Pennsylvania 

Certified Organic and developed in partnership with Pennsylvania State University researchers and the Pennsylvania 

Department of Conservation and Natural Resources, Bureau of 

Forestry, addresses market demand for ethically and sustainably harvested native edible and medicinal plants.

Additional information and resources regarding forest farming 

are available at the following Web sites developed by partners 

in the region.
Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions 187

• The How, When, and Why of Forest Farming Resource 

Center (Cornell University): http://hwwff.cce.cornell.edu.

• eXtension Forest Farming (Virginia Polytechnic Institute and 

State University and partners): http://articles.extension.org/

forest_farming.

Silvopasture

Silvopasture is an agroforestry practice that, although relatively 

new to the Northeast Region, is gaining in interest among 

natural resource professionals and landowners. Integration of 

trees into existing pasture provides shelter and shade to protect 

animals from temperature extremes and winter storms that 

may intensify with climate change. Carbon is sequestered in 

long-lived tree biomass. Practitioners are also experimenting 

with using intensively managed, short-rotation, fenced grazing 

systems in existing forests through a combination of prescribed 

thinning and enhancing understory forage. These systems must 

be carefully planned and managed to ensure that forest health 

will be improved through the silvopasture system by managing 

invasive understory plants and establishing diverse understory 

vegetation to improve soil health and reduce erosion. Ample 

training and technical assistance for practitioners are needed to 

clarify the silvopasture practice and ensure proper techniques 

are in place to benefit both the grazing animals and the 

condition of the forest.

A regional Web site and networking forum for silvopasture 

has been created by Cornell University: http://silvopasture.

ning.com/. Additional webinars, videos, and other documents 

relevant to silvopasture in the Northeast have been archived at 

http://www.forestconnect.info.

Windbreaks

Windbreaks are a practice that has been used historically in 

the Northeast Region, although less frequently than in other 

regions, such as the Midwest. A modified application of 

windbreaks that has been growing in interest in the Chesapeake 

Bay region is the use of tree windbreaks—or “vegetative 

environmental buffers”—around animal operations such as 

poultry houses. These buffers filter air pollutants and odors that 

are emitted through the fans of these animal facilities, while 

also providing a visual screen for the facility, protecting it from 

wind and temperature extremes and sequestering C. In areas 

with heavy snow accumulations, living snow fence windbreaks 

can keep snow off roadways and can save energy by reducing 

snow removal needs.

Other agroforestry applications such as alley cropping have 

not been widely used in the Northeast but are included in 

agroforestry trainings and may find increased interest in the 

years ahead.

Challenges to Agroforestry Adoption

Agroforestry is still relatively a new term in the Northeast Region. Many practitioners cite lack of awareness of the practices 

and limited access to technical assistance as a key challenge 

to adoption. In the course of history, not much integration has 

occurred among the agricultural and forestry professionals 

who serve landowners. Furthermore, as noted, there are more, 

smaller farms in the Northeast so more landowners to reach.

The region offers niche agroforestry opportunities that may 

be unique from farm to farm requiring even more knowledge, 

research, and technical assistance to demonstrate the tangible 

benefits of adoption. As is often needed for adoption of new 

practices and technologies, real life examples (e.g., demonstration sites) and peer-to-peer networks are important for 

spreading the awareness and use of agroforestry practices. The 

Chesapeake Agroforestry Team, referenced above, identified a 

number of recommended actions to help overcome barriers and 

promote expanded use of agroforestry in the region.

Chesapeake Forest Restoration Strategy: 

Recommended Actions for Agroforestry

• Work with NRCS State Technical Committees in the Chesapeake Bay watershed to promote agroforestry practices 

through Farm Bill programs. 

• Deliver train-the-trainer workshops that target resource 

professionals in the watershed as a first step toward reaching 

watershed landowners. Subsequent workshops can introduce 

agroforestry practices to landowners. 

• Establish agroforestry demonstration areas by finding early 

adopters with working farms and forests so that others can 

see the conservation and economic benefits of agroforestry 

practices. Pursue USDA Conservation Innovation Grants and 

other funding sources to establish these sites. 

• Work with staffs of the NRCS Ecological Sciences Division 

in the Chesapeake Bay watershed to get the five main 

agroforestry practices included in the Field Office Technical 

Guide and Farm Bill programs. 

• Explore a bay branding campaign for agroforestry products 

similar to Edible Chesapeake but focused specifically on 

foods and products developed from businesses committed 

to sustaining working forests within the Chesapeake Bay 

watershed. 

• Design and implement agroforestry research projects 

to ensure stakeholders have access to cutting-edge and 

regionally relevant science. 

• Expand application of agroforestry practices and innovations 

to small-scale landscapes, including urban settings.
188 Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions

Key Information Needs

• Conduct additional field research to better quantify the 

environmental, social, and economic benefits of agroforestry 

practices in mitigating specific climate change impacts in the 

Northeast.

• Increase the limited data that are available on the geographic 

extent of agroforestry practice implementation in the region 

to assist current and potential agroforestry practitioners with 

appropriate climate change adaptation strategies.

• Conduct further analysis of climate-related changes in 

vegetation and wildlife species composition/ranges affecting 

the Northeast to inform agroforestry practice guidance in the 

region.

Literature Cited

Cornell University. 2015. Mushrooms turning a profit for forest 

farmers in the Northeast. Cornell Small Farms Program Quarterly. Winter 2015. http://smallfarms.cornell.edu/2015/01/12/

mushrooms/. (18 October 2016).

National Climate Assessment (NCA). 2014. Climate change 

impacts in the United States: the Third National Climate 

Assessment (Northeast chapter). Washington, DC: U.S. Global 

Change Research Program. 25 p. http://nca2014.globalchange.

gov/report/regions/northeast. (18 October 2016).

Rustad, L.; Campbell, J.; Dukes, J.S. [et al.]. 2012. Changing 

climate, changing forests: the impacts of climate change on 

forests of the Northeastern United States and eastern Canada. 

Gen. Tech. Rep. NRS-99. Newtown Square, PA: U.S. 

Department of Agriculture, Forest Service, Northern Research 

Station. 48 p. http://www.treesearch.fs.fed.us/pubs/41165. 

(18 October 2016).

Skinner, C.; DeGaetano, A.; Chabot, B. 2010. Implications of 

twenty-first century climate change on Northeastern United 

States maple syrup production: impacts and adaptations. 

Climatic Change. 100(3-4): 685–702. http://link.springer.com/

article/10.1007%2Fs10584-009-9685-0. (18 October 2016).

Trumbo, B.; Hudy, M.; Smith, E. [et al.]. 2010. Sensitivity and 

vulnerability of brook trout populations to climate change. In: 

Carline, R.F.; LoSapio, C., eds. Proceedings, 10th Annual 

Wild Trout Symposium, West Yellowstone, MT. Bozeman, MT: 

Joseph Urbani & Associates: 62–68.

U.S. Department of Agriculture (USDA), Forest Service. 2012. 

Chesapeake Forest Restoration Strategy. Newtown, PA: 

U.S. Department of Agriculture, Forest Service, Northeastern 

Area State and Private Forestry. 35 p. http://executiveorder.

chesapeakebay.net/chesapeakeforestrestorationstrategy.pdf. 

(20 October 2016).

U.S. Department of Agriculture (USDA), Forest Service. 2015. 

Northeast Regional Climate Hub Assessment of Climate 

Change Vulnerability and Adaptation and Mitigation Strategies. 

Durham, NH: U.S. Department of Agriculture, Forest Service, 

Northern Research Station: 65 p. http://climatehubs.oce.usda.

gov/sites/default/files/Northeast%20Regional%20Hub%20

Vulnerability%20Assessment%20Final.pdf. (20 October 2016).

U.S. Department of Agriculture, National Agricultural Statistics 

Service (USDA NASS). 2009. 2007 Census of agriculture. 

http://www.agcensus.usda.gov/Publications/2007/. (20 October 

2016).

U.S. Department of Agriculture, National Agricultural Statistics 

Service (USDA NASS). 2015. Northeast maple syrup production. Washington, DC: U.S. Department of Agriculture, National 

Agricultural Statistics Service. 4 p. http://www.nass.usda.

gov/Statistics_by_State/New_England_includes/Publications/

Crop_Production/NE%20Maple%20Syrup%20Production.pdf. 

(20 October 2016).
Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions 189

Southeast and Caribbean

Sarah Workman, Becky Barlow, and John Fike

Sarah Workman is the associate director of the Highlands Biological Station, University of North Carolina; 

Becky Barlow is an associate professor, School of Forestry and Wildlife Sciences, Auburn University; John 

Fike is an associate professor, College of Agriculture and Life Sciences, Virginia Tech.

Description of the Region

Cropland and pastureland occupy significant portions of land 

area in the Southeastern United States. Forests occupy from 50 

to 69 percent of the land within each State in the region 

(fig. A.15). All of these land uses provide significant productivity and income. The Southeast encompasses physiographic 

provinces, or ecoregions (Wear and Greis 2012), that have 

unique climate, fire history, and composition of vegetation. 

From the physiographic province of the Appalachian Mountains 

Figure A.15. Acres of land-use categories of the 11 Southeastern States. (Map and table prepared by William M. Christie, Eastern 

Forest Environmental Threat Assessment Center, USDA Forest Service, Southern Research Station, Asheville, NC).
190 Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions

to the alluvial plains of the Mississippi River Basin, within 

deciduous forests of Kentucky and Tennessee and the Interior 

Highlands of the Ozarks, to the Piedmont, Flatwoods, and 

Coastal Plains, a large portion of the land area is appropriate 

for implementing several types of agroforestry, integrating 

either crops or livestock, or both, with trees and woody 

crops. All these Southeastern ecoregions have land area 

capable of supporting agroforestry as a tool for climate-smart 

agriculture to meet priority elements of the U.S. Department 

of Agriculture (USDA) Climate Change Science Plan (USDA 

2010a). Diversified landscapes using agroforestry practices in 

the Southeast can help enhance rural prosperity; restore and 

conserve the Nation’s forests, farms, ranches, and grasslands; 

and help protect and enhance America’s water resource—all 

elements of strategic goals stated in the plan.

As part of the Lesser Antillean archipelago, the U.S. Caribbean 

islands consist primarily of Puerto Rico and the U.S. Virgin 

Islands, along with disputed Navassa Island, Bajo Nuevo Bank, 

and Serranilla Bank. Puerto Rico is the largest island of a group 

of cays and islands that includes Mona, Monito, and Desecheo 

to the west and Culebra and Vieques to the east. Of the island 

of Puerto Rico, 53 percent is mountainous (three ranges), with 

nearly 12 percent of the landscape in ridges, 25 percent in 

plains, and 20 percent in hills. Dry climatic conditions prevail 

on nearly 30 percent of the island and, of the 57 landscape units 

of the islands of Puerto Rico, the most abundant landforms are 

moist and wet slopes, primarily on volcanic soils (Gould et al. 

2008, Martinuzzi et al. 2007, PR DNER 2009). Six subtropical 

Holdridge life zones are on the island (Ewel and Witmore 

1973). The island also has diverse terrestrial, wetland, coastal, 

and marine ecosystems and also agroforest and urban systems 

(Miller and Lugo 2009).

The U.S. Virgin Islands has three large islands—St. Croix, St. 

John, and St. Thomas—and includes nearby Water Island along 

with 68 smaller islands and cays. The topography is characterized by central mountain ranges and small coastal plains. The 

uplands are rocky, rugged slopes; e.g., 50 percent of St. Croix’s 

land area contains slopes of 25 to 35 percent. Natural influences 

such as landslides, hurricanes and tropical storms, and fire are 

key to shaping the environment and the marine and terrestrial 

communities of the islands (Chakroff 2010).

From the viewpoint of suitability, the Caribbean islands provide a diversity of tropical species and a variety of options for 

agroforestry-based land management. Puerto Rico consists of 

49 percent forest, 33 percent agriculture/pasture, and 14 percent 

developed land. Forest cover is approximately 90 percent on St. 

John (two-thirds national park), 70 percent on St. Thomas, and 

55 percent on St. Croix (fig. A.16). Loss of forested landscapes 

to development is perhaps the greatest land-use pressure for 

Puerto Rico; this places critical stress on watersheds and results 

in a fragmented and increasingly urbanized landscape. Also, 

land use outside developed zones is perhaps best viewed in 

terms of the nature of woody plant cover and whether animals 

are excluded or allowed access. Both Puerto Rico and the U.S. 

Virgin Islands are experiencing a trend toward an increase in 

woody cover with the loss of agricultural land and pastureland 

(Brandeis and Turner 2013a, 2013b; Brandeis et al. 2009). 

With informed management, this cover could be suitable for 

return to production or conservation use and less prone to the 

establishment of invasive plants.

Agroforestry practices are viable for both larger acreages and 

for small land holdings for mitigation and adaptation to climate 

change and resilience under climate variability in the Southeast 

United States-Caribbean. The economics of risk and value of 

diversified systems bode well for production in the region. 

Riparian forest buffers and conservation buffers with trees are 

the most widely used practices across the Southeast (Lowrance 

and Sheridan 2005, Trozzo et al. 2014b, Twilley et al. 2001). 

Buffers may be more popular, because they typically can meet 

objectives of the landowner and help maintain environmental 

health and ecosystem services without active management. 

More interactive and intensified practices, such as energy, food, 

fiber, floral, or medicinal crop production, could be implemented in many of these buffer zones, increasing their overall utility 

and productivity.

The diversity of farms and forest tracts in the region offer many 

opportunities to integrate trees with crop or pasture systems. 

Such systems would benefit many of these lands beyond their 

value for addressing climate change. Sloping lands of the 

Interior Highlands, the Blue Ridge Plateau, and the Caribbean, 

for example, are good candidates for integrating contoured 

swale practices with silvopasture or alley cropping, using nut, 

fruit, fodder, or timber trees to better harvest water and reduce 

erosion (fig. A.17) (Hill 2010, Smith 1929).

In a similar way, forest farming is possible on extensive areas 

of forest and woodland, and people of the southern mountains 

have a long tradition of harvesting and, more recently, of 

cultivating nontimber forest products (NTFPs) (Chamberlain 

et al. 2009, Persons and Davis 2007). Two-strata or multistrata 

land management options—whether with crop and timber 

trees or NTFPs—can offset seasonal risks associated with 

monocultural production systems and buffer the suite of effects 

driven by a shifting climate. That tree crops provide protective 

functions (e.g., soil and water conservation) especially on 

marginal lands or steeper slopes, is becoming more widely 

recognized (Delgado et al. 2011). These diversified agroforestry systems can offer reduced risk and greater economic stability 

under climate variability with both short- and long-term income 

sources (CIER 2008, Cubbage et al. 2012). Recent census data 

confirm producers are identifying and using these practices, 

although current adoption rates are low (table A.5).
Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions 191

Figure A.16. Acres of land-use categories of the Caribbean islands—U.S. territories. (Map and table prepared by William M. Christie, 

Eastern Forest Environmental Threat Assessment Center, USDA Forest Service, Southern Research Station, Asheville, NC).
192 Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions

Table A.5. Selected agroforestry practices, 2012 Census of 

Agriculture—State Data. 

State

Farms practicing 

alley cropping 

or silvopasture 

(farms in State)

Percent of 

farms practicing 

agroforestry

Alabama 119 (43,233) 0.28 

Arkansas 47 (45,071) 0.10

Florida 137 (47,740) 0.29

Georgia 99 (42,257) 0.23

Kentucky 96 (77,064) 0.13

Louisiana 37 (28,093) 0.13

Mississippi 65 (38,076) 0.17

North Carolina 119 (50,218) 0.24

South Carolina 51 (25,266) 0.20

Tennessee 51 (68,050) 0.08

Virginia 74 (46,030) 0.16

Total farms 895 (511,098) 0.18

Nationwide, 2,725 farms report using agroforestry practices. Thus, one-third of 

the reporting farms nationwide which use these practices are in the Southeast 

United States.

Source: Adapted from Table 43; USDA National Agricultural Statistics Service.

Along with agroforestry’s potential in agricultural and forested 

systems, incorporating agroforestry practices may provide 

many benefits on lands that could be classified as mixed land 

cover (after Riitters et al. 2000). These benefits would be at 

the interfaces of agricultural lands with forests or with either 

of these cover types with urbanized areas. At these interfaces, 

agroforestry practices hold the potential to help buffer against 

the effects of forest fragmentation, to provide or mimic natural 

corridors for species movement (wildlife) or maintenance (biodiversity), and to increase options for provision of ecosystem 

services in these dynamic land-use landscapes (e.g., Douglas 

and Jennings 2014, Morgan and Zimmerman 2014).

Threats and Challenges to Agricultural 

Production and Other Ecosystem Services

Land-use change (e.g., due to urbanization and market forces), 

climate change, and environmental policies affecting land-use 

choices are the largest potential challenges or uncertainties facing agricultural and forested landscapes in the Southeast (e.g., 

Keyser et al. 2014). Under current climate change scenarios, 

the Southeast faces increasing temperatures and frequency of 

extreme weather events, reduced precipitation, and land area 

losses due to rising sea levels. Increased disturbances such as 

drought (Pederson et al. 2012, Seager et al. 2009, Sun et al. 

2013), insect infestations (Brandle et al. 2004, Doblas-Miranda 

et al. 2014, Poch and Simonetti 2013), hurricanes (Mitchum 

2011, Philpott et al. 2008), and fire (Liu et al. 2014, Mitchell 

et al. 2014, Stanturf and Goodrick 2012) may also occur as 

a consequence of climate change (Vose et al. 2012). These 

responses are likely to be magnified by the changes in land use 

and cover, which are occurring at some of the most rapid rates 

nationwide.

The main threats to the production and supply of ecosystem 

services in Puerto Rico include lack of resource management, 

lack of incentives, lack of valuation of forested land, threats 

from invasive species and nonnative grasses, wildfire, and climate change. In the U.S. Virgin Islands, primary threats include 

lack of effective forest management strategies, lax enforcement 

of existing statutes, and too few technical professionals with 

adaptation/mitigation knowledge. The Caribbean archipelago 

is a global biodiversity hotspot, and species manipulation 

and unregulated species introductions are threats to local 

ecological systems (vegetation, wildlife, and hydrological 

Figure A.17. Swale system on a hillslope, St. Croix, U.S. Virgin Islands, before (A) and after (B) installation of contour tree rows 

and horticultural crop. The hedgerows are planted with fruit trees and fodder trees that are periodically coppiced for leaf material 

to serve as animal feed. The crop fields are rotated seasonally and annually to diversify and manage production. Soil and water 

conservation are a valued ecosystem service on these slopes. (Photos by Nate Olive, Ridge to Reef Farm).

A B
Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions 193

processes). Despite these challenges, climate is the overarching 

influence on forest species composition when recovering from 

deforestation; all other factors are secondary to the influence 

of climate (Brandeis and Turner 2013a, 2013b). Based on the 

2014 National Climate Assessment for the U.S. Southeast and 

the Caribbean (Carter et al. 2014), the region is exceptionally 

vulnerable to sea level rise, hurricanes, extreme heat events, 

and decreased water availability. Freshwater availability is 

already an issue in the region (CCCCC 2009).

On Caribbean islands, businesses, ports, and homes ring the 

coast and are extremely vulnerable to small rises in sea level. 

With 56 percent of the population living in coastal municipalities, Puerto Rico has one of the highest population densities 

in the world. As a result of current sea-level rise, the coastline 

of Puerto Rico around Rincón is being eroded at a rate of 3.3 

feet per year (Carter et al. 2014). Temperatures for Puerto 

Rico under climate change with global warming are projected 

to increase 2 °F to 5 °F by the end of the century (Carter et al. 

2014). The trend exhibited in the Caribbean since the 1950s is 

of increasing numbers of very warm days and nights, with daytime maximum temperatures rising above 90 °F and nighttime 

temperatures remaining above 75 °F. Increasing temperatures 

contribute to increased fire frequency, intensity, and size.

Also, since the early 1980s, the number of Category 4 and 5 

hurricanes in the Atlantic basin has distinctly increased (Carter 

et al. 2014). Ocean warming could support species shifts, 

growth rate, migrations, and invasive species. Droughts are 

one of the most frequent climate hazards in the Caribbean, 

resulting in economic losses. Precipitation trends in the region 

are unclear, with some higher and some lower average rainfall 

areas noted. Most models show future decreases in precipitation are likely, with a few areas showing increases. Caribbean 

islands already have a high human and livestock health burden 

from climate-sensitive disease. In addition, either because of 

cyclical changes or climate change, more Saharan dust is being 

carried into the region by prevailing winds from Africa.

Agroforestry practices can play a key role in mitigating these 

threats by improving diversity, modifying microclimate to 

maintain production, and enhancing resilience. Although 

recognizing and monetizing the value of ecosystem services 

can be a key challenge, doing so has potential as a mechanism 

for furthering agroforestry implementation, because the value 

of these services may be worth more than the agricultural 

and forest products derived from agroforestry systems (e.g., 

Alam et al. 2014). Most managers perceive their cropland or 

forested land as most valuable when managed with traditional 

production practices. For this audience, greater government 

investments via cost-share payments may be needed to drive 

the adoption of agroforestry practices to levels that meet desired environmental outcomes under current market conditions 

(Martinuzzi et al. 2014, Stainback et al. 2004). Such support 

may be less important, however, for newer landowners and 

beginning farmers who have goals beyond production outcomes, and these systems may foster greater cross-generational 

ties if they provide ways to support intergenerational transfer. 

Although agroforestry practices offer opportunities to meet the 

challenges of growing global demand for natural resources, 

adaptation measures must go beyond technical solutions around 

single components; they must address human-institutional 

dimensions and the social and economic consequences of 

climate change (Seppälä et al. 2009), especially in support of 

poor and forest-dependent communities.

Policies to mitigate climate change likely will have both direct 

and indirect impacts on production systems of the region. For 

example, the Southeast is predicted to supply about one-half 

the biomass for U.S. bioenergy systems in the future (USDA 

2010b). In this scenario, agroforestry practices could help meet 

demands for fuel and fiber, but policies driven strictly to bioenergy feedstock production may run counter to more integrated, 

agroforestry system development. Many private landowners do 

not actively manage their lands, and only some understand the 

connections between their lands and land use and the broader 

ecosystem. Thus, reaching new audiences of landowners with 

effective outreach (e.g., through trusted contacts) and partnering with diverse stakeholder groups for education and incentive 

programs will be critical components in meeting the demands 

for products and ecosystem services from these lands.

Agroforestry as an Opportunity To Build 

Resilience

In the Caribbean, agricultural lands were being abandoned 

by the mid-1800s due to the crash of the sugar market, 

emancipation and the loss of slave labor, and the difficulty of 

farming steep slopes. Agroforestry practices are part of the 

region’s tradition and have commercial benefits that include 

development of NTFPs, such as medicinal plants, arts and 

crafts materials, food, animal forage, resins, and oils (Morgan 

and Zimmerman 2014). Landowners may grow row or orchard 

crops with windbreaks, or they may combine animal production within orchards. Forest farming of plants used for the floral 

industry, food/culinary uses, or health supplements is well 

documented (Chamberlain et al. 2009, Robinson et al. 2014, 

Vaughan et al. 2011).

On Puerto Rico, some local artisans are using native and 

other locally grown wood to produce musical instruments and 

crafts. Shaded coffee production is most developed in western 

Puerto Rico and silvopasture in the southern landscape on 

more level land and alluvial plains, where greater livestock and 

cropping exist. More so than in the Southeastern States, the 

implementation of practices in the islands is frequently based 

more on cultural identity and inherited knowledge than on 
194 Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions

technical assistance. Exceptions may be beekeeping and honey 

production or growing high-value crops such as mushrooms. 

Planting traditional varieties of fruits (e.g., indigenous fruits 

like guavaberry [Myrciaria floribunda] or West Indian avocado 

[Persea americana var. americana]) or mixtures of culinary 

crops under tree shade are practices with cultural roots that 

support a pride in the sense of place.

In the U.S. islands, patio or dooryard gardens—a form of multistrata agroforestry used in both urban and rural settings—vary 

in their potential for ecosystem service provisioning and buffering climate change. Zones of management and cultivation often 

ring rural family dwellings, from a zone near the home patio, 

with materials for both aesthetic and food sources along with 

fruit trees to the next zone, with less intensive management 

but similar species and some soil enrichment practices. Living 

fences and field border plantings are sometimes incorporated.

Farther away, fields with less or little shade are used for open 

grazing or market crops and usually have fewer inputs. Areas 

with higher rainfall have some bananas and plantain agroforestry. Some places use trees to isolate chicken farms and mitigate 

odor. In the islands, riparian buffers could be managed to 

increase cover by adding woody components to what now is a 

“grass only” practice (USDA Natural Resources Conservation 

Service [NRCS] standard). Some discussion was begun in 2012 

regarding planting fruit tree crops, such as mamey (Mammea 

americana), açaí (Euterpe oleracea), and cacao (Theobroma 

cacao), in riparian zones (USDA Forest Service 2016) around 

El Yunque National Forest.

In the Southeast, frequent natural and sometimes human-caused 

fire created open presettlement woods and savannahs with 

grassy understories, where bison and elk once roamed. The 

Scotch-Irish who settled this region brought a tradition of 

grazing domestic stock, often with low stocking rates (5 to 10 

acres per head) and limited management. This history is noted 

in Wahlenberg’s 1946 book: “In accordance with age-old 

custom, southern landowners usually tolerate grazing on their 

forest lands by the livestock of numerous small famers. The 

typical forest range is open, no permits are required, no fees are 

charged, and usually no attempt is made to control fires set by 

stock owners” (Wahlenberg 1946: 309).

In a similar way, settlers to the Ozarks were grazing cattle on 

bluestem forage in the shortleaf-hardwood and hardwood forest 

as early as 1800. Graeber (1939) documented the effects of 

cattle, sheep, and pig “free range” woodland grazing on forest 

soils in North Carolina in the early 1930s in and around what is 

now the Great Smoky Mountains National Park (Lindsay and 

Bratton 2014). J. Russell Smith (1929), a formative advocate 

for soil and water conservation, outlined how to put trees 

to work as perennial crops to counter erosion, flooding, and 

“climatic peculiarities” to extend agriculture on hill slopes 

and marginal lands and also on level lands to create two-story 

agriculture (trees above and annual crops below). Raking pine 

straw for profit was also popular during this time (Mattoon 

1930). In 1930, W.R. Mattoon noted that a landowner in North 

Carolina “...makes regular income selling pine straw (leaves 

or needles) from his 10-acre patch of pines. He sells the straw 

on the ground at a rate of 25 cents per cartload. As an acre 

produces three to five loads, his net income is from 75 cents 

to $1.25 per acre yearly” (Mattoon 1930: 12). Fencing laws 

enacted in the 1930s eventually precluded livestock from freely 

wandering open forests, thus the practices of woodland grazing 

and burning largely disappeared from the landscape.

Modern agroforestry techniques take us beyond free-ranging 

cattle to science-based land management. In the Southeastern 

United States, agroforestry practices can help address threats 

posed by global climate change. In this region, riparian buffers 

are used extensively as a best management practice for water 

quality, however, most land managers and landowners do not 

often view their use as an agroforestry practice (Trozzo et al. 

2014a). Forest farming and silvopasture are other agroforestry 

practices that seem to have the most promise in the region 

(fig. A.18–A.22). Forest farming for medicinals or decorative 

and floral items provides additional income to landowners, thus 

improving livelihoods. North Carolina, Florida, and Georgia 

are considered to be pine-straw industry leaders (Mills and 

Robertson 1991). Estimates for market value range from a 1996 

pine-straw value of $50 million in North Carolina (Rowland 

2003) to a $79 million value for Florida in 2003 (Hodges et 

al. 2005). The State with the most detailed records regarding 

pine-straw production is Georgia, where data for pine straw is 

actually collected as a separate commodity. In 2012, pine straw 

Figure A.18. Pine-based silvopasture managed with cattle is perhaps the most common type of silvopasture in the 

Southeast. Cattle benefit both in summer and winter from the 

buffered environment created by the tree canopy cover. (Photo 

by USDA National Agroforestry Center).
Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions 195

Figure A.19. Small ruminants may be an important means of 

managing silvopastures. Goats and sheep can be instrumental 

in removing invasive weeds and stump sprouts that often develop in thinned tree stands. Goat silvopasture, Dallas County, 

AL; McIntire Stennis Forestry Research Program. (Photo by 

Nar Gurung, Tuskegee University).

Figure A.20. While it is most often used as a landscape mulch, 

pine straw is a nontimber forest product that is highly sought 

after in floral, craft and decorative markets (A). Pine straw and 

nontimber forest products crafts; Alabama-Coushatta Tribe 

longleaf pine needle baskets (B). (Photo by Beverly Moseley, 

USDA Natural Resources Conservation Service).

Figure A.21. In the Southeastern United States, pine straw 

is usually harvested from the forest floor of longleaf, slash, or 

loblolly stands, and may be compatible with many land uses 

including silvopasture. The open understory of a silvopasture 

allows for pine straw to be bailed by machine (A) or hand (B), 

and can provide an additional source of income for landowners. (Photos by Becky Barlow, School of Forestry and Wildlife 

Sciences, Auburn University). 

A

B

B

A
196 Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions

Figure A.22. Plants valued for traditional use and/or with high value in the supplements market are utilized in multistrata agroforestry systems. Cultivated in forest shade environments, these herbs provide an income stream and play a role in conservation of 

wild populations by reducing collection pressure. In this figure, goldenseal (Hydrastis canadensis) roots are ready for planting in 

Catawba, VA (A) and goldenseal cover under canopy (B). (Photos by Forest Farming Community of Practice).

accounted for 9.6 percent of Georgia’s forest products market, 

at $58.7 million. Successful silvopasture management requires 

good grazing management practices, which improve cattle 

waste management and forage production, and it also limits 

the amount of commercial feed used. Integrated crop-livestock 

agriculture, including tree crop systems, all contribute to 

carbon dioxide (CO2) sequestration and enhance soil fertility, 

water quality, and biodiversity (Sulc and Franzluebbers 2014). 

In the islands, these practices hold promise for the transition 

of abandoned pasture, shade coffee, or agricultural lands 

(Brandeis et al. 2009).

In Alabama, Florida, Georgia, Louisiana, and Mississippi, 

forest farming and silvopasture are common agroforestry 

practices. Of these 5 States, 4 were in the top 10 reported as 

participating in alley cropping or silvopasture in 2012 (table 

A.5). Harvesting pine straw is common and may actually 

motivate landowners to restore imperiled longleaf pine (Pinus 

palustris) ecosystems in the southern part of the Southeast. This 

restoration would accrue additional benefits, because longleaf 

pine forests are likely to be among the most resilient against 

the effects of expected future climatic changes, given their 

tolerance to wind, drought, fire, insects, and disease (Johnsen et 

al. 2009, Kush et al. 2004, Remucal et al. 2013).

Silvopasture is well suited to most southern pines and could 

benefit longleaf and shortleaf pine (P. echinata) restoration 

efforts across the region. With that restoration comes the opportunity to restore the understories of these systems, which were 

typically low and grassy, providing excellent habitat for native 

pollinators. Climate change, in turn, may benefit loblolly (P. 

taeda) and longleaf pine growth, which may respond positively 

to increases in atmospheric CO2

 and temperatures (Boyer 2001, 

Wertin et al. 2012, Whelan et al. 2013).

Opportunities and benefits for longleaf and shortleaf pine restoration on agroforestry sites west of the Mississippi River in States 

such as Arkansas are similar to those of other Southern States. 

Shortleaf and loblolly pine silvopastures may have the added 

benefit of mitigating the effects of ice storms (Burner and Ares 

2003) in these States of the “Glaze Belt,” which experienced 

a catastrophic ice storm event every 2 years in the period between 2000 and 2009 (Kovacik et al. 2010). For example, some 

Arkansas landowners are planting windbreaks along the edges 

of their pastures to provide shade and reduce the heat stress load 

for their stock and also to buffer other weather effects.

In the Upper Coastal Plain and Appalachian Highlands of 

Kentucky, North Carolina, South Carolina, Tennessee, and Virginia, all the agroforestry practices show promise for climate 

change mitigation and adaptation. Although the benefits of 

silvopasture and riparian buffers for soil stabilization, diffusion 

of animal waste, pollination, and plant diversity are similar 

to the benefits in other regions, the production of NTFPs and 

woodland medicinals is a customary focus (Vaughan et al. 

2013). Silvopasture has the potential to benefit lands making 

the transition from the conservation programs (e.g., USDA’s 

Conservation Reserve Program) to provide both annual and 

periodic income to landowners and to motivate them to actively 

manage their forests rather than converting them to pastureland 

or commercial/residential development.

Potential of and Limitations to Agroforestry

The ability to provide ecosystem services and mitigate the 

effects of climate change through agroforestry practices is great 

in the Southeast and Caribbean Region—provided adoption 

of agroforestry practices can be increased. The Southeast has 

A B
Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions 197

among the highest potential for carbon (C) storage and sequestration, and adding trees to mixed cropping and integrated 

crop-livestock systems offers several options to help maximize 

this potential (Franzluebbers et al. 2014; Schoeneberger et 

al. 2012). Along with their potential use in cropland systems, 

agroforestry practices can be deployed on rugged or sloping 

grounds as a means for addressing climate change challenges 

and meeting ecosystem services needs (Dosskey et al. 2012a, 

Smith et al. 2013).

In addition to increasing C storage (Haile et al. 2010), 

agroforestry practices can conserve soil and water by reducing 

runoff (Smith et al. 2013) and buffering streams (Dosskey et 

al. 2012b) while improving site conditions for wildlife habitat 

(Bowling et al. 2014; Rittenhouse and Rissman 2012) and 

providing safety-net goods (e.g., NTFP and firewood). The 

improved delivery of ecosystem services may simultaneously 

be accompanied by increased diversity and productivity of 

agricultural systems in the Southeast and Caribbean. Such 

improvements also may enhance cashflows to farm families 

and provide good return for the labor invested. Inroads have 

been made in promoting agroforestry with small land holders, 

beginning farmers, and minority farmers in the Southeast that 

could serve as models for advancing agroforestry adoption 

in other regions of the country. Increasing interest from these 

groups and the potential for them to apply agroforestry are 

notable through products and activities of the 1890s Agroforestry Consortium (Idassi 2012). Compared with traditional 

plantation forestry or agricultural systems, agroforestry 

techniques provide opportunities to diversify incomes, expand 

production, and enhance nonmarket benefits such as soil and 

water conservation and wildlife habitat. Systems with perennial 

components with their influence on microclimate and potential 

reduction of inputs and costs, while diversifying outputs and 

conservation, hold promise. Thus, agroforestry practices 

are viable options to enhance farm livelihoods and increase 

resilience of food systems while providing C storage and other 

conservation benefits (Fike et al. 2004, Russelle et al. 2007, 

Steiner and Franzluebbers 2009, Workman et al. 2004).

Constraints to adopting agroforestry practices include lack 

of technical knowledge and management skills and high 

establishment or annual management costs for some practices. 

Incompatibility between multiple components, potential for 

weedy species and pest interactions, and potential negative 

impacts of livestock on tree seedlings and soil productivity can 

be obstacles. The more important constraint is the long-term 

investment required, coupled with limited economic analysis, 

which remains a liability in promoting the systems.

Economic data and planning assistance (for intensity and 

timing of inputs and outputs), along with institutional and 

policy support (including finances and incentives), are needed 

to drive early-stage implementation of agroforestry systems. 

Market development for agroforestry products has increased 

in the past decade, with landowner information and public 

education. The value of nonmarket benefits is evident to many 

practitioners and motivates many to design and implement 

practices (Bentrup 2008, Fraisse et al. 2009, Workman et al. 

2005); however, it is often a constraint at higher levels of 

institutional and social policy (Lin et al. 2013, Merwin 1997). 

For example, at present no active market exists for carbon, 

though some industries may, in the future, be required to cap 

their emissions. Technology transfer needs for all agroforestry 

practices call for region- and situation-specific information to 

support design decisions based on research. Efforts to increase 

planting stock and improve genetic materials for tree resilience 

will help. More demonstration sites, training workshops, economic analysis, production budgets, marketing opportunities, 

and production effectiveness models are needed (fig. A.23). 

Technical designs must balance input availability and input 

quality and timing with production outputs and processing for 

various components and services.

Agroforestry practices have application potential over a range 

of land area sizes, from garden plots to total periphery of large 

park areas, from buffering and restoration of degraded sites to 

partitioning municipal landholdings, and, as envisioned for the 

Mississippi River and Chesapeake Bay watersheds, to serve as 

riparian buffer zones to guard against nonpoint source pollution 

and sedimentation. These integrated land-use practices can help 

bridge the gaps in the mosaic of land uses across a region and 

Figure A.23. Site tour and hands-on activities at the Trainer’s 

Training on Sustainable Agroforestry Practices in the Southeast 

Region, Atkins Agroforestry Research and Demonstration Site, 

Tuskegee University, Tuskegee, AL, conducted by the 1890s 

Agroforestry Consortium and funded by Southern Sustainable 

Agriculture Research and Education program. (Photo by Dr. 

Uma Karki, Tuskegee University).
198 Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions

serve as tools to strengthen the sustainable supply of goods and 

environmental services that society needs. Given that farming 

and plantation forestry have been rural economic mainstays 

compared with other development options in the region, ways 

that improve their value as a land use will continue to support 

rural communities and offer greater future land-use flexibility.

Agroforestry systems hold great potential in the Southeast and 

Caribbean Region and could likely be practiced in some form 

on more than 50 percent of the land area in most States and 

territories, with consideration of management intent, protected 

status, and limitations of soils and slope. Under good management, these systems can help provide increased resiliency and 

mitigation under changing moisture patterns and temperature 

extremes (Schoeneberger et al. 2012, Sulc and Franzluebbers 

2014). The economic value of these systems, particularly in the 

event of climate change, has not been well defined, however. 

Realizing their potential likely will require more active 

management than commonly practiced. Greater understanding 

and capacity of service providers to promote agroforestry as 

an integrated approach, coupled with focused research and 

landowner innovation, is needed to push these systems forward 

in practical ways that will meet economic and environmental 

goals in the face of climate change foreseen for the region 

(Franzluebbers et al. 2014, Howden et al. 2007, Ingram et al. 

2013, Kunkel et al. 2013, Vose et al. 2012).

Greater use of available scientific tools is needed for better 

decisionmaking, considering the complexity of agroforestry 

with its diversity of species, field conditions, and management 

options in use. Some policy and programmatic review (e.g., 

buffer practice sheets, forest health monitoring, resource 

inventory) would support decision tools and benefit the region. 

Landowners have to perceive the practices as valuable, whether 

in terms of income and livelihood, in terms of aesthetics and 

land ethics, or with belief in stewardship and resilience for the 

future. The U.S. Department of the Interior Southeast Climate 

Science Center (CSC) is one of eight regional CSCs and works 

with the USDA Caribbean Climate Sub Hub and Southeast 

Regional Climate Hub. These centers, along with their partners 

concerned with landscape conservation (e.g., http://lccnetwork.

org/OurWork/DecisionTools) or social vulnerability (e.g., 

Oxfam), have tools to contribute to decisionmaking efforts. 

Development of models (such as Carbon Management 

Evaluation Tool for Voluntary Reporting [COMET-VR] from 

USDA NRCS), measurement protocols (such as GRACEnet 

from USDA ARS), and monitoring/reporting tools (such as the 

Forest Change Assessment Viewer [ForWarn] and Template 

for Assessing Climate Change Impacts and Management 

Options [TACCIMO] from USDA Forest Service) reflect the 

expertise and opportunity for climate mitigation and adaptation 

using agroforestry in the Southeast and Caribbean Region.

Key Information Needs

• Development of strategies to help transition lands coming 

out of Conservation Reserve Program contracts into 

sustainable agroforestry systems.

• Identification of appropriate forage species and their 

management in silvopasture systems over the range of tree 

species and densities that might be utilized in the diverse 

ecosystems of the Southeast.

• Better understanding of how to incentivize and integrate the 

development of silvopasture systems within a whole-farm 

(or whole-plantation) context in order to increase ecosystem 

services, sequester carbon, and other conservation goals.

• Development of tools to assist with nonmarket valuation 

and marketing of nontimber forest products sustainably 

harvested from agroforestry systems.

• Identification of strategies to spur innovation and adoption of 

alley cropping systems in the region.

Acknowledgments

The maps and data in figs. A.15 and A.16 were provided by 

Bill Christie, USDA Forest Service, Southern Research Station, 

Asheville, NC. The authors appreciate assistance and information 

provided by Alan Franzluebbers, USDA Agricultural Research 

Service; Emily Stutzman-Jones, Auburn University; Uma Karki, 

Tuskegee University; Steve Norman, USDA Forest Service, 

Southern Research Station; William Gould and Kathleen 

McGinley, USDA Forest Service, International Institute of 

Tropical Forestry; Katie Trozzo, John F. Munsell, and Paxton 

Ramsdell, Virginia Polytechnic Institute and State University; 

State Extension representatives in Arkansas, North Carolina, 

and Tennessee; and Brian Daley, Geographic Consulting, U.S. 

Virgin Islands. Both the U.S. Virgin Islands Forest Resources 

Assessment and Strategy by Marilyn Chakroff, Virgin Islands 

Department of Agriculture, and the Puerto Rico Statewide Assessment and Strategies for Forest Resources from the Department 

of Natural and Environmental Resources of Puerto Rico, along 

with comments from Magaly Figeroa, Connie Carpenter, and 

Felipe Cano, USDA Forest Service, and Edwin Más, USDA 

Natural Resources Conservation Service, were invaluable for 

the U.S. Caribbean portion of this regional description.

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Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions 203

Appendix B

Risk-Based Framework and Assessments 

of Agroforestry as a Climate Change 

Adaptation and Mitigation Strategy

Risk-Based Framework for Evaluating 

Adaptation and Mitigation Strategies

Michael G. Dosskey, W. Keith Moser, Gary Bentrup, and Thomas B. Treiman

Michael G. Dosskey is a research ecologist (retired), U.S. Department of Agriculture (USDA), Forest 

Service, USDA National Agroforestry Center; W. Keith Moser is a research forester, USDA Forest Service, 

Rocky Mountain Research Station; Gary Bentrup is a research landscape planner, USDA Forest Service, 

USDA National Agroforestry Center; Thomas B. Treiman is a resource economist, Missouri Department of 

Conservation, Central Regional Office and Conservation Research Center.

The effectiveness of an agroforestry strategy for adapting agriculture to climate change or for mitigating it can be evaluated 

within a risk-based framework. Such a framework has been 

used to evaluate hazards from climate change (Iverson et al. 

2012, Yohe 2010). The same approach can be used to evaluate 

adaptation and mitigation strategies. The framework describes 

both the likelihood that a strategy will have a positive impact 

and the magnitude of that impact (fig. B.1). A highly effective 

strategy has a high probability or likelihood of occurring or 

Figure B.1. A matrix illustrating the framework for identifying 

better strategies for adapting to or mitigating climate changes. 

(Adapted from Iverson et al. 2012, Yohe and Leichenko 2010). 

A highly effective strategy (dark green) has a high likelihood of 

occurring (or being implemented) and a high level of positive 

impact. Strategies that would have minimal effectiveness (light 

brown) have a low probability of occurring and a low magnitude 

of impact.

being implemented and also has a high magnitude of positive 

impact. A strategy that has a high magnitude of impact is less 

effective if it has a low probability of occurring. Strategies that 

are minimally effective have a low magnitude of impact and a 

low probability of occurring. This framework can be applied 

to evaluate and compare potential adaptation strategies by 

organizing thoughts along two dimensions—likelihood and 

consequence. The results will help managers and decisionmakers prioritize management options.

In a qualitative definition of impact—

• Low = the strategy will have an insignificant impact.

• Medium = the strategy will have a measurable and potentially significantly positive impact.

• High = the strategy will produce a large positive impact of 

critical importance.

In a qualitative definition of likelihood—

• Low = an impact of the strategy is deemed to be unlikely to 

occur.

• Medium = an impact of the strategy is deemed to be likely 

to occur.

• High = an impact of the strategy is deemed to be very likely 

to occur.
204 Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions

The process of developing strategies begins with an assessment 

of risk, starting with identification of current and future climate 

hazards (step 1 in fig. B.2) and followed by an inventory of 

at-risk assets (step 2 in fig. B.2). A future hazard can be a 

particular or aggregate threat of climate change on a particular 

resource or service. The risk framework can be used to evaluate 

the level of climate change risk to various resources and 

services (step 3 in fig. B.2). The risks that climate change poses 

for U.S. agriculture have been recently evaluated by the USDA 

(Walthall et al. 2012); their pervasive scope is one of the fundamental insights of the National Climate Assessment (Melillo et 

al. 2014). That assessment covers both effects on agricultural 

production (e.g., reduced crop yield) and on environmental 

resources (e.g., soil erosion).

Figure B.2. Flowchart of an adaptation/mitigation planning 

process. Risk management begins with the development of 

strategies for adaptation and mitigation (step 4) that reduce 

risks to agricultural resources and services identified in step 3. 

(Adapted from Carnesale et al. 2010, Yohe 2010).

Adaptation strategies, such as agroforestry practices, can also 

be evaluated by using the risk framework (step 4 in fig. B.2). 

The effectiveness of an agroforestry strategy is determined by 

comparing the level of risk (calibrated in terms of likelihood 

and impact) without adaptation with the risk level if a given 

agroforestry strategy were implemented. Because risks can also 

be influenced by changes in various agronomic practices (e.g., 

crop types, cultivation practices) not related to agroforestry, 

a key challenge for managers is to determine an appropriate 

balance of agronomic and agroforestry practices for providing 

desirable outcomes. Assessing agroforestry options by 

themselves (that is, by assuming that other agronomic practices 

remain unchanged) will provide a clear baseline condition from 

which to make these determinations.

The risk-based framework and underlying concepts are used 

in the following case studies. These case studies are intended 

as examples of different ways to convey risk and to evaluate 

benefits and tradeoffs. Scientists and managers can use the 

framework and concepts for assessing adaptation strategies for 

a wide range of impacts on threatened agricultural resources. 

As readers consider these case studies, they may wish to keep 

in mind that different decisionmakers may have different 

perceptions about the likelihood of occurrence and magnitude 

of impact.

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Carnesale, A.; Chameides, W.; Boesch, D.F. [et al.]. 2011. 

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Press. 144 p.

Iverson, L.R.; Matthews, S.N.; Prasad, A.M. [et al.]. 2012. 

Development of risk matrices for evaluating climatic change 

responses of forested habitats. Climate Change. 114(2): 

231–243.

Melillo, J.M.; Richmond, T.C.; Yohe, G.W., eds. 2014. Climate 

change impacts in the United States: the third national climate 

assessment. Washington, DC: Global Change Research 

Program. 841 p.

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change and agriculture in the United States: effects and adaptation. Tech. Bull. 1935. Washington, DC: U.S. Department of 

Agriculture. 186 p.

Yohe, G. 2010. Risk assessment and risk management for 

infrastructure planning and investment. The Bridge. 40(3): 

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Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions 205

Evaluation of Agroforestry for Reducing Soil 

Erosion

Michael G. Dosskey

Michael G. Dosskey is a research ecologist (retired), U.S. Department of Agriculture (USDA), Forest Service, 

USDA National Agroforestry Center.

Implementation of agroforestry on U.S. farmlands can offset 

predicted increases in soil erosion due to climate change 

(Walthall et al. 2012). Agricultural tillage exposes soil to 

erosion by excessive rainfall. Agroforestry practices stabilize 

and protect soil from erosion. The reduction of erosion will be 

very large where agroforestry is implemented, but reluctance 

by many landowners to implement it could severely limit the 

magnitude of impact at a national scale (fig. B.3).

Figure B.3. Likelihood of occurrence and impact of agroforestry 

implementation on the predicted increase in soil erosion due to 

climate change. At the site scale, implementation of agroforestry 

can offset the predicted increase in soil erosion due to climate 

change (circle). At a national scale, however, the impact will 

be low, because most landowners are currently reluctant to 

implement agroforestry on their farms (triangle). National-scale 

effectiveness would be higher (arrow) if market conditions and 

program incentives, among other factors that affect landowner 

decisions, become more favorable for adoption of agroforestry 

and the aerial extent of implementation increases.

Soil loss is a major threat to long-term sustainability of agricultural production and other ecosystem services. Erosion by 

large, high-intensity rainfall events is a major cause of soil loss 

from cultivated fields (Larson et al. 1997; SWCS 2003, 2006). 

Climate change is predicted to increase the magnitude and 

intensity of rainfall events across most of the United States and, 

in the absence of protective measures, to increase rates of soil 

erosion (Garbrecht et al. 2014; SWCS 2003, 2006; Walthall et 

al. 2012).

Implementation of agroforestry practices can reduce soil erosion from cultivated fields and moderate the predicted increases 

in erosion rates that will come with climate change. The rate 

of erosion depends on many factors, including precipitation 

amount and intensity, soil characteristics, topography of the 

terrain, and land cover characteristics. Climate change is 

predicted to increase erosion mainly by increasing precipitation 

intensity. A change in land cover from a completely cultivated 

condition to an appropriate agroforestry practice can reduce the 

vulnerability of the soil to erosion and can offset the effects of 

increased precipitation intensity.

Contour buffers (also called contour stripcropping and buffer 

stripcropping) (Wischmeier and Smith 1978), in which the 

protective vegetation cover is placed in a strip configuration on 

topographic contours, are a recommended practice for reducing 

soil erosion. They function to reduce the erosive power of 

overland runoff during large rainfall events and stabilize soil 

against erosion. Agroforestry in the form of alley cropping can 

be configured into contour buffers and function like contour 

buffers.

The potential for erosion reduction by implementing agroforestry can be estimated using concepts and relationships from 

the Universal Soil Loss Equation (USLE) (Wischmeier and 

Smith 1978). In the USLE, soil loss is predicted for a given pattern of precipitation (local amounts, frequencies, and intensities 

determined from local weather data) on an agricultural field 

having a standard set of site conditions (soil, topographic, soil 

cover, and land cover). That soil loss value, called the Rainfall 

and Erosion Index (R), is adjusted to other site conditions by 

the amount that those site conditions differ from the standard 

set. Adjustments are expressed as a ratio of soil loss under 

actual site conditions compared with that under the standard 

set. Thus, a site condition that reduces an adjustment factor 

ratio by, say, 0.25, translates into a reduction of soil loss by 

25 percent. Based on the USLE, properly designed contour 

buffers consisting of fall-planted small grains can reduce the 

ratio for an otherwise spring-cultivated corn field by about 0.50 

(Wischmeier and Smith 1978) and, thus, the erosion rate by 

about 50 percent. In a field experiment, Udawatta et al. (2011) 

measured a 28- to 30-percent reduction in annual soil loss over 

a 5-year period from fields planted with agroforestry contour 

buffers consisting of perennial grasses and trees.
206 Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions

The impact that alley cropping in a contour buffer configuration can have on climate change-enhanced erosion rates can 

be estimated by comparing erosion reduction by implementing 

the agroforestry practice to the magnitude of erosion increase 

predicted by climate change. The average R (under standard 

site conditions) for the conterminous United States is estimated 

to increase between 16 and 58 percent during the 21st century 

(Nearing 2001, Nearing et al. 2004). Others (e.g., O’Neal et 

al. 2005, Segura et al. 2014) have predicted similarly large 

increases in erosion rates. Estimates of future increases in 

soil erosion are similar in magnitude to the amount by which 

implementation of alley cropping could reduce soil erosion 

from a field. On this basis, agroforestry may be capable of 

completely offsetting any increase in erosion that a future 

climate would cause (fig. B.3). If combined with additional 

protective measures, such as no-till, residue management, or 

cover crops, erosion rates could be reduced still further.

The total mass of eroded soil would be reduced by a greater 

amount if agroforestry were applied to fields in regions where 

the increase in soil erosion rate would be relatively greater. 

Segura et al. (2014) predicted greater increases in the threat 

of erosion in the Eastern and Northwestern United States and 

decreases in the Central Great Plains. On this basis, agroforestry for soil erosion control under climate change may provide 

greater benefit if focused on the northern tier and Eastern U.S. 

croplands. Uncertainty associated with a regional focus is high, 

however, because spatial distribution of predicted changes in 

erosion differs widely, depending on which climate change 

model is used (Nearing 2001, O’Neal et al. 2005, Segura et al. 

2014).

At the national scale, the impact that agroforestry can have may 

be small—hindered by landowner resistance to adoption and 

limited extent of sites that are most suitable for alley cropping 

(fig. B.3). Landowners view agroforestry as more complex 

than they are willing to deal with. From that perspective, some 

land is taken out of the cropping system that they are familiar 

with and put into a system that they do not know as well. This 

change creates financial risk because they are less familiar with 

the new crop and it increases complexity because they have to 

manage for two crops instead of one. Management practices for 

their traditional crop are made more difficult by having to work 

around the trees. In combination, agroforestry makes more 

work for farmers and raises financial risk for the landowner. 

Incentive programs that offer financial and technical assistance 

have had very little success in achieving adoption of alley 

cropping. Furthermore, the magnitude of impact at the national 

scale will be limited by the aerial extent of implementation. For 

national-scale estimations of agroforestry impacts, Udawatta 

and Jose (2012) used a value of 10 percent of U.S. cropland. 

That would leave 90 percent of U.S. croplands requiring other 

protective measures to counter soil erosion due to climate 

change.

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Impact of weather and climate scenarios on conservation 

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Larson, W.E.; Lindstrom, M.J.; Schumacher, T.E. 1997. 

The role of severe storms in soil erosion: a problem needing 

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90–95.

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the U.S. with climate change during the 21st century. Journal 

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Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions 207

Evaluation of Agroforestry for Protecting 

Coldwater Fish Habitat

Gary Bentrup and Michael G. Dosskey

Gary Bentrup is a research landscape planner, U.S. Department of Agriculture (USDA), Forest Service, USDA 

National Agroforestry Center; Michael G. Dosskey is a research ecologist (retired), USDA Forest Service, 

USDA National Agroforestry Center.

The implementation of agroforestry practices on U.S. agricultural lands can offset predicted increases in stream temperatures 

due to climate change, thereby protecting coldwater habitat for 

salmon, trout, and related fishes. Riparian forest buffers can 

moderate the rise in stream temperatures in watersheds where 

they are implemented, but the magnitude of impact on the 

aerial extent of favorable fish habitat, at both local and national 

levels, will be low if landowners are reluctant to implement 

agroforestry on their farms (fig. B.4).

Figure B.4. The likelihood of occurrence and impact of agroforestry implementation on stream temperatures in agricultural 

areas. The implementation of agroforestry practices can offset 

predicted increases in stream temperatures due to climate 

change, thereby protecting coldwater habitat for salmon, trout, 

and related fishes. Riparian forest buffers can moderate the rise 

in stream temperatures in watersheds where they are implemented thoroughly (circle). At a national scale, however, the impact 

will be low, because many landowners are currently reluctant to 

implement agroforestry on their farms (triangle). National-scale 

effectiveness would be higher (arrow) if market conditions and 

program incentives, among other factors that affect landowners’ 

decisions, become more favorable for the adoption of agroforestry and the aerial extent of implementation increases.

Salmon, trout, char, grayling, and whitefish (collectively called 

salmonids) are a significant ecological, commercial, recreational, and cultural resource in the United States. A number 

of these species are listed under the Federal Endangered 

Species Act and face increasing pressures under climate change 

(Mantua et al. 2010). Water temperature is a key factor in 

determining habitat suitability for salmonids, and excessively 

high water temperature can act as a limiting factor for the 

distribution, migration, health, and performance of salmonids 

(McCullough 1999). As temperatures rise, salmon become 

more susceptible to disease, and prolonged exposure to stream 

temperatures across a threshold can be lethal for juveniles and 

adults (McCullough 1999). Climate change is predicted to 

increase air temperatures and the frequency and magnitude of 

droughts, all of which, in turn, lead to higher water temperatures in streams and rivers (Melillo et al. 2014, Mohseni et 

al. 1999). Water temperatures have been increasing in many 

streams and rivers throughout the United States during the past 

several decades (Kaushal et al. 2010).

Riparian forest buffers can reduce the effect of climate change 

on stream temperature and salmonids. Solar radiation received 

by a stream is one of the most influential factors affecting 

stream temperatures (Brown and Krygier 1970, Caissie 2006). 

Riparian forest buffers provide shade, reducing solar radiation 

received by a stream, leading to lower summer water temperatures and a reduction in stream temperature fluctuations (Barton 

et al. 1985, Bowler et al. 2012, Brown and Krygier 1970). The 

implementation of riparian forest buffers along salmonid-bearing streams that currently lack shade can help offset increases 

in stream temperatures due to climate change.

Preferred temperatures for salmonids vary by species and life 

history stage; however, temperatures above maximum weekly 

temperature thresholds indicate habitat loss and increased 

mortality. For most salmonids in the United States, the 

maximum weekly temperature thresholds range between 21 and 

24 °C (Eaton et al. 1995).

Maximum weekly stream temperatures are projected to increase 

from 1 to 3 °C across the continental United States, based on 

a climate scenario in which the atmospheric concentration of 

carbon dioxide is doubled from 330 to 660 parts per million 

(ppm) (Mohseni et al. 1999). It is estimated that the 660 ppm 

level could be reached by the end of this century (Karl et al. 

2009). In response, maximum weekly stream temperatures are 

predicted to be 18 to 24 °C in the Rocky Mountains and on the 

West Coast, 22 to 26 °C in the upper Mississippi River basin 

and on the East Coast, and 26 to 30 °C in the lower Mississippi 
208 Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions

River basin and portions of the South (Mohseni et al. 1999). 

Under this climate scenario, the number of U.S. Geological 

Survey stream-gauging stations nationwide indicating suitable 

thermal habitat for coldwater fishes is projected to decrease 36 

percent (Mohseni et al. 2003).

Riparian forest buffers can maintain lower maximum summer 

stream temperatures by 3.3 °C compared with streams without 

buffers and lower summer mean stream temperatures by 0.6 °C 

based on a meta-analysis of 10 studies (Bowler et al. 2012). On 

this basis, implementing riparian forest buffers may be capable 

of offsetting the projected increases in maximum summer 

stream temperatures and maintaining those temperatures 

below critical thresholds in most regions currently containing 

salmonids.

In one geographically specific case, Wisconsin is recognized 

for its abundance of coldwater streams, which include more 

than 10,000 miles of classified trout streams that provide 

fisheries for brook trout (Salvelinus fontinalis) and brown 

trout (Salmo trutta) (WDNR 2002). Three future climate 

scenarios for Wisconsin predict (1) a “best case” scenario in 

which summer air temperature increases by 1.0 °C and water 

temperature by 0.8 °C, (2) a “moderate case” in which summer 

air temperature increases by 3.0 °C and water temperature by 

2.4 °C, and (3) a “worst case” in which summer air temperature 

increases by 5.0 °C and water temperature by 4.0 °C (Lyons et 

al. 2010). Under the worst-case climate scenario, fish habitat 

suitability models predict brook trout to be eliminated from all 

Wisconsin streams and brown trout habitat, based on stream 

length, to decrease by 88 percent (Lyons et al. 2010). Even 

under the moderate scenario, brook trout habitat is expected 

to decrease by 94 percent; the best case scenario predicts a 

44-percent loss of habitat (Lyons et al. 2010).

Increasing riparian shade on Wisconsin streams can substantially reduce stream temperatures. Based on a heat-transfer model, 

Cross et al. (2013) predicted maximum weekly temperature 

would decrease by 4.8 °C as stream shading increased from 0 

to 75 percent and Gaffield et al. (2005) predicted temperature 

would decrease by 4.5 °C as stream shading increased from 0 

to 80 percent. These predictions indicate that the establishment 

of riparian forest buffers may be capable of offsetting the 

projected increases in water temperatures in Wisconsin streams 

due to future climate change. Agriculture occupies 43 percent 

of the land area in Wisconsin. Riparian areas are frequently 

embedded in watersheds where agriculture is the primary 

activity (Wang et al. 1997), suggesting a high potential exists 

for implementing riparian forest buffers to protect trout from 

rising stream temperatures.

If mean summer water temperatures are already at or above 

critical temperature thresholds before projected climate change, 

the implementation of riparian forest buffers may not be enough 

to bring these temperatures below critical thresholds under a 

future warmer climate. A useful implementation strategy will 

be one that targets areas identified as those where riparian 

forest buffers can have the most impact (Cross et al. 2013).

Stream thermal regimes are quite complex and are influenced 

by many factors, including stream discharge, streambed 

conduction, air temperature, wind speed, channel morphology, 

groundwater inputs, and surrounding land use, in addition to 

solar radiation (Caissie 2006). In some cases, riparian forest 

buffers may increase stream widening, leading to shallower 

flows and increased solar exposure on the water surface, 

which could potentially offset the temperature reductions from 

riparian shade (Allmendinger et al. 2005, McBride et al. 2008). 

This complexity raises the uncertainty of the overall impact of 

riparian forest buffers on stream temperatures.

The likelihood of impact will be greatly influenced by the 

likelihood that landowners will adopt riparian forest buffers. 

Farmers and ranchers generally dislike riparian forest buffers 

because they view them as taking land out of production 

(Gillespie et al. 2007, Luloff et al. 2012). Piecemeal implementation of riparian forest buffers may diminish the magnitude of 

impact at a national scale or even at watershed scales. Programs offering financial incentive and technical assistance have 

had some success in increasing the adoption of riparian forest 

buffers. Nontimber forest products (e.g., nuts, fruits, medicinal 

plants, decorative materials) can be produced from riparian 

forest buffers, generating income for landowners willing to 

harvest and sell the products. It is unclear, however, how many 

landowners might be interested in this enterprise option.

Literature Cited

Allmendinger, N.E.; Pizzuto, J.E.; Potter, N. [et al.]. 2005. 

Riparian vegetation and width adjustment in laterally migrating 

rivers of eastern Pennsylvania, U.S.A. Geological Society of 

America Bulletin. 117(1–2): 229–243.

Barton, D.R.; Taylor, W.D.; Biette, R.M. 1985. Dimensions 

of riparian buffer strips required to maintain trout habitat in 

southern Ontario streams. North American Journal of Fisheries 

Management. 5(3A): 364–378.

Bowler, D.E.; Mant, R.; Orr, H. [et al.]. 2012. What are the 

effects of wooded riparian zones on stream temperature? 

Environmental Evidence. 1(3): 1–9. http://www.

environmentalevidencejournal.org/content/1/1/3. (21 October 

2016).

Brown, G.W.; Krygier, J.T. 1970. Effects of clear-cutting on stream 

temperature. Water Resources Research. 6(4): 1133–1139.

Caissie, D. 2006. The thermal regime of rivers: a review. 

Freshwater Biology. 51(8): 1389–1406.
Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions 209

Cross, B.K.; Bozek, M.A.; Mitro, M.G. 2013. Influences of 

riparian vegetation on trout stream temperatures in central 

Wisconsin. North American Journal of Fisheries Management. 

33(4): 682–692.

Eaton, J.G.; McCormick, J.H.; Goodno, B.E. [et al.]. 1995. A 

field information-based system for estimating fish temperature 

tolerances. Fisheries. 20(4): 10–18.

Gaffield, S.J.; Potter, K.W.; Wang, L. 2005. Predicting the 

summer temperature of small streams in southwestern Wisconsin. Journal of the American Water Resources Association. 

41(1): 25–36.

Gillespie, J.; Kim, S.; Paudel, K. 2007. Why don’t producers 

adopt best management practices? An analysis of the beef 

cattle industry. Agricultural Economics. 36(2007): 89–102.

Karl, T.R.; Melillo, J.M.; Peterson, T.C., eds. 2009. Global 

climate change impacts in the United States. U.S. Global 

Change Research Program. New York: Cambridge University 

Press. 188 p.

Kaushal, S.S.; Likens, G.E.; Jaworski, N.A. [et al.]. 2010. Rising 

stream and river temperatures in the United States. Frontiers in 

Ecology and the Environment. 8(9): 461–466.

Luloff, A.E.; Hoag, D.L.K.; Osmond, D.L. [et al.]. 2012. Key 

informant survey to understand what farmers, agency personnel, and stakeholders think. In: Osmond, D.L. [et al.], eds. How 

to build better agricultural conservation programs to protect 

water quality: the National Institute of Food and Agriculture-conservation effects assessment project experience. Ankeny, 

IA: Soil and Water Conservation Society: 12–35.

Lyons, J.; Stewart, J.S.; Mitro, M. 2010. Predicted effects 

of climate warming on the distribution of 50 stream fishes in 

Wisconsin, USA. Journal of Fish Biology. 77(8): 1867–1898.

Mantua, N.; Tohver, I.; Hamlet, A. 2010. Climate change 

impacts on streamflow extremes and summertime stream 

temperature and their possible consequences for freshwater 

salmon habitat in Washington State. Climatic Change. 102(1): 

187–223.

McBride, M.; Hession, W.C.; Rizzo, D.M. 2008. Riparian 

reforestation and channel change: a case study of two small 

tributaries to Sleepers River, northeastern Vermont, USA. 

Geomorphology. 102(2008): 445–459.

McCullough, D.A. 1999. A review and synthesis of effects of 

alterations to the water temperature regime on freshwater life 

stages of salmonids, with special reference to Chinook salmon. 

Water Resources Assessment Report No. 910-R-99-010. 

Seattle, WA: Environmental Protection Agency. 291 p.

Melillo, J.M.; Richmond, T.C.; Yohe, G.W., eds. 2014. Climate 

change impacts in the United States: the Third National Climate 

Assessment. Washington, DC: U.S. Global Change Research 

Program. 841 p. doi:10.7930/J0Z31WJ2.

Mohseni, O.; Erickson, T.R.; Stefan, H.G. 1999. Sensitivity of 

stream temperatures in the United States to air temperatures 

projected under a global warming scenario. Water Resources 

Research. 35(12): 3723–3733.

Mohseni, O.; Stefan, H.G.; Eaton, J.G. 2003. Global warming 

and potential changes in fish habitat in U.S. streams. Climatic 

Change. 59(3): 389–409.

Wang, L.; Lyons, J.; Kanehl, P. [et al.]. 1997. Influences of 

watershed land use on habitat quality and biotic integrity in 

Wisconsin streams. Fisheries. 22(6): 6–12.

Wisconsin Department of Natural Resources (WDNR). 2002. 

Wisconsin trout streams. Madison, WI: Bureau of Fisheries 

Management and Habitat Protection. 94 p.
210 Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions

Evaluation of Agroforestry for Carbon 

Sequestration

Michael G. Dosskey

Michael G. Dosskey is a research ecologist (retired), U.S. Department of Agriculture (USDA), Forest Service, 

USDA National Agroforestry Center.

Implementation of agroforestry practices can help moderate 

effects of climate change through sequestration of carbon 

(C). Trees in agroforestry practices absorb and store larger 

quantities of atmospheric carbon dioxide (CO2)than do the 

herbaceous annual crops they would replace. This case study 

assessment indicates that the potential impact of agroforestry 

implementation on concentration of CO2 in the atmosphere is 

likely to be small but measurable if implemented extensively 

but that the likelihood of widespread adoption under current 

economic conditions is low (fig. B.5).

Figure B.5. Likelihood of occurrence and impact of agroforestry 

implementation on U.S. farmlands on global atmospheric CO2

concentration. The impact will be low but measurable if implemented on 10 percent of U.S. farmland and along 5 percent of 

river miles, but the likelihood of achieving that level of implementation (circle) is low under current market conditions and program 

incentives, among other factors that affect adoption by landowners. The likelihood of occurrence would rise (arrow) if those 

factors become more favorable for adoption of agroforestry and 

the aerial extent of implementation increases.

Atmospheric concentrations of greenhouse gases, of which 

CO2 is a major component, are rising and are considered to be 

largely responsible for a changing global climate. The absorption and sequestration of the C in CO2

 are viewed as strategies 

for limiting the increase of atmospheric CO2, climate change, 

and the effects of a changing climate on Earth’s systems and 

resources. Total global C emissions as CO2 in 2012 were 

estimated to be 9,825 million metric tons (GCP 2014). That 

emission rate is raising the concentration of atmospheric CO2

by approximately 2 parts per million (ppm) per year, which 

stood at 391 ppm in 2012 (NOAA ESRL 2014). Total U.S. C 

emissions as CO2 in 2012 was estimated to be 1,460 million 

metric tons of C (U.S. EPA 2014), or about 15 percent of the 

global total.

Forests can be important contributors to C sequestration. 

Forest vegetation absorbs and converts atmospheric CO2

 into C 

compounds in plant biomass. The C is stored for long periods 

in wood and recalcitrant degradation products like soil organic 

matter. Afforestation (i.e., the conversion of herbaceous 

cover to forest cover) has the capability of increasing the 

total amount of C that can be stored on the land. Agroforestry 

implementation on agricultural land can be viewed as a form of 

afforestation. A risk-based framework can be used to assess the 

C sequestration potential of afforesting agricultural lands with 

agroforestry practices.

Agroforestry implementation can mitigate climate change to 

the extent that its rate of C sequestration is significant compared with total C (as CO2

) emissions. Potential C sequestration 

rates after adopting agroforestry practices in the United States 

(including silvopasture, alley cropping, windbreaks, and 

riparian forest buffers) on 10 percent of current U.S. cropland 

and pastureland and 5 percent of total river length (42 mega 

hectares, or an area about the size of the State of California) 

have been estimated to be 90 to 219 million metric tons of C 

per year (Nair and Nair 2003, Udawatta and Jose 2012). These 

estimates put the potential agroforestry sequestration rate at 

about 1 to 2 percent of the global CO2

 emission rate in 2012 

and 6 to 15 percent of the U.S. CO2 emission rate. At most, 

then, the rate of increase in global atmospheric CO2 concentration would be slowed by about 2 percent of the 2012 rate or 

0.045 ppm per year. Assuming that current agricultural systems 

have been in place long enough to have reached a steady state 

of C stocks (net C sequestration rate = 0), then these values 

fairly represent the potential effect of implementing agroforestry on agricultural lands in the United States.
Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions 211

A high C sequestration rate is unlikely to be sustainable in the 

long term without active management. Rates can be expected 

to fall as agroforests mature and approach a natural steady state 

of aboveground and belowground C stocks—possibly within 

50 to 100 years of implementation. A high sequestration rate 

can be partially sustained for a longer term to the extent that the 

standing stock of plant biomass is harvested and preserved in 

the form of wood products like structural lumber.

Based on this analysis, the potential for agroforestry implementation in the United States to moderate global atmospheric CO2

concentrations is probably small but still significant (fig. B.5). 

Agroforestry could contribute substantially toward reducing 

the U.S. footprint (by 6 to 15 percent) on the global increase 

of atmospheric CO2. Furthermore, this rate could contribute 

substantively to a global effort that includes additional 

mitigation approaches. Its impact, however, will depend 

largely on how widely agroforestry is implemented. There are 

substantial technical and sociological headwinds for achieving 

the implementation rates that are assumed in this analysis.

Literature Cited

Global Carbon Project (GCP). 2014. Global carbon budget. 

Canberra, Australia: Global Carbon Project. http://www.

globalcarbonproject.org/carbonbudget/archive.htm. (20 

October 2016).

Nair, P.K.R.; Nair, V.D. 2003. Carbon storage in North 

American agroforestry systems. In: Kimble, J.M. [et al.], eds. 

The potential of U.S. forest soils to sequester carbon and 

mitigate the greenhouse effect. Boca Raton, FL: CRC Press: 

333–346.

National Oceanic and Atmospheric Administration, Earth 

System Research Laboratory (NOAA ESRL). 2014. Trends in 

atmospheric carbon dioxide. Washington, DC: U.S. Department of Commerce. http://www.esrl.noaa.gov/gmd/ccgg/

trends/. (20 October 2016).

Udawatta, R.P.; Jose, S. 2012. Agroforestry strategies to 

sequester carbon in temperate North America. Agroforestry 

Systems. 86(2): 225–242.

U.S. Environmental Protection Agency (U.S. EPA). 2014. 

Inventory of U.S. greenhouse gas emissions and sinks: 

1990–2012. EPA-430-R-14-003. Washington, DC: U.S. 

Environmental Protection Agency. 529 p. https://www3.epa.

gov/climatechange/Downloads/ghgemissions/US-GHG-Inventory-2014-Main-Text.pdf (21 October 2016).
212 Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions

Suitable Tree Species Under a Changing 

Climate

Michael G. Dosskey, Andrew C. Bell, and Gary Bentrup

Michael G. Dosskey is a research ecologist (retired), U.S. Department of Agriculture, Forest Service, USDA 

National Agroforestry Center; Andrew C. Bell is a Longwood fellow, Longwood Gardens, and visiting 

scientist, National Arboretum; Gary Bentrup is a research landscape planner, U.S. Department of Agriculture, Forest Service, USDA National Agroforestry Center.

Successful agroforestry practices depend on the ability of the 

trees to survive and grow well enough to provide the benefits 

sought. Local climate is a major factor in determining which 

tree species could be effective in an agroforestry practice, and 

a great deal of variability in this regard exists among different 

species. As climate changes, local climate can shift beyond 

tolerable thresholds for some species and move to within 

tolerable thresholds for other species (table B.1). In a changing 

climate, agroforestry species must be able to survive and grow 

under both current and future climatic conditions. If species 

that are currently used cannot adapt to future climate, risk is 

high that the desired functional lifespan of the agroforestry 

practice will not be achieved.

Geographic ranges of naturally occurring forest tree species 

are predicted to shift in response to climate change (Iverson 

et al. 2008). Agroforestry, by contrast, avoids many vectors 

that affect natural reproduction and growth in natural forests. 

Agroforestry systems typically consist of planted trees that 

may be protected from environmental stresses, at least initially, 

through weed and insect control, fertilization, and irrigation. 

A list of tree species suitable for agroforestry in a given region 

consequently may look very different from that of naturally 

occurring forest.

The Chicago Botanic Garden conducted a study in which it 

evaluated effects of a changing climate on the region’s urban 

trees. The study predicts that climate conditions for species 

now flourishing in the Chicago, IL, area will become less suitable after 2020. The predictions were made using the MaxEnt 

(Maximum Entropy Modeling) computer model (Merow et al. 

2013, Phillips et al. 2006), which assesses suitability of species 

under future climate regimes based on bioclimatic parameters 

related to those listed in table B.1.

Climate change will not affect all species in the same way. 

The ranking of different species by their relative suitability 

in the Chicago area will change substantially by mid-century 

(table B.2). Some species will be able to tolerate future 

climates better than others. Among species that are well suited 

under current conditions—pecan, eastern redcedar, and silver 

maple—may continue to thrive under climate conditions 

expected in 2080; however, several other species, such as 

Norway spruce, American linden, and sugar maple, are likely 

to fare poorly in those conditions.

Based on these results, alley cropping-type agroforestry in 

the Chicago area should favor pecan over sugar maple. Both 

species could produce marketable products, but climate conditions within the lifespan of the tree crop may favor only pecan. 

Practices like windbreaks and riparian forest buffers should 

favor silver maple and eastern redcedar over other species for 

environmental benefits over the longer term.

Table B.1. Climate changes and their impact and consequences on tree species. In a changing climate, the success of agroforestry practices depends on planted trees being able to survive and grow under both current and future climate regimes. Changes 

in specific aspects of climate will have specific consequences, often negative, but not always, for tree growth and health. Suitable 

tree species will be able to tolerate such changes in climate over the designed lifespan of the agroforestry practice. 

Change in climate Consequences for tree growth and health

Higher carbon dioxide concentrations; longer growing season Increased growth rate of most species

Higher average winter temperature Winter chilling requirements for flowering and seed germination might not be met

Reduction in cold-associated mortality of insect pests

Higher temperature in early spring Earlier budburst and potentially increased damages by late frosts

Increased frequency of drought Reduced growth rate and increased mortality, especially for newly planted trees

Increased frequency of high or extreme temperature episodes Increased susceptibility to damaging effects of pests

Increased frequency of floods Waterlogging of soils; killing of tree roots

Physical erosion/removal of trees

Source: Adapted from European Environmental Agency: http://www.eea.europa.eu/data-and-maps/figures/impacts-and-consequences-of-climate.
Agroforestry: Enhancing Resiliency in U.S. Agricultural Landscapes Under Changing Conditions 213

Table B.2. Ten tree species are ranked in order of suitability for planting in the Chicago, IL, area under current, 2050, and 2080 

climate scenarios predicted by the Intergovernmental Panel on Climate Change in 2000. All species in the current column are 

suitable if current climate conditions do not change. By 2050, however, the climate will have changed, and some species will be 

favored and others disfavored by those conditions, so the rankings will change. By 2080, climate will have changed beyond the 

tolerance limits of several species (shaded). Agroforestry plantings in the Chicago area that are expected to function beyond 2080 

accordingly should focus on the species that would still be suitable at that time, such as pecan, eastern redcedar, and silver maple. 

Current 2050 2080

Norway spruce (Picea abies) Eastern redcedar Pecan

Silver maple (Acer saccharinum L.) Pecan Eastern redcedar

Northern red oak (Quercus rubra) Hackberry Silver maple

Sugar maple (A. saccharum marshall) White oak Hackberry

Hackberry (Celtis occidentalis) Silver maple Sycamore

American basswood (Tilia americana) Northern red oak White oak

Eastern redcedar (Juniperus virginiana) Sycamore Northern red oak

White oak (Q. alba) Sugar maple Sugar maple

Sycamore (Platanus occidentalis) Norway spruce American basswood

Pecan (Carya illinoinensus) American basswood Norway spruce

Source: Data from Bell (2014).

Literature Cited

Bell, A.C. 2014. Trees for 2050. Glencoe, IL: Chicago 

Botanic Garden. http://www.chicagobotanic.org/plantinfo/

tree_alternatives. (21 October 2016).

Iverson, L.; Prasad, A.M.; Matthews, S. [et al.]. 2008. Estimating potential habitat for 134 eastern US tree species under 

six climate scenarios. Forest Ecology and Management. 254: 

390–406.

Merow, C.; Smith, M.J.; Silander, J.A., Jr. 2013. A practical 

guide to MaxEnt for modeling species’ distributions: what it 

does, and why inputs and settings matter. Ecography. 36(10): 

1058–1069.

Phillips, S.J.; Anderson, R.P.; Schapire, R.E. 2006. Maximum 

entropy modeling of species geographic distributions. 

Ecological Modeling. 190(3–4): 231–259.