USDA United States 

Department of 

Agriculture 

Forest Service 

Arid and Semiarid Land Stewardship: 

A 10-Year Review of 

Rocky Mountain 

Research Station 

General Technical 

Accomplishments and Contributions of the 

Report RMRS-GTR-89 

November 2 001 International Arid Lands Consortium 

Peter F. Ffolliott, Jeffrey 0. Dawson, James T. Fisher, ltshack Moshe, 

Darrell W. DeBoers, Timothy E. Fulbright, John Tracy, 

Abdullah Al Musa, Carter Johnson, and Jim P. M. Chamie 

This file was created by scanning the printed publication.

Errors identified by the software have been corrected;

however, some errors may remain.
Abstract 

Ffolliott, Peter F.;Dawson, Jeffrey 0.; Fisher, James T.; Moshe, Itshack; DeBoers, Darrell 

W.; Fulbright, Timothy. E.; Tracy, John; Al Musa, Abdullah; Johnson, Carter; and Chamie, 

Jim P. M. 2001. Arid and Semiarid Land Stewardship: A 10-Year Review of 

Accomplishments and Contributions of the lnternational Arid Lands Consortium. Gen. 

Tech. Rep. RMRS-GTR-89. Fort Collins, CO: U.S. Department of Agriculture, Forest 

Service, Rocky Mountain Research Station. 74 p. 

The International Arid Lands Consortium (IALC) was established in 1990 to promote 

research, education, and training activities related to the development, management, and 

restoration or reclamation of arid and semiarid lands worldwide. The IALC, a leading 

international organization, supports ecological sustainability and development of arid and 

semiarid lands. Building on a decade of experience, IALC continues to increase the 

knowledge-base for managers by funding research, development, and demonstration 

projects, and special initiatives. The results from the scientific and technical projects 

enhance management and stewardship of arid and semiarid ecosystems for sustainable 

use, while maintaining the integrity of the ecological processes. The publication presents 

a review of the accomplishments and contributions of IALC's science and technical 

programs through a synopsis of the projects and initiatives. We group the projects and 

initiatives into soil and water resources development and conservation, land use and 

reclamation, processes enhancing the management of ecological systems, and inventorying and measurements techniques and monitoring. 

Keywords: Arid and semiarid lands, land use, reclamation, soil and water resources, 

ecological systems, inventorying and monitoring 

Acknowledgment 

This publication was partly supported by funds provided to IALC by the USDA1s Forest 

Service and Cooperative State Research, Education, and Extension Service. Its authors 

are past and present members of IALC's Research and Demonstration Advisory Committee 

and IALC's business manager 

You may order additional copies of this publication by sending 

your mailing information in label form through one of the following 

media. Please send the publication title and number. 

Telephone (970) 498-1 392 

E-mail rschneider@fs.fed.us 

FAX (970) 498-1 396 

Mailing Address Publications Distribution 

Rocky Mountain Research Station 

240 West Prospect Road 

Fort Collins, CO 80526-2098 

Cover Logo of the /nternat/bna/ An'd Lands Consortium 

show/hg the exfenf of arid and sem/brid /ands wor/dwide. 
Arid and Semiarid Land Stewardship: 

A 10-Year Review of 

Accomplishments and Contributions of the 

International Arid Lands Consortium 

The Authors 

Peter F. Ffolliott is a Professor at the School of Renewable Natural Resources, 

University of Arizona, Tucson, AZ. 

Jeffrey 0 Dawson is a Professor at the Department of Natural Resources and 

Environmental Sciences, University of Illinois, Urbana, IL. 

James T. Fisher is a Professor and Head at the Department of Agronomy and 

Horticulture, New Mexico State University, Las Cruces, NM. 

ltshack Moshe is a Deputy Director at the Southern Region, Land Development 

Authority, Gilat DN Negev, Israel. 

Darrell W. DeBoers is a Professor Emeritus at the Department of Agriculture & 

Biosystems Engineering, South Dakota State University, Brookings, SD. 

Timothy. E. Fulbright is a Professor at the Caeser Kleberg Wildlife Research 

Institute, Texas A&M University-Kingsville, Kingville, TX. 

John Tracy is the Executive Director at the Center for Watershed & Environmental 

Sustainability, Desert Research Institute, Reno, NV. 

Abdullah Al Musa is a Professor and Academic Vice President at the Scientific & 

Medical Faculties, University of Jordan, Amman, Jordan. 

Carter Johnson is a Professor at the Department of Horticulture, Forestry, 

Landscape, and Parks, South Dakota State University, Brookings, South Dakota. 

Jim P. M. Chamie is the Managing Director, International Arid Lands Consortium, 

Tucson, Arizona. 
Preface 

As President of the International Arid Lands Consortium (IALC), I am 

pleased to have been part of its first 10 years. This publication, AMand 

Sem/aM Land Sfewardsh@' A 10- Year Re view of Accomp/ishmenfs and 

ContH/;buf/bns of the /nternationa/ ArkI Lands Consortium, is a testament to 

those from different cultures and societies who are working together effectively in the interest of arid and semiarid environments. Scientists affiliated 

with IALC have shown a commendable ability to cooperate on projects and 

initiatives of mutual interest. Readers of this publication are encouraged to 

view this effort as one of ongoing collaboration and achievement. 

Where will the next 10 years lead those involved in the scientific and 

technical programs of IALC? Much remains to be accomplished. We look 

forward to future collaboration with the entire Middle Eastern region and other 

arid and semiarid regions worldwide, as exists with our present partners in the 

Middle East. Water issues will continue to abound, increasing population 

pressures on limited natural resources will continue to grow, and the need to 

forge collaborative initiatives in sustainable economic development will persist. The IALC will continue to play a significant role in addressing these 

issues. 

The Board of Directors is pleased to take this opportunity to recognize 

the diligent efforts of the Research and Demonstration Advisory Committee 

(RADAC) of IALC in preparing this publication. The RADAC is a peer-review 

committee that advises IALC's Board of Directors on funding projects and 

initiatives. I also want to thank the USDA Forest Service, Rocky Mountain 

Research Station for publishing this 10-year review of IALC's scientific and 

technical programs. The IALC's long-standing relationship with the Forest 

Service continues to be productive. The research, development, and demonstration projects and special initiatives discussed in this publication were 

funded largely by the USDA Forest Service and the USDA Cooperative State 

Research, Education, and Extension Service. We gratefully acknowledge the 

continuing support of and dedication to IALC by these organizations. 

Kennith E. Foster 

President, IALC 
Contents 

Chapter I 

Introduction ........................................................................................... 1 

Cooperation and Collaboration ............................................................ 1 

Scientific and Technical Programs ...................................................... 1 

Accomplishments and Contributions ................................................... 2 

Chapter 2 

Soil and Water Resources Development and Conservation ................... 3 

Research and Development Projects .................................................. 3 

Demonstration Projects ....................................................................... 10 

Special Initiative ................................................................................... 16 

Chapter 3 

Land Use and Reclamation ..................................................................... 17 

Research and Development Projects .................................................. 17 

Demonstration Projects ....................................................................... 21 

Special Initiatives ................................................................................. 23 

Chapter 4 

Processes Enhancing the Management of Ecological Systems ............. 27 

Research and Development Projects .................................................. 27 

Demonstration Projects ....................................................................... 39 

Special Initiative ................................................................................... 42 

Chapter 5 

Inventorying and Measurement Techniques and Monitoring .................. 43 

Research and Development Projects .................................................. 43 

Demonstration Project ......................................................................... 49 

Chapter 6 

Synthesis of Accomplishments .............................................................. 51 

Thematic Summaries ........................................................................... 51 

Other Comments ................................................................................. 55 

Chapter 7 

The Future ............................................................................................... 57 

Challenges ........................................................................................... 57 

Options for Meeting the Challenges .................................................... 57 

Chapter 8 

Literature Cited ....................................................................................... 61 

Appendk 

IALC Funded Projects 1993-2000 .......................................................... 71 

Chaper I 

Introduction 

The International Arid Lands Consortium (IALC ) , established in 1990, promotes research, education, and 

training activities related to the development, management, and restoration or reclamation of arid and semiarid lands worldwide, with a focus on the Southwestern 

United States and the Middle East. IALC, a leadlng 

international organization, supports the ecological 

sustainability and development of arid and semiarid 

lands. TALC addresses the pressures on natural resources associated with shihng demographics and public 

expectations and concerns. Areas receiving IALC attention include the reallocation of water from agriculture to urban uses; endangered, threatened, and sensitive 

plant and animal species; and excessive exploitation and 

development of limited natural resources. 

IALC's mission is to help people suffering from 

famine, overpopulation, disease, pollution, and the 

degradation and depletion of natural resources to improve their quality of life and the quality oflife for future 

generations. IALC applies research and development, 

educational and training initiatives, demonstration 

projects, workshops, and technology-transfer activities 

to the development, management, restoration, and 

reclamation of arid and semiarid lands in the United 

States, the Middle East, and elsewhere in the world. 

IALC's member institutions and affiliate members, 

through their ongoing applied research efforts, support 

these activities. 

Cooperation and Collaboration 

IALC is a partnership of organizations dedicated to 

the Consortium's mission. Member institutions are the 

University of Arizona, New Mexico State University, 

the Jewish National Fund, South Dakota State 

University, the University of Illinois, Texas A&M 

University-IGngsville, the Desert Research InstituteUniversity and Community College System of Nevada, 

and Jordan's Higher Council for Science and 

Technology. Egypt's Ministry ofAgriculture and Land 

Reclamation, Under Secretariat for Afforestation is an 

affiliate member. Collaboration with cooperators from 

other institutions, including the USDA Forest Service, 

USDA Cooperative State Research, Education, and 

Extension Service, and similar institutions worldwide, 

is also promoted. Because the sum of resources offered 

by IALC surpasses anything that a single entity could 

offer, the efficient exchange of research, management, 

and technology-transfer mechanisms is enhanced. 

IALC brings people and programs together in diverse areas, such as water resource development, conservation, and management; land-use planning and 

decision makmg; soil resource conservation and management; ecosystem processes; and inventory technology. Thus, IALC provides a broad basis for the 

coordination of activities in arid and semiarid land 

management and research. Funding for IALC, primarily from the Forest Service and Cooperative State 

Research, Education, and Extension Service, ensures 

that management and research experts are efficiently 

and effectively disseminating results. 

Scientific and Technical Programs 

Building on a decade of experience, IALC increases 

the knowledge- base for managers by funding research, 

development, and demonstration projects, and special 

initiatives. The results from the scientific and technical 

programs enhance management and stewardship of 

arid and semiarid ecosystems for sustainable use, while 

maintaining the integrity of the ecological processes. 

One evaluation criterion for proposals submitted to 

IALC is a link between the proposed effort and a 

solution to arid and semiarid land management 
Chapter 7 

problems. IALC supports basic research, but the 

relevance of the research to management problems and 

situations must be clearly stated. The evaluation model 

derives from the United States' land-grant university 

tradition and reflects a commitment to public service at 

a practical level. 

The Consortium's scientific and technical programs 

encourage projects with synergistic interinstitutional 

and international collaboration. Funding research, development, and demonstration projects and special 

initiatives ensures that scientists are conducting relevant research, and that their results are efficiently and 

effectively disseminated. 

Research and Development Projects 

IALC supports research and development projects 

that promote management for sustainable forests and 

woodlands, shru blands, grasslands, and agroforestry 

systems on arid and semiarid lands. These ecological 

systems include humans as biophysical and sociocultural components of ecosystems. A Board of Directors 

determines IALC's policies including research and 

development subject areas that are eligible for support. 

Traditionally, these areas are land reclamation, land use, 

soil and water resources development, soil and water 

conservation, water quality, inventory technology, ecosystem processes supporting sustainable management, 

enhancement of sustainable management of ecosystems, and the socioeconomic dimensions of these areas. 

Many projects supported by IALC in its 10-year 

history concern the critical issue of biodiversity. Understanding the levels and scales of arid and semiarid land 

biodiversity continues to challenge managers attempting to sustain ecosystem functions, optimize the wellbeing of plant and animal species, and maintain niches 

for threatened, endangered, and sensitive species 

(Dawson et al. 1999, forthcoming). IALC also supports research and development that promote improved management of crucial soil and water resources 

in natural ecosystems and agronomic systems (Ffolliott 

et al. 2000). The Consortium has funded fifty research 

and development projects since 1993-when funding 

first became available. Some projects supported by 

IALC are completed, others are ongoing, while others 

have only recently been initiated. 

Demonstration Projects 

IALC's demonstration projects represent application of research and development results to the management of sustainable ecological systems. 

Demonstration projects must clearly identify the benefits derived and people served and link the available 

laowledge to those that are responsible for planning, 

management, and decision making at all levels of society. IALC-supported demonstration projects are sufficient in temporal and spatial scales to enhance the 

acceptance and application of the benefits obtained. It 

is also critical that the information or technology 

demonstrated or the educational goal sought is relevant 

to those living in the region. 

Specific conditions that demonstration projects must 

meet to obtain IALC support are outlined elsewhere 

(Ffolliott et al. 1998). Since 1993, IALC has fimded 16 

demonstration projects, at varying stages ofcompletion. 

Special Initiatives 

IALC special initiatives include workshops, conferences, We bsites, training courses, and other technologytransfer activities. IALC actively participates with other 

organizations in supporting these initiatives. Members of 

the Board of Directors or the Research and Demonstration Advisory Committee propose special initiatives to 

complement IALC's scientific and techcal programs. 

Accomplishments and Contributions 

To illustrate the historical scope and breadth of 

IALC's scientific and technical programs, research, 

development, and demonstration projects and special 

initiatives funded by IALC are listed in the appendix. A 

review of accomplishments and contributions of IALC 

to improved management and land stewardship of arid 

and semiarid lands is presented in the publication through 

a synopsis of the projects and initiatives. We group the 

projects and initiatives into the following categories: 

soil and water resources development and conservation, 

land use and reclamation, processes enhancing the 

management of ecological systems, and inventolying 

and measurements techniques and monitoring. 
Soil and Water Resources 

Development and Conservation 

Research and Development Projects 

Mitigating Effects of 

Sealing and Crusting of Soils 

Sealing and crusting of soil surfaces is a major concern in arid and semiarid environments. Sealing reduces 

infiltration of water and inhibits the emergence and 

survival of seedlings. Agricultural crops must often be 

replanted due to failed emergence in sealed soils 

(Gardiner et al. 1996). Preventing the formation of 

sealing or controlling sealing strength is important to 

achieve a greater efficiency ofwater use, seedling emergence and survival, and agricultural crop production. 

One way to mitigate sealing is to maintain a wet soil 

surface by frequently irrigating. However, the approach 

is expensive and wasteful. Another way to improve soil 

structure and aggregate stability is to add soil conditioners, such as polyacrylarnides, to the soil surface. An 

IALC study hypothesized that polyacrylarnides applied 

during crop planting will reduce soil sealing and improve water infiltration and seedling emergence. It was 

further hypothesized, in a companion IALC study, that 

gypsum will enhance the beneficial effects of 

polyacrylamides. 

Studies 

Greenhouse and field studies in Texas and Israel 

continue to evaluate the effectiveness ofpolyacrylamides 

and gypsum combinations on soil properties and the 

emergence and survival of agricultural crops (Levy et al. 

1995, Gardiner and Carr 1999, Rapp et al. 2000). The 

influence of soil texture and the composition of 

exchangeable cations on seedling emergence and 

morphological characteristics were examined in 

greenhouse studies. While in ongoing field studies, 

gypsum is broadcast and polyacrylamides are applied in 

strips above the seeds at the time of planting. The 

emergence and survival of the seedlings, overall crop 

yields, and infiltration rates in the seeded rows were 

measured. 

Results indicate that polyacrylarnides reduce soilcrust strengths and improve hydraulic conductivity of 

Texas soils, with high sand and low silt contents in the 

greenhouse and field. Infiltration rates are doubled in 

sandy-clay-loam soil in the field (Gardiner and Carr 

1998, Gardiner et al., 1998, Gardiner et al. 199913). 

Repeated applications of polyacrylarnides improve the 

persistence of these effects. The cactus extracts containing polysaccharides and polyacrylamides also improve 

the infiltration rate in soils, with high sand and low silt 

contents (Gardiner et al. 1999a). Other results indicate 

that applications of polyacrylarnides increased evaporation from soil surfaces in an Israeli greenhouse study 

(Rapp et al. 2000). Emergence of shallowly seeded 

plant crops in Texas was usually unaffected by 

polyacrylarnides. Applications of polyacrylarnides and 

gypsum increased the emergence rate of onions in an 

Israeli field study. 

Polyacrylamide applications reduced soil-crust 

strength, improved infiltration, and decreased erosion 

in many soils. However, seedling emergence in response to polyacrylamides and gypsum was inconsistent-emergence and survival of some seeded plant 

crops benefitted, there was little effect on other seeded 

plant crops, while still others were adversely affected. 
Applying polyacrylamides with or without gypsum only the oxidation state of transition metals in phyllosilicate 

to improve the emergence of small seedlings in crusted clay materials and Fe and Mn oxides, which alter the 

soils is not recommended (Gardiner and Carr 1999). nature, composition, and chemical behavior of soilDefining interactions among soil characteristics, infil- mineral surfaces and result in an active chemical 

tration rates, seedling emergence, and other factors environment at the mineral-liquid interface, were tested 

needs further investigation. in a study. Surface chemical reactions related to Fe and 

Mn were measured in the laboratory and field 

Soil Contamination by Toxic Substances 

Application of sewage sludge, heavy metals, and 

other potentially toxic substances to soil systems is 

common in many arid and semiarid countries. However, these applications present a risk to human health 

and the environment. The behavior of these substances 

is determined by their chemical reactions with inherent 

soil constituents. The most reactive substances are 

phyllosilicate clay materials and clay-sized iron (Fe) and 

manganese (Mn) oxides (Scott and Arnonette 1988, 

Stuclu 1988, Stuclu and Lear 1989). Occurrences of 

the chemical reactions are attributed to their high 

specific-surface areas, cation exchange capacities, amphoteric surfaces, and oxidation reductions. Oxidation 

can affect soil-mineral properties. 

Characteristics of soil-mineral properties vary in space 

and time because of seasonal or other cyclic oxidationreduction processes, such as wetting and drying and 

warming and cooling, which involve microbial activities 

and alter oxygen supplies. Adding oxidation-reductionactive metals or organic compounds in sewage sludge 

that flows into a soil system promotes oxidationreduction reactions with transition metals within the 

soil minerals. The oxidation-reduction reactions can 

alter the properties and behavior of the metal and 

organic compounds and the minerals themselves (Foth 

1990). Consequently, these reactions are important to 

long-term soil quality and could modify the behavior of 

pollutants in the soil environment. 

investigation. Oxidation states and chemical 

compositions, cation exchange capacities, acidity 

swelling pressures, and absorption properties were also 

determined. A protocol to continuously measure the 

potential oxidation-reduction changes in a minimally 

dsturbed field site that receives reclaimed sewage effluent 

or groundwater was also devised. 

The study is increasing the available information 

about soil-clay properties and behavior under changing 

oxidation-reduction potentials. Particularly important 

is that the effects of oxidation on clay-organic surface 

interactions, the hydrophobic characteristics of these 

surfaces, and the clay-water surface interactions are 

better understood. This understanding improves our 

appreciation of the underlying mechanisms and reactions, which determine the behavior of water, organic 

material, nutrient irons, heavy metals, and other harmful substances in soil, when oxidation-reduction- active 

material is added. 

The study is extending our lmowledge of the physicalchemical processes that lead to the contamination of 

soil systems from the disposition ofpotentially hazardous 

substances, such as sewage sludge and heavy metals, 

into soils. These substances are influenced by their 

interactions with the constituents of the soil system. 

Phyllosilicate clay minerals and clay-sized Fe and Mn 

oxides play crucial roles in these interactions. High 

specific surface area, large cation exchange capacity and 

amphoteric surfaces, and active oxidation-reduction 

Studies properties characterize the soil constituents. Applications 

ofsewage sludge promote oxidation-reduction processes 

IALC continues to support studies at the University in soils by providing ox~dation-reduction-active metals 

of Illinois and in Israel that characterize the surface, or organic colnpounds and surface water. This causes 

colloidal properties, and con1position of Fe- and Mn- the alteration of soil properties and behavior of metal 

bearing soil minerals during and after oxidation- and organic compounds, which results in long-term 

reduction reactions, which occur when sewage sludge effects on soil quality. Results from the study will help 

and other contaminated water is applied. Changes in land managers prescribe improved land-use practices 
Soil and Water Resources Development and Conservation 

and conservation measures through maintenance of 

non-contaminated and productive soils found in arid 

and semiarid environments. 

Selenium Pollution of 

Subsurface Drainage Systems 

Subsurface drainage water containing pollutants is a 

concern to planners and managers ofirrigation projects, 

agriculturalists, and people living downstream of irrigated lands. Selenium, salinity, and sodium concentrations are potential pollutants of particular concern 

because of their long-term impact on water quality 

(Summers and Anderson 1986, National Research 

Council 19 89). However, baseline information on the 

status of soil selenium and related chemicals before 

implen~entation of proposed irrigation projects is often 

unavailable. The IALC study was conducted to provide 

this information for an irrigation project in southcentral South Dakota and then to use the information 

to estimate potential selenium and other chemicals 

discharges from the project area. 

Selenium, salinity, and sodium concentrations were 

measured to assess the potential impacts of these soil 

constituents on the quality of return-water flows from 

the proposed Lake Andres-Wagner Irrigation Project. 

Analyses of soil samples collected at specified depths 

and intervals along a 30-km transect indicated few 

general trends or consistent spatial structures in magnitudes of the chemical constituents sampled (DeBoer et 

al. 1994). A transfer fiulction was developed to simulate the discharge of solutes, such as selenium, from a 

subsurface drain line. The function generated simulation results within a fraction of the time required for a 

comparable solution based on a classical flow technique 

(DeBoer and Warriclc 1994, Warriclc et al. 19%). The 

basic assumption of these simulation results was that 

either piston- or bulk-water flows control movements 

of selenium or other solute to the drain line. Influences 

of diffkion, dispersion, and chemical reactions in the 

soil must be defined before acceptable estimates of 

solute discharges from subsurface drainage systems are 

possible. 

The analytical procedures developed in the study are 

important to planners and managers of proposed irrigation projects. From an environmental perspective, it is 

critical that we can estimate the magnitudes of selenium 

concentrations and other pollutants in drainage water 

from operational areas of irrigation projects. From a 

site-specific standroint, the applied results of these 

analytical procedures are valuable to the proposed 

South Dakota Lake Andes-Wagner Irrigation Project. 

Atmospheric Carbon Dioxide 

Sequestration and the Global-Carbon Cycle 

Carbon dioxide (CO,) in the earth's atmosphere 

continues to rise at alarming rates (Schlesinger 1997). 

While the consequences of the rise are uncertain, the 

possibility of C0,-induced global warming (greenhouse 

effect) is stimulating investigations ofthe global-carbon 

cycle and land management practices to mitigate 

effects (Schlesinger 1997, La1 et al. 1998). Soil-organic 

carbon is the largest terrestrial pool of carbon and soilinorganic carbon (soil carbonate)-common in arid 

and semiarid soils-is the second largest terrestrial 

pool. More is lmown about the soil-organic-carbon 

pool than the soil-carbonate poon. Information that is 

missing about the soil-carbonate pool is the amount of 

CaCO, (calcium carbonate) sequestered in atmospheric 

CO,. Unfortunately, data bases of total soil carbonates 

that contain primary, lithogenic, and atmogenic 

subgroups are insufficient. The latter soil carbonate 

subgroup is from the weathering of Ca-silicates and 

HCO, (hydrogen carbonate) and root and microbial 

respiration. Only atmogenic carbonate is a sink for 

atmospheric CO,. 

The IALC study was initiated to learn about the 

atmospheric CO, sequestered by soil. Optical, x-ray 

mineralogy, and other methodologies are being used to 

vest the hypothesis that calcium isotopic signatures can 

separate primary and lithogenic CaCO, from atmogenic 

CaCO. and primary CaCO, can be separated from 

lithogenic and atmogenic CaCO,. Relative proportions 

of the soil carbonate subgroups are being determined 
Chapter 2 

for the soils of southern New Mexico and northeastern 

Jordan. These soils are well-suited for developing the 

necessary partitioning techniques because most of the 

soil-forming factors can be held constant by researchers 

to determine the source of calcium in CaC0,-the 

exception is soil-parent material. Researchers can also 

hold soil-forming factors, other than climate and 

vegetation, constant to determine how much carbon in 

CaCO, is from C, plants, C, plants and the limestone 

parent material. 

The study addresses the global carbon cycle 

information gap-the extent that arid and semiarid 

soils can sequester C02 from the atmosphere into the 

calcium-carbonate system. Although the carbon pools 

in these environments are large, the fluxes to and from 

the atmosphere are poorly understood. In the future, 

these soils could be managed to sequester C02 and 

mitigate impacts of the greenhouse effect, which could 

lead to carbon credits for these ecosystem managers. 

However, CO, sequestered by soil CaCO, must be 

quantified, and processes that lead to its formation fully 

known. 

Function of Active Soil Organic Matter in 

Determining Soil Quality and 

Potentials for Land Reclamation 

Active soil-organic matter is the portion of the soil 

body that is responsible for the formation of soil 

aggregates. Soil aggregation improves soil structure by 

reducing erosion, decreasing bulk density, and improving soil- biological functions by increasing porosity, 

aeration, and water movement. An improved understanding of the function of organic matter fractions in 

the sandy soils of arid and semiarid regions is the 

purpose of the IALC study. We hope to use knowledge 

of these fractions as an indicator of soil quality, which 

will enhance the ability to reclaim degraded arid lands. 

Managing these ecosystems to stabilize soils would 

improve their quality by promoting soil aggregation. 

Soil aggregation would be accomplished by comparing 

spatial patterns in soil-aggregate stability in perennial 

grassland and shrubland ecosystems and relating these 

patterns to vegetation; identifying soil-organic-matter 

fractions-loose, light, particulate, humin, and acid 

hydrolyzable carbohydrates-associated with soil 

macroaggregation; and identifying the probable sources 

of these fractions. 

Relationships between plant cover and the spatial 

variability in aggregate stability on perennial grassland 

and degraded mesquite (Prosopis spp. ) shrubland sites 

are being established on the Jornada Experimental 

Range in southern New Mexico. General relationships 

among macroaggregate stability and location, plant 

species, and surface cover are being evaluated, while 

specific relationships involving aggregate stability, soilorganic-matter fractions, and plant species are being 

quantified for sites in perennial grass-shrubland transitions on sandy loam soil. At each study site, soils have 

been sampled at 3 depths beneath the shrub canopy and 

at a paired location in the adjacent bare inter-space for 

each of 5 perennial plant species. Soil-organic-matter 

fractions are determined for whole soil and stable 

macroaggregates. Fungal hyphal and cyanobacterial 

length density are also being analyzed, and the texture 

of all samples and iron oxide and carbonate contents of 

appropriate composites determined. 

Preliminary results indicate that aggregate stability is 

lowest in the bare inter-spaces in all communities 

sampled and at all depths. A high temporal variability in 

aggregate stability, with higher stability occurring after 

the rainy season also exits. Aggregate stability is lower 

and there is increased spatial variability in soils that are 

frequently and intensely disturbed independent of their 

vegetative cover and composition. Glornalin and total 

protein are higher under mesquite shrublands, lower 

under grasses, and still lower in bare inter-spaces. The 

correlation is highest between easily extractable protein 

and total aggregate stability and lowest between sandfree aggregate stability and glomalin. Analyzing the 

data to completely defined these relationships and identi@ 

possible arid land reclamation measures continues. 

Soil-organic matter plays a key role in stabilizing 

sandy soils in arid and semiarid regions. Studies in other 

ecosystems have shown that the contribution of soilorganic matter to soil structure depends largely on its 
Soil and Water Resources Development and Conservation 

The Jornada Experimental Range is representative of the sensitive ecosystems in the 

Chihuahuan Desert and a site of several efforts in the IALC scientific and technical programs. 
Chapter 2 

con~position and distribution (Dutartre et al. 1993, 

Dalal and Bridge 1995). Results from the above study 

will help identify the key biotic and physical resources 

to manage to promote soil aggregation, optimize soil 

stability and productivity, and reduce the possibility of 

land degradation. 

Water Harvesting and 

Treated Wastewater for Irrigation in 

Resources Development and Conservation 

Many methods continue to be used to develop water 

supplies for people in the arid and semiarid regions. 

Irrigation with saline water, reuse of irrigation and 

treated wastewater, and water harvesting are examples. 

Without a permanent water source, a water supply for 

irrigation might be obtained through water-harvesting 

methods. Water harvesting involves collection and 

storage of the intermittent rainfall runoff until the 

collected water can be used beneficially. A distribution 

system is also needed to use the stored water for 

irrigation (Renner and Fraiser 1995a, 199 5 b, Brooks et 

al. 1997). Water-harvesting-used by people in the 

Negev Desert more than 4,000 years ago-continues 

to be used to establish trees and shrubs in plantations, 

growing food and forage crops, and watering livestock 

and wildlife on arid and semiarid lands. While water 

harvesting is ancient technology, people continue to 

explore ways to improve on the basic methods. 

Studies 

Limans (small earthen dams) were constructed for 

the past 50 years across ephemeral waterways of the 

Negev Desert to collect rainfall runoff. Trees and other 

agricultural crops are planted in the limans to capitalize 

on the water collected behind the dams. However, 

limans are closed hydrologic systems that accumulate 

sediments and dissolved salts. IALC supported a study 

to determine whether the accumulated salt deposits in 

the limans were significant enough to cause soil salinization and, if so, adversely affect afforestation efforts. 

The levels of salinization in soil profiles were described 

from limans representing a range of physiographic and 

climatic conditions in the Negev Desert. Soil samples 

were also obtained inside and outside the immediate 

area of the limans to analyze soil properties. R~moff 

water was collected upstream of the dams to estimate 

rates of salt inputs to the limans. 

Despite relatively high salt inputs, analysis of these 

measurements fded to support the hypothesis that limans 

suffer from salt accuinulations and consequent soil 

salinization. Salinity inside the limans was lower than in 

control trenches. Because the limans had been established in relatively leached alluvial flood plains, water 

infiltration and the accompanying leaching have been 

enhanced by tree roots and the sandy and gravel layers 

in the catchments. It was concluded that afforestation 

efforts with this low level of technology can be successful in establishing small groves of trees in the Negev. 

Water harvesting and using treated wastewater (effluent) may increase water supplies to grow trees and 

crops in arid and semiarid regions (Stewart and Flinn 

1984, Hopmans et al. 1990, Karpiscak et al. 1996). 

Researchers in an IALC study are evaluating the possibility of successf~dly growing trees by irrigating them 

with combinations of potable water, treated wastewater, and harvested rainwater (IZarpiscak 1999, 

Karpiscak and Gottfried 1998,2000). The study is also 

attempting to determine if trees take up harmhl constituents in the treated wastewater or if there are any 

adverse impacts to soil irrigated with effluent. 

Plantings of velvet ash (Fmxinus velutina), black 

willow (Salix n;Ora), Freemont cottonwood (Populus 

fremontii), eucalyptus (Eucalyptus camaldulensis), and 

Model1 pine (Pinus elderica) in Arizona and Israel have 

been irrigated with potable water, treated wastewater, 

and harvested rainwater in amounts adjusted to account for seasonal transpirational losses of the trees. 

Survival and initial growth were monitored, nutrient 

uptake in leaves and stem tissue was assessed, and the 

chemical properties of the treated wastewater and the 

concentrations of soil minerals were analyzed. Initial 

findings indicate that, in comparison to irrigating with 

potable water, the survival and growth of some trees 

species were greater when irrigated with wastewater 

combined with water harvesting ( ICarpiscalz 1999, 

IZarpiscak and Gottfried 1998,2000). Measurement of 

total biomass of the surviving trees remains to be done. 

The feasibility of harvesting water for storage in the 

shallow aquifers of the eastern Badia of Jordan (Dutton 

et al. 1998) is being investigated in another IALC 
Soil and Water Resources Development and Conservation 

Trees planted in a liman constructed in the Negev Desert to collect and store intermittent rainfall runoff 

behind the small earthen dam for survival and growth of these trees. 
Chapter 2 

study. Although it is too early to report on the results 

of the study, study findings should improve the available information on hydrometeorological, hydrologic, 

and geochemical factors. These factors are expected to 

determine whether water harvesting is a feasible approach to mitigating the acute water shortages in 

Jordan and other countries that suffer from long-term 

water deficits. 

/mp/ications 

Water harvesting offers a method of effectively 

developing the scarce water resources in arid and semiarid 

regions. In contrast to the development of finite 

groundwater resources, water harvesting uses the limited 

rainfall that occurs throughout the year (Renner and 

Fraiser 1995a, Brooks et al. 1997). Additionally, water 

harvesting is an inexpensive way to supply water to the 

resources and rural people who are removed from largescale water development projects. Water harvesting is not 

a panacea-the uncertainties of rainfall, new management 

slulls, and an efficient design must be considered. 

Nevertheless, IALC studies will continue to further 

the technology necessary to apply water harvesting 

methods to growing trees and crops and storing water 

for livestock use and domestic needs. There are also 

advantages of using treated wastewater rather than 

potable water when irrigating some tree species. However, resolution of the possible health problems associated with wastewater irrigation is necessary before 

widespread applications of effluent are possible. Potential contamination of soils and plants, effluents polluting surface-water-delivery systems, and wastewater 

infiltrating to groundwater aquifers must also be addressed. Selecting trees and crops that wastewater least 

affects, choosing the appropriate irrigation techniquelikely water harvesting-and adding decontaminates to 

the wastewater are also necessary. 

Demonstration Projects 

Sustaining Groundwater Quality 

Through Management of Nitrogen Fertilizers 

There is increasing concern about the possible 

contamination of groundwater resources from nitrogen 

fertilizers applied to agricultural lands. For example, 

groundwater contamination by nitrate-nitrogen that is 

leaching through soils is becoming a serious problem in 

the irrigated Mesilla Valley of southern New Mexico. 

The large amounts ofnitrogen fertilizer that agricultural 

producers are applying to onion, lettuce, chile, and 

other shallow-rooted crops have probably resulted in 

the greatest contamination (Lemblte and Thorone 

1980, Schepers et al. 1991). 

However, only limited information on the mitigation of nitrate-nitrogen leaching to groundwater levels 

has been available to farmers. Therefore, IALC supported a demonstration project to show agricultural 

producers in southern New Mexico that they could use 

a known chloride- tracer technology for efficient nitrogen fertilization management. Using this knowledge, 

producers could then reduce nitrogen concentrations 

in the groundwater beneath their agricultural fields. 

Demonstration 

Farmers in irrigated portions of the Mesilla Valley 

participated in the demonstration project based on 

their farm management practices, and the liltelihood 

that they would use chloride in irrigation water as a 

tracer to monitor their nitrogen fertilization management (Al- Jamal et al. 1998). Crop samples were talten 

at each participating farm to determine baseline crop 

nitrogen-to-chloride ratios and nitrogen fertilizer application efficiencies. After the chloride tracer was 

added to irrigation water, water and soil samples were 

talten below the irrigated field and the nitrogen-tochloride ratios and nitrogen fertilizer application efficiencies were again determined. A user-friendly 

spreadsheet was made available to the farmers to help 

illustrate the observed efficiencies of their nitrogen 

fertilizer applications. Whether the farmers continued 

to apply the chloride tracer technology assessed success 

or failure of the demonstration effort. 

While the use of chloride tracers to evaluate nitrogen 

fertilizer application efficiencies is a proven research 

technology, it had never been applied at the farmmanagement level. However, none of the participating 

farmers chose to continue the use of the technology. 

Several felt that the cost of applying the chloride tracer 
Soil and Water Resources Development and Conservation 

could outweigh the technology's benefits. Also, most 

ofthem believed that the problem ofincreased nitrogen 

concentrations in groundwater aquifers is a societal 

problem. Therefore, they felt that reducing their 

nitrogen fertilizer concentrations would give them only 

marginal benefits. Additionally, the farmers thought 

that the technology might cause some farmers to apply 

too little nitrogen fertilizer, which would reduce crop 

yields. These problems show that technology can be a 

sociological-psychological issue when trying to 

introduce it as an operational management tool. 

Use of Wastewater to Grow Trees for Profit 

Improper treatment and disposal of human wastes 

affect many communities in arid and semiarid lands by 

causing environmental degradation and declining public 

health. The situation exists in many small communities 

along the United States and Mexico border. The people 

in the area need effective wastewater treatment systems 

to reduce contaminants and a method of recycling the 

nutrients contained in their wastewater. One 

technologically viable solution is to apply wastewater to 

the landscape to grow commercially valuable shortrotation trees (Sopper et al. 1982, Page et al. 1983, 

Cole et al. 1986). This low-cost approach can safely 

recycle sludge and wastewater, while protecting the 

environment and providmg opportunities for enhanced 

economic development. 

An IALC demonstration project is exploring the 

feasibility of implementing the above technology in 

Ojinaga, Chihuahua, Mexico. The municipality is typical of many small- to medium-sized farming-based and 

economically-disadvantaged border communities. Currently, Ojinaga pipes its sewage into an anaerobic 

lagoon adjacent to the Rio Grande fiver where the 

solids separate from the waste stream. Those living in 

Ojinaga understand the need to mitigate the unhealthy 

situation. The demonstration project is intended to 

promote heightened environmental awareness, while 

solving local problems of wastewater treatment and 

disposal by using wastewater to produce fast-growing 

pulpwood trees. 

Specialists in water and soil management, irrigation 

engineering, forestry, small business development, and 

community planning from the United States and Mexico 

are cooperating in 3 outreach efforts. One effort, 

targeted to school teachers, involves preparation of 

educational materials on environmental awareness and 

responsible management of the ecosystems within the 

fio Grande fiver basin. Another effort focuses on 

expositions for the local farming community, school 

children and their families, neighboring communities, 

and representatives from local and state agencies. The 

exposition includes visual displays, tours of the project 

site, environmental awareness workshops, and literature on wastewater treatment-tree production systems 

and related small business development. A third effort 

is a conference to help local farmers determine if a 

cooperative pulpwood plantation irrigated by Ojinaja's 

wastewater is a viable economic option. The conference 

focuses on the advantages of community-driven cooperatives (Stanford 1994), opportunities for subsiding 

crop production, and community-shared financial and 

in-kind risk and equity. 

Benefits 

Increased public awareness about how to dispose of 

wastewater using environmentally sound and 

economically beneficial methods and learning about 

how to profit from growing pulpwood tree species are 

the benefits of the above demonstration project. 

Through binational educational and training programs 

and public relations, these benefits are shared with the 

people of Ojinaga and other small- to medium-sized 

communities along the United States and Mexico 

border. Ifsuccessful, the project can serve as a model for 

wastewater treatment and disposal and the economic 

development of other local communities. 

Controlling Desertification 

Through Savannization 

Vast land areas in arid and semiarid regions are 

becoming desert-like because of over-exploitation of 

natural resources-a processes often exacerbated by 

climatic changes (Anaya-Garduno et al. 1994, Mouat 

and Hutchinson 1995). Increases in soil erosion and 
decreases in land productivity and the diversity of plant 

and animal species characterize desertification. However, 

ecologically-sound management of lands threatened by 

desertification can stop and, sometimes, even reverse 

the desertification process. The Land Development 

Authority initiated the Savannization Project in 1986 

to control desertification in Israel's northern Negev 

Desert (Sachs and Moshe 1999). 

The focus of the project is to create patches of high 

productivity on desert landscapes that have low productivity by planting trees. Collecting surface water 

from the undisturbed surrounding area enriches the 

soil, which benefits the patches. By applying the water 

harvesting technique, further soil erosion is prevented 

and the collected runoff is used to irrigate the planted 

trees. The Savannization Project has successfully increased the biological productivity and diversity of land 

uses in the Negev and has helped to develop management practices of forester-sustained land uses. To transfer the knowledge from the Savannization Project to 

others, TALC has supported demonstration projects in 

Israel and in northern Chile. These projects teach the 

principles of savannization by demonstrating how understanding the ecological structure and function of 

desert landscapes can help people restore degraded 

areas that desertification threatens. 

Demons tra tbns 

Demonstration sites have been established at a research station in the northen Negev Desert to illustrate 

how ecological understanding is linked to savannization. 

One site shows the relationship between landscape 

components and surface runoff regimes. Here, participants conduct experiments in small-scale irrigation to 

determine and discuss the influence of shrub-covered 

and inter-shrub (crust) patches on runoff generation. A 

tour of the ongoing studies at the research station is 

another activity in the demonstration. Studies about 

the structure and function of small-scale landscape 

units, the effects of changes in patchiness on natural 

resources and species richness, and the responses of 

herbaceous plants and other natural resources to patch 

disturbances are visited. 

Participants construct conceptual models of the 

processes and effects of savannization. They evaluate 

the reliability and reality of the relationships presented 

the models and explore the effects of grazing livestock, 

cutting trees, building fences, and other human-induced 

activities on ecological productivity and diversity. To 

conclude their visit, participants travel to a site away 

fi-om the research station where the Land Development 

Authority is conducting savannization and other 

ecosystem- based management. Here, the participants 

are introduced to the management rationale of the 

models that they developed earlier. The historical and 

often incorrect uses of the ecosystem resources that 

have created excessive soil erosion and decreased plant 

and animal productivity and diversity are also explained. 

A similar demonstration effort has been recently 

initiated in northern Chile. The principles and practices 

demonstrated to students, local farmers, and other 

clientele are based largely on Israel and Chilean 

techniques. Demonstration modules show the nature 

of biological productivity, water movement, and plant 

and animal diversity in shrub and inter-shrub patches, 

the hnctional relationships between surface runoff and 

the 2 patch types, and how ecologically sound 

management practices affect water harvesting and tree 

growth. 

Benefits 

A better understanding of the processes that limit the 

production and diversity of plants and animals on these 

landscapes is needed for effective ecosystem resource 

management. Demonstration projects on savannization 

show that it is not the lack of water, soil, and nutrients 

but the availability of these resources to plants, animals 

and other biotic elements that affect the production 

and diversity of desert land (Shachak et al. 1998,1999). 

The existing water, soil, and nutrient-resource base that 

biotic elements in the ecosystem do not use because 

they escape from the ecosystem is demonstrated. However, through savannization and similar efforts to create 

patches of high productivity on arid and semiarid lands 

of low productivity, the existing water, soil, and nutrients from the undisturbed surrounding areas are effectively captured to grow trees or benefit other biotic 

elements. The net effect is an increase in plant and 

animal productivity and diversity and a reversal of the 

processes leading to desertification. 
Soil and Water Resources Development and Conservation 13 

Controlling desertification in the Negev Desert through savannization efforts and other 

tree planting activities has been successful in many instances. 
Chapter 2 

Water Conservation by Drip Irrigation 

The effectiveness of drip irrigation in crop rotation 

schemes, including alfalfa, is the focus of this recently 

initiated IALC demonstration project in southern New 

Mexico. Traditional methods of irrigating agricultural 

crops in the Southwestern United States include 

inefficient flood and sprinkler systems. Effective 

irrigation methods and water conservation measures 

are needed for irrigated agriculture to remain profitable 

and environmentally acceptable. Recent innovations in 

drip irrigation technologies, such as improved driptape designs, have enhanced the usefulness of this lowwater agricultural irrigation system (Bucks et al. 198 8, 

Powell and Wright 1993, Camp et al. 1995, 2000, 

Hanson et al. 2000). Demonstrating the benefits, 

costs, and proper agronomic management practices of 

subsurface drip irrigation are key to promoting longterm water savings. 

Demonstration 

A drip irrigation system has been installed at New 

Mexico State University's Agricultural Science Center 

to illustrate subsurface drip irrigation practices. All 

system inputs (labor, water, and maintenance) and 

outputs (alfalfa and rotational-row crop production 

levels) are being monitored for future water conservation and the economic analysis of this alternative irrigation practice. An enterprise budget for alfalfa production 

using drip irrigation is generated to help encourage 

acceptance of the technology and to indicate the changes 

in farm management required to sustain alfalfa production in the common crop rotations schemes of the 

region. Workshops and study tours are also being 

conducted. 

Benefits 

Alfalfa is produced on most of the land irrigated for 

agricultural production in New Mexico-a state where 

water conservation is important. The IALC demonstration project shows how water savings and economic 

benefits can be obtained by using buried drip irrigation 

systems rather than flood or sprinkler irrigation. Reducing the water needed for profitable agricultural production should help to restore in-stream flows and improve 

groundwater availability. 

Improving Water Quality and Environmental 

Conditions Using Integrated Pest Management 

An effective way to control plant pests is to use a 

combination of chemical, biological, and mechanical 

control methods-known as integrated pest management (IPM). Implementing IPM practices often prevents the adverse impacts from the continuous use of 

pesticides, eliminates or reduces resistance to particular 

pesticides, and provides a backup control system if 

other methods fail. Building on a training program in 

the Middle East, researchers from the University of 

Illinois began an IALC demonstration project in 1994 

to educate farmers on the West Bank and Gaza about 

the detrimental effects of excessive pesticide use. Pesticides have caused deteriorating water quality, environmental degradation, and health problems for farming 

communities in these fragile areas. 

Demonstration 

A survey was used to obtain information about the 

farmers, their farms and households, major constraints 

to agricultural production, farm management practices, 

decision making within the households, and the 

technology used to produce greenhouse and field 

crops. Attention was also given to pesticides use, farmer 

knowledge of pests, methods of pest control for crop 

management systems, exposure of farmers to 

pesticides, and exposure effects. The surveyors found 

excessive pesticide application, which confirmed earlier 

research findings and observations. Farmers determined 

pesticide use through trial and error applications that 

were based on untested information provided by dealers, 

other farmers, and nongovernmental organizations. 

In response to the heavy use of pesticides, researchers 

from the University of Illinois proposed a farmer 

education program focusing on safe and effective 

pesticide use and initiation of IPM technology. The 

purpose of the program was to teach farmers how to 

implement effective IPM programs, which would lower 

their input costs while sustaining agricultural diversity, 

improving water quality, slowing environmental 

degradation, and reducing health risks. The farmers will 

need effective follow up from research and extension 

programs to adopt fully and continue to use the 

information. 
Soil and Water Resources Development and Conservation 

Benefits 

Farmers on the West Bank and Gaza should attain 

higher water quality, less environmental degradation, 

sustainable agricultural crop production, improved 

personal health, and increases in incomes by adopting 

the pest control methods offered by IPM techniques. 

Improved lznowledge of IPM technology will also 

enable efficient use of limited land, water, and other 

natural resources by farmers, agricultural managers, 

and other stalzeholders. 

Transferring Technology to Improve 

Soil Management on Erodible Lands 

No-till agriculture can reduce surface-water runoff 

and soil loss from wind and water on highly erodible 

soils. Carefully planned no-till systems also increase 

farm profitability (Lamb et al. 1985, Reicoslzy and 

Lindstrom 1993, Ismail et al. 1994). Annually, up to 

145,000 ha of highly erodible landscapes in central 

South Dakota are converted from grasslands to agricultural croplands because of expiring Conservation Reserve Program (CRP) contracts with the U.S. 

Department of Agriculture. Farmers need information 

about no-till agriculture to minimize soil and water 

degradation for successful land conversion. The information is transferred to the farmers through on-farm 

demonstration activities supported by TALC. 

The advantages and challenges of no-till agriculture 

are transferred to farmers through on-farm 

demonstrations, sharing experiences of no-till farmers, 

and relevant research studies. Farmer-led discussion 

groups provide a forum to discuss no-till agriculture. 

Training materials have been developed for extension 

agents, agronomic consultants, and others involved in 

no-till technology transfer. Workshops for 

technology-transfer specialists focus on practical 

applications of no-till technology to farm enterprises. 

Teams of experienced researchers, practitioners, and 

technology-transfer specialists have organized and 

conducted these demonstration efforts for the general 

farm audience. 

Effective and responsive methods of transferring 

information about soil management technology on 

highly erodible lands are enhanced through the 

demonstration project. Technology-transfer specialists, 

a no-till farming network to facilitate information 

exchanges, and research feedback inechanisms are the 

main benefits of the project. Many demonstration 

efforts concentrate on farmers in central South Dakota 

that could convert grasslands to croplands at the 

expiration of their CRP contracts. Most of the CRP 

lands are on highly erodible soils within watersheds that 

drain into the Missouri River where sediment loads and 

the sedimentation process are acute problems. No-till 

agriculture is the primary conservation practice being 

promoted in the area. 

Web Site on Arid and Semiarid Soils 

Proper soil management req~lires understanding the 

complex nature and properties of soil resources in 

relation to the environments in which they are developed. The fragility of ecological systems in arid and 

semiarid environments makes proper soil management 

imperative. Too often, improper management practices so degrade these soils that they cannot be reclaimed even after decades of careful use (Ffolliott et al. 

1995, Squires and Sidahmed 1998, Joyce et al. 1999). 

Relevant, accurate, and timely information on the 

nature and properties of soils formed in arid and 

semiarid regions must be available to soil scientists, land 

developers, resource managers, and decision makers 

when planning for hture conservation and sustainable 

use of soils and other natural resources in these regions. 

TALC supported a den~onstration project in the United 

States and Israel specifically to achieve the goal through 

Website technology. 

Demonstration 

A We bsite (http://www.ag .arizona.edu/OALS/ 

IALC/soils/home.html) has been developed by an 

interdisciplinary and international team of experts to 

provide an informational base about the nature and 

property of arid and semiarid soils and to establish links 

to other relevant sites (Casler 1996,1997). A slide-tape 
Chapter 2 

educational program titled, Classification, Properties, 

and Management of Arid Soils, has been adapted and 

posted to the site, along with supplementary information. Soil-survey information, maps, and publications 

of organizations responsible for soil management in 

arid and semiarid environments are also posted to the 

Website. A "Guide to Resources," which includes a 

directory to print publications, multimedia sources, 

databases, and maps, was prepared and is included on 

the site. The Website provides special "Educational 

Sites for Kids and Teachers," with links to inany related 

national and international sites-it is important that 

children begin to appreciate the need to manage soils 

and other natural resources at an early age properly. 

Some information in the module has been translated 

into Hebrew and future translation into Arabic is a 

possibility. 

The Website provides instantaneous, germane, and 

requested information about arid and semiarid soils to 

people any time from anywhere in the world. Efficient 

and timely accessibility of information is important to 

planners, managers, and decision makers as they attempt to mitigate the effects of and meet the natural 

resource needs of increasing numbers ofpeople who are 

moving into arid environments. 

Special l nitiative 

International Symposium on 

Sustainable Water Management and 

Wastewater Recycling 

Topics important to sustainable water supplies in 

arid and semiarid regions include implementation of 

technologies for irrigation with fresh and saline water, 

irrigation technology, rain-fed agriculture, use of sewage 

effluents in irrigation, groundwater protection and 

management, and the legal aspects of water 

management. The purpose of the international 

syn~posium held in Israel in May 1995 was to provide 

a forum for deliberating these topics, identifying relevant 

issues, and developing recommendations and strategies 

in relation to 3 areas. The areas were policies and 

strategies for the integrated management of land and 

water resources, research and development for improving 

water use efficiency, and national-level capacity building 

for integrated land and water resource management. 

Symposium participants were from 30 countries and 

included program directors and administrators ofwater 

and wastewater facilities, irrigation districts, and other 

government activities related to sustainable water 

management. At the beginning of the symposium, 

participants listed and prioritized the most important 

water issues in their countries. The list was compiled 

and distributed to attendees to provide a perspective for 

presentation of the background papers and discussion 

of issues. Working groups were formed to develop 

recommendations and present strategies on policies 

and action plans for the integrated management ofland 

and water resources. A steering committee was created 

to suggest continuing actions to maintain the 

momentum initiated by the symposium. 
Research and Development Projects 

Water Use by Dryland Oaks 

Part of the needed knowledge on the ecological 

functioning, hydrology, and management of oak woodlands in arid and semiarid regions is water transpiration 

by individual and stands of oak trees. Transpiration by 

oak trees affects the water budget of the oak woodlands 

and the responses of other components of these ecosystems. Tree harvesting and subsequent tree regeneration change the proportions of water contributed to 

other parts of the hydrologic cycle. Additionally, questions about how oak trees adjust their water demands 

to establish, survive, and grow on relatively dry sites in 

the region exist. In the Southwestern United States and 

northern Israel, an IALC-supported study has helped 

to increase our understanding about the adaptability of 

dryland oak species to ecosystem processes centering 

on transpiration by these trees. 

Study 

The heat-pulse technique estimated transpiration 

(Swanson 1994) in 2 adjacent stands of Emory oak 

(Quercus eemryi), a drought-deciduous tree in southeastern Arizona, and stands supporting Tabor oak (Q. 

ithabwensis), a deciduous oak, and Kerines oak (Q. 

calliprinos), an evergreen oak in northern Israel. Firewood had been selectively cut in 1 stand sampled in 

southeastern Arizona in 1980. Because firewood harvesting had last occurred 100 years ago on the other 

stand in Arizona, it represented unharvested conditions. Transpiration of 5 mature trees (60 years and 

older) was estimated in the first stand, while the transpiration of 5 mature trees and 5 postharvesting stump 

sprouts were measured in the second stand. Sapflow 

measurements obtained biweekly for 18 months on all 

Chaper 3 

Land Use and Reclamation 

of the sample trees were converted into estimates of 

transpiration. Eight oak trees were measured for 72- to 

240-hour periods at each of the 2 stands in northern 

Israel. These sapflow measurements were also converted into estimates of transpiration on a daily and 

annual basis. 

Only small differences in daily transpiration were 

discovered among the mature Emory oak trees on 

either of the stands sampled in southeastern Arizona 

(Ffolliott and Gottfried 1999,2000). However, differences in transpiration existed between the mature trees 

and the postharvesting stump sprouts. Average daily 

transpiration for the 18-month study by a mature tree 

in stands was nearly 17.5 L, while 4 L ofwater were used 

daily by individual postharvesting stump sprouts. On a 

per-hectare basis, the mature Emory oak trees in the 

unharvested stand transpired about 1,900 L of water 

annually. In comparison, the mature trees and 

postharvesting stump sprouts (collectively) transpired 

3,150 L of water annually in the harvested stand 

(Ffolliott and Gottfiied 1999, 2000). Average daily 

transpiration for Tabor oak trees in northern Israel was 

47 L, while that for IZermes oak trees was 28 L 

(Gottfried et al. 1999). 

Mature Emory oak trees in the unharvested stand in 

southeastern Arizona transpired 190 mm of waterabout 45% of the annual precipitation-while mature 

trees and postharvesting stump sprouts stocking the 

harvested stand transpired 3 15 mm of water (Ffolliott 

2000). The total amount of transpiration by the large 

number ofpostharvesting stump sprouts occupying the 

harvested site is the presumed reason for the finding 

(Ffolliott and Gottfried 2000). About 40% of the 

annual precipitation falling in the stand containing the 

deciduous Tabor oak trees in northern Israel was transpired, and nearly 70% in the stand supporting the 

evergreen IZermes oak trees (Gottfi-ied et al. 1999). The 
Selected hawesting of fuelwood has been a traditional land-use activity in the 

oak woodlands of southeastern Arizona. 

difference between these 2 species is attributed to the 

length of their respective growing seasons. 

In the oak woodlands of southeastern Arizona, firewood cutting removes approximately 10% to 1 5% of the 

mature oak trees. Even this low level of harvesting 

results in vigorous stump sprouting (Touchan and 

Ffolliott 1999). Therefore, harvesting Emory oak trees 

will probably affect the water budget of the harvested 

stand. Less water will be available to recharge groundwater aquifers, produce streamflow, or, depending on 

soil-moisture conditions, help other plants grow. That 

there is less precipitation available to recharge groundwater aquifers or produce streamflow after tree harvesting is contrary to the common observations of water 

yields increasing following the thinning or clearing of 

forest communities (Megahan and Hornbeck 2000). 

Continuing research is focusing on the effects of thinning dryland oak trees on transpiration rates. The 

results of the research should provide a basis for understanding how oak woodlands in arid and semiarid 

regions can be sustained under severe environmental 

conditions. 
Land Use and Reclamation 

Status of Sensitive Bird Species in 

Desert Grasslands 

The Southwestern Borderlands of the United States 

cover a unique and unfragmented landscape of 

mountains and valleys that contain exceptional 

biodiversity. The area is home to diverse plant and 

animal species that are rarely found in the United 

States. It was within this setting that a group of local 

ranchers met in 1990 to express their concern about the 

increasing encroachment of trees and shrubs onto 

otherwise productive grasslands and brainstorm a 

solution to the problem. Thus, the Southwestern 

Borderlands Ecosystem Management Research Project, 

headed by USDA Forest Service Rocky Mountain 

Research Station, was established to provide a scientific 

basis for developing and implementing comprehensive 

ecosystem management in the area (Edminster and 

Gottfried 1999, Gottfried et al. 2000). The evolving 

management effort includes strategies for sustaining 

natural processes, improving the productivity of 

woodlands and grasslands, providing wildlife habitats, 

maintaining an open landscape, and sustaining a viable 

rural economy and social structure. As a contribution to 

the Southwestern Borderlands Project, IALC supported 

a st~tdy to evaluate the status and management 

opportunities for sensitive birds species in the area. 

Many studies have focused on grassland bird conservation, but the area of focus has been the plains 

grassland of the Midwestern United States. Less attention has been centered on bird species of desert grasslands of the Southwestern United States. The study was 

designed to determine how sensitive bird species and 

assemblages of birds distribute themselves across a 

vegetation gradient in the desert grasslands of 

southeastern Arizona and southwestern New Mexico. 

Systematic observations and monitoring efforts in 

the range of conditions encountered in the Borderlands 

area formed the field basis for the study (Downard 

1998). It was found that the presence of woody plants 

affected the occurrence and distribution of individual 

and assemblages of bird species. Sites with less than 10% 

woody plant cover had proportionally larger populations of upland bird species. Sites with less than 20% 

woody plant cover supported semidesert grassland bird 

communities (Morrison 1999). Greater seasonal shifts 

in bird species richness were observed on sites with 

greater woody cover. Relationships between birds and 

specific plant species were also noted. Total bird abundance varied little between seasons except at sites with 

little woody cover. 

A prescribed burning program and lower livestockgrazing intensities will create a mosaic of diverse plant 

communities that would support the greatest birdspecies diversity in the Borderlands area. Prescribed 

burning and changes in livestoclz-grazing intensities 

will also promote a diversity of native rodent species, 

which will affect vegetative composition and serve as an 

important food source for many wild predators. Optimizing bird diversity and small mammal populations, 

while simultaneously achieving the desired goals of 

cattle production, will require prediction models that 

incorporate biological information, such as that obtained in the study. The models will also define costs for 

and tradeoffs between the benefits derived from various 

management activities. 

Decision-Support Systems for Improved 

Arid and Semiarid Land Management 

Many decision-making techniques are available to 

planners, managers, and other decision makers. Linear 

programming with a single objective is the basis of a 

relatively simple decision-making model. Assumptions 

of linearity for the objective hnction and associated 

constraints are inappropriate for complex problems of 

management, however. Problems most commonly 

confronted by managers of arid and semiarid lands 

involve most objectives. For exan~ple, minimizing the 

costs of a water management practice, while 

simultaneously maximizing the benefits from forage 

production, wildlife habitats, and soil and water 

conservation. It is also liliely that the set of such 

objective functions will be subjected to most linear and 

nonlinear constraints. Complex but realistic problems 

can be analyzed with decision-making models based on 

multiple criteria decision-making (MCDM) methods 
Chapter 3 

(Anderson et al. 1994, Yalzowitz and Hipel 1997, and 

El-SwaifE. and Yalzowitz 1998). IALC supports studies 

to formulate and test integrated and effective decisionsupport systems for strategic land-use planning and 

tactical management practices on arid and semiarid 

lands. 

Studies 

IALC studies consisted of efforts focusing on development of computer-based tools to apply in desert, 

rangeland, and wetland and riparian (streamside) ecosystems in the Southwestern United States and Middle 

East. Deciding the proper management activities in 

these ecosystems is critical because their structural 

integrity and ecological functioning can be easily lost if 

improper or inappropriate practices are initiated. 

A decision-support system to assess land suitability 

for management practices was formulated as an MCDM 

problem and linked to a geographic information system 

(GIs) for detailed spatial analysis in one study (Mendoza 

1997,2000). Alternative MCDM methods to combine 

factors affecting land suitability for management into a 

model to evaluate habitat suitability for wildlife species 

in a spatial format were developed. Desert tortoise 

( Gopherusflavonzarginatus) was selected as the basis of 

the model and decision-support system because of its 

endangered status in the Southwestern United States. 

The decision-support system represents a model that 

can be easily transformed into a user-friendly tool to 

evaluate land suitability about other natural resource 

management considerations. 

Understanding the spatial relationships between 

livestock-grazing patterns on rangelands and landscape 

characteristics is necessary to evaluate the impacts of 

livestoclz grazing on natural resource values and to 

select the most appropriate management program. 

However, determining optimal sustainable livestoclz 

stoclung rates is difficult because factors that influence 

forage production, effects of livestock grazing on 

erosional processes, and impacts of management on the 

functioning of rangeland ecosystems can change 

dramatically over a landscape. To help resolve the 

problem, LALC supported a study to develop a GIs that 

integrates spatially distributed landscape factors 

controlling livestock-grazing intensities into estimates 

of optimal sustainable stocking rates for rangeland 

management scenarios (Guertin et al. 1998, Mendoza 

and Guertin 1999, Cate 2000, Guertin and Mendoza 

forthcoming). The system, called RANGEMAP, is a 

tool that addresses resource production and conservation 

that enables managers to modify existing livestoclzgrazing management practices to sustain the 

environmental quality of rangelands. 

A decision-malung system for managers of wetland 

and riparian ecosystems has also been developed. The 

system links a groundwater model with other hydrologic and ecosystem- based models. Linking the models 

addresses the impacts of the proposed intewentions on 

the ecosystem's plant-water relationships and determines the interactions between surface water and 

groundwater resources on plant species seeded to rehabilitate the ecosystems (Ostfeld et al. 1998, Lansey et al. 

1999, Ostfeld et al. 1999). GISs provide visualizations 

of the static results obtained by the system. The system 

has been applied to a riparian ecosystem in the Southwestern United States that is being rehabilitated by 

identifying suitable plants to evaluate alternative planting schemes and groundwater levels. The system has 

also been applied to Lake Hula in northern Israel to 

determine the appropriate schedule and magnitude of 

releases through canal systems to maintain groundwater levels necessary to sustain vegetation in a restored 

wetland. In both cases, the system was a valuable and 

effective approach to operational decision making. 

Decision-support systems help people malie better 

choices for ecosystem consenration, sustainable use, 

and management. While the decision-support systems 

supported by IALC centered on habitat suitability, 

livestock stoclng rates, and plant-water relationships, 

they can also be applied to a wide selection of other 

management topics. Arid and semiarid land management decisions can be thoroughly examined before 

implementation to facilitate administration that meets 

societal demands for natural and economic resources 

on a sustainable basis. Operational decisions to accommodate short-term needs can also be analyzed from a 

long-term and systems-wide perspective. 
Land Use and Reclamation 

Public grazing lands in the Southwestern United States provide forage for livestock production and 

a variety of other multiple-use values. 

Demonstration Projects 

Improved Management of Public-Grazing Lands 

Managing public-grazing lands in arid and semiarid 

regions requires continuing forage production and use 

data, preparing resource status reports, and keeping upto-date on information about the applicable environmental laws and regulations. Satisfying these and other 

informational requirements affects rangeland managers 

and the ranchers receiving the grazing permits (Holechek 

et al. 1989). Additionally, managers must consider 

changing grazing allotment boundaries, rangeland 

management practices and improvement policies, and 

the permittees. Managers have routinely collected information about the changes, resulting consolidations, 

and relevant management factors. However, the information is often poorly organized and lacks an effective 

and user-friendly storage and retrieval system. The 

situation frequently leads to lost records, duplication of 

efforts, and wasted time and financial resources. 

An IALC demonstration project is helping to improve 

management of public-grazing lands in the 

Southwestern United States. The project is assembling 
historical and current information on the management 

of a representative amount of livestock-grazing 

allotments in central Arizona (Hutchinson and Blalze 

1999). The Forest Service has collected the data and 

information for more than 50 years and, recently, the 

University of Arizona has joined the effort. An 

interdisciplinary team of managers from the Forest 

Service and extension worlzers and information 

management specialists from the University of Arizona 

are facilitating access to the data and information 

through the World Wide Web and CD-ROM 

technologies. The team is also creating a model database, 

a user interface, and a database template to bring the 

information to planners, managers, decision makers, 

and local ranchers in a user-friendly package to promote 

learning, analysis, interpretation, and planning. Through 

these efforts, the team is facilitating enhanced public 

knowledge and understanding of public-grazing land 

issues in relation to environmental regulations. 

The availability of the Website and the CD-ROM 

products is announced at meetings, conferences, and 

worlzshops, where they are also demonstrated. 

Depending on the audience, demonstrations focus on 

the different attributes of the electronic products. At 

worlzshops involving management personnel, the 

demonstrations provide an overview of the entire datamanagement system but center on how to use the 

template to organize data sets. Demonstrations for 

students, teachers, and other educators address the 

analysis of data and other information to solve rangeland 

management problems. The usefulness of the Website 

and CD-ROM products is also presented at locally-led 

advisory committee meetings and Cooperative 

Extension conferences and worlzshops. 

Organizing the information in electronic formats 

fbrnishes a case study on the planning process used by 

the Forest Service and other federal agencies to develop 

livestock-allotment grazing plans that meet society's 

needs. The database template provides a model for 

people to build their own data-management systems 

that meet specific needs. As a result, the template 

maximizes the benefits of past financial inputs, offers 

new planning opportunities, and facilitates compliance 

with federal laws and regulations pertaining publicgrazing lands in the Southwestern United States 

(Hutchinson and Blalze 1999). The variety of delivery 

mechanisms available ensures that the broadest 

constituency possible is included in the clients served. 

Managers planning and implementing land-use practices 

on public grazing lands, researchers testing and 

validating predictive models of forage growth and 

livestoclz use of forage biomass, students and teachers 

learning about the ecological processes of livestoclz 

production, and decision malzers selecting the best 

course of action from a set of alternatives benefit from 

the project. The products and benefits of the 

demonstration project reach beyond Arizona and the 

Southwestern United States because livestoclz 

production is a traditional land-use of many societies in 

arid and semiarid environments. 

Dissemination of 

Watershed Management Information 

Watershed managers throughout the world are formulating and implementing actions that manipulate 

natural and human resources for specific objectives. 

Watershed management on arid and semiarid lands is 

often difficult, however, because water supplies and 

inherent resource productivity levels are limited. In 

addressing the difficulty, watershed management research in the Southwestern United States has led to a 

better understanding of the hydrology, ecology, and 

land-use potentials of the region's watershed lands 

(Balzer 1999, Balzer and Ffolliott 1999). The research 

has helped to establish management guidelines to 

satisfy the needs of a growing population in the region. 

However, the research efforts and their benefits to 

improved land stewardship are not widely known nor 

readily accessible. An IALC demonstration project has 

been undertaken to increase the accessibility of the 

information and to help planners, managers, and decision makers improve management decisions and effectively involve the public in the decision-malung process. 

Demons fra f/bn 

The University of Arizona and the Forest Service 

undertook a collaborative technology transfer effort to 

deliver research results and other information generated 

by the Beaver Creek Project in north-central Arizona 
Land Use and Reclamation 

(Balier 1999) to a diverse public (Balier and Young 

2000). A key part of the project consisted of bringing 

the information to the public through the World Wide 

Web. A Website (http://www.ag.arizona.edu/OALS/ 

watershed) was developed to feature Beaver Creekrelated references as examples of successful and 

unsuccessful projects in regional watershed management 

(Balier and Ffolliott 1999). The home page titled, 

"Watershed Management in the Southwest," includes 

topics on watershed management practices, order forms 

for references on watershed management practices in 

the Southwestern United States, and an interactive 

learning package on watershed management practices. 

Other technology transfer mechanisms are also available. A telephone system gives callers recorded twominute messages on sustainable management practices 

for watershed lands in arid and semiarid environments. 

Field trips to Beaver Creek sites introduce students, 

teachers, and the public to forest, wildlife habitat, and 

rangeland management practices and to the importance of watershed condition and function. The threepronged technology transfer effort optimizes 

information transfer on issues concerning watershed 

management on arid and semiarid lands to interested 

stakeholders. 

Clientele who have benefited from the increased 

availability of watershed management information include practitioners in the region, throughout the United 

States, and other countries; students, teachers, and 

other educators in high schools, colleges, and universities; and others interested in sustainable resource development and conservation. By bringing field-tested data 

and other information to people in formats that can be 

used for learning and decision making, the demonstration project is providing a valuable service to planners, 

practitioners, and educators concerned about hture 

land stewardship. Technology transfer methods that 

have been developed are being expanded to make other 

hydrologic, ecological, and economic data sets collected on other watersheds in the Southwestern United 

States available to researchers, managers, educators, and 

decision maliers (Baker et al. forthcoming). Included in 

these continuing efforts is research from watersheds in 

mixed conifer forests and chaparral shrublands. 

Special Initiatives 

International Workshop on 

Arid Lands Management 

The purpose of the workshop, held in Israel in June 

1994, was to establish the state-of-knowledge on the 

hnctioning of arid and semiarid land ecosystems, and 

their proper and sustainable management. IUC and 

other institutions at the workshop that support research and development on these ecosystems used the 

information to review the state-of-knowledge and to 

decide where best to allocate resources. Information 

was also distributed to managers to use in their management planning and programs. The workshop featured 

more than 250 participants specializing in ecological 

and climatological relationships, management planning and implementation, and mitigating or combating desertification. Invited papers on selected topics 

were presented; participants held discussions on population, community, and ecosystem management; and 

field trips were conducted to demonstrate how technological breakthroughs in desert management and combating desertification in Israel might be globally 

applicable. 

Invited and volunteer papers from the workshop 

discussions and a capstone synthesis paper on research 

and management implications formed the basis for a 

booli titled, Arid Lauds Mauaoemeut: Tom~ds Ecological Smtaiuability, which has become a reference for 

planners, managers, and decision maliers (Hoelistra 

and Shachali 1999a). Topics of chapters in the booli 

include an ecological framework for conservation and 

sustainability; ecosystems of deserts and their management; land use and management of arid and semiarid 

lands in the Southwestern United States, northern 

Mexico, the Negev, and Australia; and planning, simulation, and operation research approaches to management. A concluding chapter presents a synthesis of 

research and management opportunities and implications about sustaining the functioning of fragile ecological systems in arid and semiarid lands. The book is 

a source of information for policy maliers, representatives of legislative bodies, and interested segments of 

societies of countries in arid and semiarid regions where 

desertification is an issue. 
Chapter 3 

lnternational Symposium and Workshop on 

Desertification in Developing Countries: 

Why Can't We Control It? 

Desertification is occurring in many arid, semiarid, 

and dry subhumid regions of the world. The World 

Atlas of Desertification shows that soil degradation 

leading to desertification is a problem in developed and 

developing countries (United Nations Environment 

Programme 1992). The symposium and worlzshop, 

held in October 1994 in Tucson, Arizona, addressed 

the issue of desertification in developed countries and 

what can be done to control it. Participation was limited 

to about 150 scientists and land managers from 15 

countries concerned about the increasing threat of 

desertification. Participants focused on monitoring and 

assessment techniques and mitigative interventions. 

While many lessons had already been learned about 

desertification, organizers felt that the participants 

should concentrate their efforts on the successes from 

a few countries and distill the information into a 

transferable format for extrapolation. 

Key papers presented at the symposium and worlzshop 

were published in a book titled, Desertification in 

Developed Countries to facilitate dissemination to a 

wide audience (Mouat and Hutchinson 1995). Book 

chapters address social, economic, political, and 

institutional factors that have resulted in successful 

interventions; monitoring and assessment of the 

magnitude and severity of desertification in developed 

countries and worldwide; and techques tried to halt or 

reverse the desertification processes. Recommendatioix 

on how to combat the effects of desertification and 

other forms of soil degradation common in arid and 

semiarid environments are also presented. 

lnternational Symposium and Workshop on 

Connecting Science with Community Action in 

Combating Desertification 

A symposium and workshop on desertification was 

held in May 1997 in Tucson, Arizona, to explore 

methods of linking science to community action. The 

initiative was a follow-up to the above 1994 symposium 

and worlzshop on desertification, however, this initiative 

included a wider audience of scientists, managers, and 

community action specialists. An outcome of the 1994 

activity was the realization that there was a gap between 

the scientists researching the processes, causes, and 

effects of desertification and the people daily facing its 

effects. Therefore, the 1997 initiative focused on 

exploring and evaluating the methods for liillung the 

science to community action. Another focus was to 

review interventions and other programs to combat 

desertification at the local level by examining the 

successes and failures and extracting lessons. 

Twenty of the papers presented at the symposium 

and worlzshop, including research-oriented papers, regional case studies, and community action studies, were 

published in a special issue of the Journal of Arid 

Environments (Mouat and McGinty 1998). The papers embody the concept that desertification and soil 

degradation are inseparable from sustainability. People 

lznow something about the processes, causes, and status 

of desertification in the world, but to successfully 

combat it, human interventions must be applied before 

the processes and causes lead to irreversible situations. 

Participants at the symposium and worlzshop concluded that carefully planned community action supported by science can help reverse the processes and 

attain a level of sustainability. 

lnternational Training Workshop on 

Ecological Systems 

The training worlzshop, held in November and 

December 1995 in Israel, was presented to managers, 

policy malzers, scientists, and academics from 20 

countries containing arid or semiarid regions who were 

interested in sustaining ecological systems. Topics 

presented included soil-water-plant-nutrient 

relationships; animals in desert and desert-like 

conditions; and appropriate agriculture, agroforestry 

practices, afforestation, and livestock-grazing practices. 

There was a special emphasis on participation of men 

and women in management and implementation of 

programs focusing on these topics at economic levels 

ranging from subsistence to a market-oriented economy 

and sustainable economic and regional growth. The 

format consisted of formal lectures, open discussions, 

and visits to agricultural production and industrial 

manufacturing enterprises, water harvesting projects, 
Land Use and Reclamation 

afforestation interventions, and restoration sites. 

Trainees prepared reports that linked n~anagement and 

development practices considered in the training 

workshop to proposals that addressed these practices in 

ecological systems in their respective countries. The 

reports were presented to trainees and staff in a plenary 

session at the conclusion of the workshop. An evaluation 

made by the trainees at the end ofthe training workshop 

ranked the topics and other activities of the initiative in 

relation to their importance to the trainees. 

Technical Training Course on Mitigating Risks 

to Conservation and Sustainable Use of Water 

and Other Natural Resources 

The course, held May and June 1999 in Jordan and 

Israel, for trainees from Jordan, the Palestinian 

Environmental Authority, and Israel, concentrated 

natural climatic variability when planning for 

management of water and other natural resources. The 

format consisted of formal lectures and informal 

Participants in a technical training course on natural resource management in the Middle East viewing 

ecological conditions affected by drought and desertification processes and discussing 

what might be done to mitigate these degraded conditions. 
Chapter 3 

discussions, laboratory sessions, and field trips. Trainees 

learned about the basic concepts and principles of 

natural resource management practices, the techniques 

and applications of dendrochronology (tree-ring dating) 

to generate information on climatic regimes, applications 

of stochastic generators of the climatic regimes when 

planning for conservation and sustainable development 

ofwater and other natural resources, and the importance 

of local participation when planning natural resource 

management. A key outcome from the course was the 

identification ofissues for cooperation among countries 

affected by drought and desertification and a 

prioritization ofthe issues for possible follow-up actions. 

Course modules were chapters of the training manual 

prepared for the initiative (Touchan et al. 1999). The 

training manual has been widely distributed to interested 

organizations and people in the Middle East since 

course completion. An evaluation made by the trainees 

at the end of the initiative indicated that the technical 

training course was a success, had met anticipated 

expectations, and could be a model for future 

collaborative efforts. 

Land Management Workshop 

IALC hosted a special initiative titled, "IALC Land 

Management Worlzshop: A 10th Anniversary 

Celebration of USFS, CSREES, Israel, and IALC 

Partnerships," in November 1999 in Reno, Nevada, to 

update government land managers and others on the 

activities and accomplishments of IALC's scientific and 

technical programs. The focus of the workshop was on 

water andwatershed management; seedbanlzs and crusts; 

wildlife, grazing, and ecology; and decision-support 

systems. A panel of scientists considered each focus area 

by presenting IALC-sponsored research and 

development projects and supporting demonstration 

projects (International Arid Lands Consortium 1999). 

A group discussion followed the presentations. Most of 

the 70 participants that attended the workshop were 

researchers and administrators from the respective IALCmember institutions. Others included representatives 

from the Forest Service and Cooperative State Research, 

Education, and Extension Service. The initiative 

successfully brought together researchers and managers 

from the United States and Israel to share their expertise 

and experiences in building a global community of 

planners, managers, and decision malzers dedicated to 

improved stewardship of arid and semiarid lands. 
Processes Enhancing the 

Management of Ecological Systems 

Research and Development Projects 

Impacts of Water Capture on Plant Virus Vectors 

Water that is captured and remains in natural depressions can influence the character and dispersal patterns 

of the vectors of plant viruses. In turn, the water can 

spread into agricultural croplands near the catchments 

and impact crop production (Irwin and Ruesinlt 1985, 

Irwin 199 1 ) . The significance of these events on sites in 

Israel with high-input agriculture is the focus of the 

IALC study. The study is designed to clarify the effects 

of natural water catchments on populations and the 

dispersal patterns of leafhoppers, aphids, whiteflies, and 

thrips, which are potential vectors ofplant viruses in the 

region. 

Three sites at about the same elevation within 1 Itm 

of each other with different water-capture potentials 

were selected for study. Their differing ability to capture water has resulted in differences in plant characteristics. One site supports more grasses, annual flowers, 

and Acacia trees than the second site, while the third site 

was essentially bare. Liquid-filled yellow pans and malaise traps were used to sample insects in the spring of 

consecutive seasons. The pans attracted specimens flying in the plant boundary layer (> 10 m above ground), 

while the traps collected specimens within the surface 

boundary layer (<lo m above ground), thereby sampling movements of the vectors throughout the site 

habitats. 

Results to date suggest that aphids and whiteflies are 

abundant on sites that captured less water and 

leafhoppers and thrips are abundant on the site with 

more water. These differences were greatest following 

a winter with heavy rains and minimal following a 

winter with almost no rainfall. No temporal (seasonal) 

off-setting of flight activities was detected among the 3 

sites. The results suggest that nearby water-capture 

regimes do not off-set the life cycles ofthe vectors. Most 

flight activity of the insects occurred in the springflight patterns of aphids and trips peaked earlier than 

those of leafhoppers and whiteflies. The 3 sites differed 

in the numbers and types of insect vectors observed in 

relation to the amount of water they receive. 

The study is improving the understanding of the 

effects of captured water on the life cycles of potential 

vectors of plant viruses. While further analysis of the 

data will be made, findings to date have implications for 

management of agricultural crops adjacent to sites of 

natural water catchments. If the availability of water 

affects the types, abundance, and flight patterns of 

insect plant vectors, a holistic form of management 

might be necessary to minimize the occurrence of plant 

viruses that reduce the productivity of threatened 

agricultural crops. 

Climate Change, Allometry, and Tree Hydraulics 

The rise in atmospheric CO, anticipated by the end 

of the 2 1st century is expected to increase air temperature and atmospheric vapor-pressure deficits. Managers 

of forests, woodlands, and plantations are concerned 

about the effects these increases might have on trees. 

The most relevant allometric component controlliilg 
Chapter 4 

water transport for trees is the ratio of biomass allocated 

to photosynthetic tissue (leaves) relative to waterconducting tissue in the stein (sapwood) (Running 

1980a, 1980b, Holbrook and Sinclair 1992). Within 

the genus Pinus, trees decrease the ratio of bionlass 

allocated to leaves relative to sapwood in response to 

rising air temperature and atmospheric vapor-pressure 

deficits. Therefore, these climatic changes could alter 

the water relation of trees and forests of this genus. In 

Nevada, stands of ponderosa pine ( Pinus ponderoscc) in 

a desert-to-montane transition gradient were used in 

the IALC study to determine the effects of climaterelated shifts in biomass allocation on the water relation 

of mature trees. 

Study 

Researchers used published values to test a theoretical prediction that ponderosa pine trees decrease their 

investments in leaves relative to sapwood as air temperature and atmospheric vapor-pressure deficits increase 

(DeLucia 1999). From these predictions, researchers 

found that desert ponderosa pine trees would have 

higher rates of water transport per unit sapwood area 

than montane ponderosa pine trees because of larger 

diameter tracheids in the sapwood (Maherali and 

DeLucia 2000b). The low ratio of biomass allocated to 

leaves relative to sapwood and the higher sapwood 

conducting efficiency should lead to an increase in 

hydraulic conductivity and higher transpiration rates in 

desert trees. 

Desert and montane trees should have similar 

vulnerability to xylem embolism and soil-to-leaf water 

potential gradients during the growing season (Maherah 

and DeLucia 2000a). Despite relatively higher 

allocations to sapwood, desert and montane ponderosa 

pine trees would not differ in their reliance on stored 

water reserves. A loss in foliage storage capacity offsets 

gains in sapwood water-storage capacity through high 

allocation to sapwood in desert trees. The advantage of 

the high allocation to sapwood in warm, dry environment 

is increasing the hydraulic conductivity to prevent 

xylem embolism induction. A growth chamber study 

revealed that there were no interactions between elevated 

temperature and CO, on water transport in ponderosa 

pine seedlings. Similar to their mature counterparts in 

the field, seedlings reduce the ratio of biomass allocated 

to leaves relative to sapwood and have higher hydraulic 

conductivity in response to elevated air temperatures 

and atmospheric vapor-pressure deficits. 

Results fi-om the study suggest that rising air temperatures and atmospheric vapor-pressure deficits could 

exert more influence on tree-water relations than elevated CO, in a future climate (DeLucia et al. 2000, 

Maherali and DeLucia 2000a, 2000b). A common 

garden study showed that although populations of 

desert and montane ponderosa pine trees differed genetically, none of the variability was associated with 

ecotypic divergence. Therefore, differences in water 

relations of desert and montane trees might be related 

to phenotypic plasticity. Consequently, phenotypic 

plasticity of a species, with respect to its adaptation to 

changes in temperatures and water relations could 

determine the composition of future forests under the 

warmer conditions resulting from elevated atmospheric 

CO,. 

A doubling of atmospheric CO, concentrationconsidered stable for the last 100,000 years-is predicted to increase global air temperatures about 4" C in 

the next 100 years (DeLucia 1999). The CO, rise will 

be unprecedented and raises the question of how will 

long-lived trees respond to the climate change. What 

physiological and morphological cl~aracteristics will 

produce the most robust trees in the future is not 

known. However, inferences drawn from the study 

about combinations of traits that could be adaptive to 

climatic changes increases our understanding of the 

capacity of future forests to fix atmospheric carbon and 

survive. The knowledge should help managers select 

ecologically adapted genotypes for wood production 

and other purposes in warm and dry environments that 

are similar to that studied. 

Modifying Toxic Compounds in 

Leguminous Trees 

Fodder from leguminous trees is part ofthe roughage 

diets of livestock in many arid and semiarid countries. 

While the fodder is not necessarily a nutritional dietary 

component, it is used when nutritional forage is 

unavailable. However, anti-nutritional effects of 
Processes Enhancing the Management of Ecological Systems 

leguminous fodder can be alleviated through 

modification of ruinen microbial populations by 

isolating, culturing, and reintroducing microorganisms 

capable of transforming anti-nutritional compounds 

into susceptible ruminants (Gregg and Sharpe 1991, 

Gregg 1995). The IALC study used two approaches to 

obtain these modifications. Isolating and characterizing 

rumen organizations capable of modifying known antinutritional factors was one approach, while identifying 

anti-nutritional factors in legunlinous trees with potential 

value as fodder was the other. 

The hypothesis tested was that microorganisms from 

ruminants adapt to diets containing leguminous fodder 

modify or degrade anti-nutritional factors better than 

rumen populations from livestock fed conventional 

roughage diets. Researchers from the International 

Livestock Research Institute, Addis Ababa, Ethiopia, 

and the University of Illinois developed the hypothesis 

concerning the effects of feeding fodder from the 

Acacia angustissinza to sheep. A. angustissima is a 

tropical legume, which could be a fodder tree (Hocking 

1993), although the fodder is toxic to sheep. 

Completed laboratory experiments and experiments 

in progress are testing the validity of the hypothesis. 

Metabolic transformation by rumen inocula of 3 classes 

of anti-nutritional factors in leguminous foddermimosine, tyramine, and ferulic acid-indicated that 

there was no difference in the rate or extent of modification when sheep were fed leguminous-supplemented 

or conventional roughage diets. Organisms that mod@ 

anti-nutritional factors of leguminous fodder were 

present in rumen populations in Africa and the United 

States. Isolating cultures of these organisms is possible, 

which could be useful in developing rumen inocula. 

A bioassay was conducted on rats to identify and 

evaluate anti-nutritional factors present in diets of 

varying amounts of A. angustissima and comparative 

diets of A. aupxstissima and alfalfa. Other experiments 

will be conducted to determine whether anti-nutritional 

effects of A. augustimmisa are due to the presence of 

phenolics or whether a synergistic effect between the 

phenolics and unidentified compounds exists. DNA 

collected from fecal samples will be analyzed to assess 

the antimicrobial effects of the phenolics present. In 

vitro incubations of phenolic containing plant extracts, 

with previously isolated bacteria, will help identify 

organisms capable of detoxifying the anti-nutritional 

factors of A. an~usissima. 

While limited to 1 leguminous tree species and 1 class 

of livestock, results from the study should further our 

understanding about toxic compounds in leguminous 

trees, their potential effects on livestock, and what 

might be done to malie it palatable. Leguminous trees 

are multi-purpose because they provide wood resources 

for local uses, are a source of human food, and provide 

shade for livestocli. Many species also symbiotically fix 

atmospheric nitrogen needed in nutrient-deficient 

ecosystems. Knowing about the fodder resources of 

these trees allows for their efficient and varied use. 

Genetics and Propagation to Improve the 

Management and Culture of Plant Resources 

Many IALC research and development projects 

continue to focus on improving planting stock through 

genetics and other techniques to increase yields and 

qualities of plants valuable to people, develop plants 

that can do well in adverse environments, and produce 

plants for special uses, such as conservation planting or 

agroforestry practices. However, other world regions 

have received more research and development efforts to 

improve planting stock than the arid and semiarid 

regions. IALC is addressing the deficiency by supporting 

studies that will increase knowledge about how genetics 

and other improvement techniques can conserve plant 

resources in arid and semiarid environments. 

Cacti produce food crops efficiently under dry conditions. However, cacti as a food crop occurs mostly in 

areas where they are indigenous. The objective of a 

cactus breeding study supported by IALC in southern 

Texas was to combine cold hardiness, low seediness, 

high yields, and high sugar concentrations to produce 

high quality, adaptable, appealing cacti food crops 

(Chavez-Ramirez et al. 1997, Parish and Fellier 1997, 

Wang et al. 1997, Fellier et al. 1998, Wang et al. 1998, 
Wang et al. forthcoming). Seeds from crosses of native 

Texas spiny (Opuntia lindbeime~ii) and several commercial spineless fruit varieties that are found in Mexico 

and elsewhere were obtained for the study. The native 

variety is cold hardy in southern Texas, and it was 

expected that progeny from crosses with the native and 

non-cold hardy Mexican varieties would have the 

desired cold hardiness and fruit quality. 

Among the promising crosses was one between a 

spineless, large, red-fruited variety, with small seeds, 

high yields, a dwarf-compact shape, good disease resistance, and average sugar concentration. An outcome of 

the breeding effort was a clone of a spiny yellow-fruited 

variety, with excellent firmness and a high sugar content. Unfortunately, the clone is too tall to harvest 

efficiently and has disease problems. All of the crosses 

between the 2 Chilean clones were noteworthy because 

they had the greatest sugar concentration and lowest 

seed size. While these clones are low yielding, combinations of the clones with high-yielding varieties should 

result in genotypes with desirable food production 

characteristics. When compared to citrus, cacti is more 

cold hardy, requires less water, and its fruits are ripe 

when citrus is not. Techniques for emasculation, hybridization, and germination have been developed to 

promote cacti as a food. 

IALC also supported a study to improve propagation 

of Rocky Mountain juniper (Juniperus scopulorum) 

and eastern redcedar juniper (J. vi@nima). The purpose of the study was to help nurseries meet production 

levels by identifying factors critical to rooting stem 

cuttings. Identifying factors enables manipulation to 

help ensure successful rooting for conservation plantings 

in the Great Plains (Wagner et al. 1992). Factors known 

to affect rooting (adventitious root formation), which 

were investigated, included genotype, mother-plant 

growing conditions, cutting type and position, exogenous growth-regulator application, and dormancy 

level or collection timing. Stem cuttings from lmown 

sources planted in a Great Plains Agricultural Council 

provenance trial were studied to determined genetic 

variability within the species. To evaluate the effects of 

mother-plant growing conditions, cuttings were collected from sources in South Dakota, Nebraska, and 

New Mexico to provide climatically distinct growing 

environments. Cutting type and position experiments 

examined differences between juvenile and mature 

cuttings and the location on the crown where the 

c~lttings originated. Another experiment was accomplished to investigate the effects of exogenous hormone 

applications. Collection dates in March, April, June, or 

July, and October assessed dormancy level or collection 

timing. 

Overall, the stem cuttings studied did not root well. 

Variability in stem rooting was observed within and 

among species, collection site, and individual trees. 

Cuttings from some individual trees did root well for 

one or more collections (Wagner et al. 1994). Cuttings 

from younger trees (less than 3-years old) generally 

rooted well. These experiments indicate that there is 

some underlying genetic control on the ability of Rocky 

Mountain juniper and eastern redcedar stem cuttings 

to produce adventitious roots. However, there may be 

potential for large-scale vegetative propagation of these 

important trees to meet the nursery demands for juniper stock for use in conservation plantings. 

Scientific and practical benefits are expected from a 

study to increase knowledge about the population and 

individual genetics of Mediterranean pines. Pine forests 

in the Middle East, and other arid or semiarid environments, respond to global warming according to their 

ability to withstand increasing drought (DeLucia et al. 

2000). Additionally, identification of genes and genotypes of pine, with particular abilities to withstand 

drought, should be applicable in afforestation efforts 

where conditions are too dry for pine cultivation. 

Researchers in Israel and the United States are using 

two approaches to identify genes and proteins induced 

by drought stress in Allepo pine (Pinas balepensis), a 

species with renowned resistence to drought (Korol 

and Schiller 1996, Schiller and Cohen 1998). One 

approach is using young seedlings to examine proteins 

induced by water stresses. Seedlings are subjected to 

stress by withholding water or to a slowing induction by 

subjecting them to varying concentrations of glycerol. 

They observed that total protein content in roots of 

seedlings subjected to rapid stress was reduced to 20% 

within 18 hours. The protein content of hypocotyls 

decreased at a slower rate. Coomassie staining of total 

proteins separated by SDS-PAGE did not show differences between stressed and unstressed seedlings. However, SDS-PAGE of hypocotyl boiling-stable proteins 
Processes Enhancing the Management of Ecological Systems 

facilitated identification of bands induced by the stress 

treatments. When biotin was incorporated into the 

proteins produced during treatments, additional proteins induced by stress were detected. The various 

bands reached their maximums at different stress levels. 

An antibody to a peptide in LP3 has also been used to 

examine induction of dehydrins. The antibody was not 

specific and reacted with several proteins between 15 

and 90 kDa. Some bands decreased or increased during 

stress treatments. 

The second approach uses six-month-old seedlings 

and differential screening of a cDNA library to isolate 

the clones of induced genes. The library is made using 

roots of stressed seedlings and was screened using 

probes generated from stressed and unstressed roots. 

Of the 21,500 clones examined, 156 that represent 

genes induced by water stress were identified. Fifteen of 

the identified genes have been sequenced and northern 

blot analyses were used to examine the expression of 7 

of those genes. The genes induced by stress included 

those encoding a LEA-like protein (late-embryogenesisabundant), a lignin biosynthetic enzyme (4-coumarate 

CoA ligase), a cyclophilin, an endochitinase, a sucrose 

synthase-type protein and some that were not similar to 

previously identified genes. Next, the study will determine if any of the characterized genes encode the 

induced proteins that were identified in the first 

approach. 

Climate changes will likely create many challenges 

for ecologically-sound management of arid and semiarid lands. Climatic changes could encourage further 

aridification in the Middle East and Southwestern 

United States. Anticipated water stresses could affect 

specific plant communities by causing displacements 

and extinctions. Although a significant amount of 

theory exists, there is little evidence that core populations of plants will be more resistant, equally resistant, 

or less resistant to climate changes than peripheral ones. 

An ongoing IALC study is revealing whether there are 

genetic variabilities in sensitivity to environmental 

stresses between core and plant peripheral populations-particularly in those predicted to increase through 

desertification. Predictions of which plant populations 

will be biogenetic resources are possible as well as 

predictions on the roles of drought-responses of genes 

involved in adaptive functions. To test the hypothesis 

that the genetic complexity for drought-response genes 

is greater in peripheral than core plant populations, 

structures of gene families for drought-responsive and 

nonresponsive genes are being evaluated. The evaluation is occurring in 2 species, Dactylisglomerata and 

Trzfolimz purpwezlnz, with core populations in the 

Mediterranean region and peripheral populations in 

the desert-to-nondesert transitions in Israel. 

Standard molecular biological procedures in samples 

of each of the 2 species in 3 core populations and 3 

peripheral populations are measuring genetic variability in the 2 plant populations. The diversity of droughtinducible genes, drought-repressible genes, and genes, 

with transcript levels that do not change in response to 

drought, will be studied. Testing for survival will measure the drought-resistance physiological attributes of 

individual plants into drought by relating leaf-water 

potential to transpiration and water acquisition from 

the soil. Analyses will be done to determine if genetic 

variability for any of the drought-inducible genes is 

greater in peripheral than core populations. The study 

is significant because the results from the native plants 

could be directly translated for use in studies on crop 

plants. If complexity of the gene families for droughtinducible genes is greater in peripheral than in core 

populations, the hypotheses proposing positively adaptive functions for these genes will be supported. 

The importance of improving planting stock for 

conservation and improved food and forage production 

for humans, livestock, and wildlife on arid and semiarid 

lands is evident. As shown by the IALC studies through 

carefully conducted research and development, plant 

yield and quality can be improved. Additionally, the 

studies have shown that plants can be developed that 

can sustain themselves on harsh sites, under extreme 

environmental stress, and that plants can be adapted for 

special uses. These studies are benchmarks because of 

the increased knowledge obtained about improving 

planting stock for species and regions not previously 

investigated. One particularly important benefit of 

genetically improving planting stock, accomplished by 

these studies, is that once the desired change is obtained, 

it can be maintained for many generations through 

careful planting-stock management. Genetic material 
Chapter 4 

identified through screening or developed through levels of colonization are positively correlated with 

plant-breeding programs can be kept intact through organic matter and soil moisture. The rapid changes in 

improved methods of vegetative propagation. species richness and trophic structure indicate that 

Nematode communities also respond to soil moisture 

Nitrogen, Productivity and 

Soil Biota in Desert Ecosystems 

Arbuscular mycorrhizal colonization rates on the 

Jornada Experimental Range are consistently higher 

than those in the Negev and are positively correlated 

Deserts, which cover more than 5% of the earth,s with soil moisture-similar to that the Negev. Distribuland surface, are expected to increase significantly in tions of heterotrophic bacteria on the Jornada are high 

areal extent with increasing CO, levels and global near established plants and when soil moisture is high. 

warming. When lands that are sensitive to desertifica- As predicted, on both study sites the responses of 

tion processes are also considered. nearlv one-third of arbuscular mycorrhizal fungi and heterotrophic bacte- L J 

the earth's land surface is likely to be subject to the ria are not as dramatic following a second and third 

combined nitrogen, water, and other stresses addressed rainfall event. Researchers are waiting for additional 

in lALC study. The capabilities of these lallds to laboratory analyses to identify correlations between 

sustain human activities will be tied to the productivity biotic communities and nitrogen levels. 

of the plants growing on them. While plant productivity is related to available soil moisture, high year-toyear variations in soil moisture are difficult to correlate 

with annual rainfall inputs (Bottner 1985, Keift et al. 

1987, Hartley 1997). A major reason for these variations is the soil's nitrogen status, including the amount 

of extractable nitrogen available in the plants and the 

amount tied up in soil biota. Under the best of circumstances, the complex fluxes between soil-nitrogen pools 

are poorly understood. This is the case in arid ecosystems where the fluxes can change quickly following 

rainfall. 

Soil samples have been collected in the Negev Desert 

in Israel and on the Jornada Experimental Range in 

southern New Mexico to determine how total nitrogen, soluble nitrogen, and plant nitrogen pools in 

desert soils change with time and following rainfall 

events. How observed changes in nitrogen relate to 

plant productivity and follow populations of arbuscular 

mycorrhizal fiungi, heterotrophic bacteria, and soil 

nematodes are also being evaluated in the 2 ecosystems. 

The ecosystems vary in amount and pattern of rainfall 

inputs received, and both are under stress from livestock grazing. 

While analysis of the study data is incomplete, the 

following findings have been reported. Halophytes in 

the Negev are arbuscular mycorrhizal fungi and the 

/rnp/icaf/bns 

Results from the study will provide a better understanding of the interactions among nitrogen pools, 

plant productivity, and populations of soil biota in the 

desert ecosystems of Israel and the Southwestern United 

States. Once available, these results can be translated 

into inputs for planning management and use of plant 

communities to sustain livestock grazing and other 

human-induced activities on desert lands and lands 

sensitive to desertification. Increasing areas of the earth's 

land surface are falling into this category. 

Patchiness and Ecological 

Flow Effects on Ecosystem Functioning 

Seemingly bare surfaces of many soils throughout 

arid and semiarid regions of the world are actually 

mosaics of macrophytic patches of shrubs and herbaceous plants. These plants are growing in soil mounds 

and microphytic (biogenic) patches of algae, mosses, 

lichens, bacteria, and cyanobacteria that are growing on 

soil crusts. Due to the limited amount ofwater, soil, and 

nutrients available to organisms of these patchy ecosystems, patterns of spatial heterogeneity at the landscapelevel develop (Zaady and Shachak 1994, Shachak et al. 

1999). The distinguishing features of the heterogeneity are the spatial distributions of soil, rock, shrubs and 

other herbaceous plants within the matrix of soil crusts 
Processes Enhancing the Management of Ecological Systems 

formed by the microphytes. When an abiotic or biotic 

variable shows 2 discrete states at a single level of 

resolution, the spatial heterogeneity is called patchiness 

(Shachak et al. 1999). The patchiness of arid or semiarid landscapes controls population abundance, species richness, biomass accumulations, and flows of 

water and nutrients in the ecosystems. IALC supports 

studies to learn about the character of natural and 

human-made patchiness, ecological flows, productivity, and diversity of patchiness on arid and semiarid 

landscapes. 

Studies 

The studies are designed to understand the 

relationships among patchiness, microbiotic crusts, 

ecosystem resources, productivity, and diversity better. 

The studies also intend to show the implications of 

these relationships for management of arid and semiarid 

lands and the effects of patchiness on the cycling of 

nutrients and other resources. Additionally, the research 

hopes to indicate redistribution of these ecosystem 

resources in the deserts of Israel and Southwestern 

United States. Methodologies used by researchers in 

the studies have been presented elsewhere (Zaady et al. 

1996, Offer et al., 1997, Shachak and Lovett 1998, 

Monger and IGdron 1999, Dawson et al. forthcoming) 

and, therefore, are not elaborated here. However, some 

significant findings from these studies are presented. 

Trends in species diversity with respect to harvesting 

shrubs, scalping vegetation, and spraying herbicides 

and relationships among patchiness, water flow, and 

plant responses in the Negev have been revealed in 1 

study. Harvesting shrubs causes the size of the macrophytic patches to increase, while there is a decrease in 

the size of microphytic patches. The trend results from 

the dispersal pattern of seeds on the area. A large seed 

bank can accumulate in the macrophytic patches in 

spring and summer. Without competing shrubs, a high 

germination rate of herbaceous plants exists on the soil 

mounds of macrophytic patches and in the interface 

between macrophytic and microphytic patches. This 

promotes an increase in the macrophytic and decrease 

in microphytic patches. 

A predictive model, developed by the researchers, 

shows that the increase in macrophytic patches and a 

decrease in water-shedding microphytic patches results 

in increased runoff interception by the macrophytic 

patches (Shachak et al. 1999). Removal of aerial portions of the shrubs alters patch quality, increases patch 

size, and increases total surface area covered by macrophytic patches. This causes an increase in water retention and water availability for plant growth. The net 

effects of harvesting shrubs are increases in species 

richness and variation in composition of both patch 

types. 

After scraping to remove above-ground vegetation 

and expose the soil surface, Atractylis serratuloides was 

the first shrub to colonize the area. When these shrubs 

grow, soil accumulates and forms a mound under the 

shrub canopy. The soil mounds enable herbaceous 

plants and Nnaea mucronata shrubs to become establish. Development of the 2 shrubs, A. serratdoides and 

N. mucronata, allows for soil accumulation and an 

increase in the size of macrophytic patch. The scraping 

treatment creates large rnicrophytic patches and an 

increase in the ratio between the microphytic and 

inacrophpc patches. The hlgh proportion ofmicophytic 

patches preventing infiltration of surface water and 

explains the relatively high runoff generation and low 

water retention following the treatment. Patchiness 

modification by scraping, and its effect on water flow, 

helps to explain the decreases in species richness in both 

patch types, compositional variations, and patch type 

differences. Spraying with the herbicide Simazine eliminates all herbaceous plants and A. serratuloides. Areas 

sprayed usually become inhabited by only N. mucronata. 

Without herbaceous plants on the soil mounds, the 

mounds disintegrate and the soil erodes. These processes cause a decrease in the size of the macrophytic 

patches and an increase in the size of microphytic 

patches. 

The accumulation of soils is a limiting resource in 

desert ecosystems. However, loose soil mounds in 

macrophytic patches can permit relatively high production of annual plants. In another study, depositions of 

atmospheric particles on macrophytic and microphytic 

patches were measured in the Negev to determine to 

what extent atn~ospheric particle depositions are responsible for soil-mound formation (Offer et al. 1997). 

Fine particles consisting mostly of mineral dust are 

deposited at similar rates in macrophytic and microphytic 

patches. However, coarse particles from plant detritus 
Chapter 4 

The patchiness of the Negev Desert and other deserts of the world influences on-site water retention and, 

as a result, the water available for plant growth. 
Processes Enhancing the Management of Ecological Systems 

are deposited at greater rates in macrophytic than in 

microphytic patches (Zaady and Shachak 1994, Zaady 

et al. 1996). Coarse particles have higher concentrations of carbon and nitrogen than fine particles. Typical 

soil mounds take up to150 years to develop. Therefore, 

ecosystems that are slow to recover from disturbances, 

such as overgrazing by livestock, excessive firewood 

cutting, or herbicide applications, reduce the 

abundance of macrophytic patches. 

Depositions of dust, organic matter, and feces, and 

their redistribution by runoff in the Negev, have also 

been studied in relation to patchiness and rainfall. 

Higher accumulations of these dry depositions obsewed in the winter are probably due to climate and 

biological activity (Offer et al. 1997). Depositions of 

dust are higher in soil-crust patches than under shrubs 

of macrophytic patches. Contrary to popular theory, 

shrubs do not act as dust traps but instead as umbrellas 

that prevent dust deposition underneath shrub canopies. Soil erosion that is higher than dust deposition 

indicates that the ecosystem is in a state of soil accumulation, although the soil accumulations are nonuniform. Runoff redistributes dust deposits so that the rate 

of soil accumulation under the shrub is higher than that 

on the soil crust. The difference in soil accumulation is 

responsible for creating differences between the flat 

crusts and soil mounds under shrubs (Shachak and 

Lovett 1998). Patchiness from dry deposition, and its 

redistribution, is the main controller of productivity 

and diversity of the ecosystem. 

In the Chihuahuan Desert of the Southwestern 

United States, occurrences of fragile physical crusts on 

soil surfaces are more common than those of microbiotic crusts. A finding from an IALC study indicates that 

microbiotic crusts are confined to stable soils on sites 

protected from soil degradation, while physical crusts 

are on almost any bare soil (Monger and Kidron 1999). 

Microbiotic crusts are ofien found on the sheltered 

leeward sides of quartz dunes that mesquite has stabilized (Prosopisspp.) shrubs. Their scarcity in bare sandy 

areas suggests that they are vulnerable to soil erosion 

and are burial by sand. Microbiotic crusts generally 

cover gpysiferous sands, which are less extensive in the 

Chihuahuan Desert than quartzose sands. The microbiotic crusts are distributed in a patchy pattern 

reflecting microclimatic patterns of modified 

temperature, moisture, and soil erosion, which creates 

a habitat where the crusts can flourish. 

The roles of large herbivores and burrowing animals 

on patch dynamics and crust retention are being analyzed in an IALC study that has recently been initiated 

in Israel and the Southwestern United States. Information on plant consumption rates and preferences of 

animals and crust disruptions at varying animal densities will enable managers to optimize livestock 

stocking densities as a vegetation and water 

management tool. 

Patch manipulations can be a management tool to 

preserve productivity and diversity of the landscape, 

restore desertified areas, and increase their productivity 

and diversity. Patch manipulation involves either a 

change in the ratio between microphytic and macrophytic patches or the addition of human-made patches. 

Since the IALC-supported studies entailed manipulations that changed the ratio between microphytic and 

macrophytic patches, results of these studies provide 

predictions of how changes in patchiness could be used 

to manage productivity and diversity as discussed below. 

Harvesting shrubs in the Negev increases plantspecies diversity. High germination of the herbaceous 

plants on the patches and the interface soil mounds 

between the macrophytic and microphytic patches 

occurs without competing shrubs in the macrophytic 

patches. This promotes a relative increase in macrophytic and a decrease in the microphytic patches. 

Increases in macrophytic and decreases in microphytic 

patches result in increased in runoff. However, extensive scraping, which contributes to runoff, decreases 

ecosystem productivity and diversity. Scraping can also 

be a restoration tool when management wants to 

restore the successional species and create landscape 

mosaics. Although in the short term, herbicide use 

increases runoff, it is not recommended as a management tool to increase water-harvesting potential. Herbicides can lull microphytic communities and ~~~1st 

disintegration increases infiltration of water into the 

soil, which decreases runoff. Spraying herbicides also 

reduces ecosystem productivity and diversity. Most of 

the plants and animals are eliminated from sites sprayed 

with herbicides. 
Chapter 4 

Because soil mounds are crucial for annual plant 

germination and growth, and because annual plants are 

the major source of productivity in arid and semiarid 

ecosystems, the results ofthe IALC studies suggest that 

these ecosystems are slow to recover from disturbances. 

Disturbances, such as overgrazing by livestock or excessive firewood cutting, reduce the abundance of macrophytic patches. Shrubs should be maintained in the 

ecosystems to promote productivity and biological 

diversity. However, some shrub turnover increases the 

productivity and diversity of annual and perennial 

plants in macrophytic patches. 

A managerial problem that remains is how to determine the optimal amount of livestoclz grazing, firewood harvesting, and other interventions to maintain a 

desired ratio between macrophytic and microphytic 

patches. Knowing the optimal amounts will help to 

achieve site productivity, diversity, and water production. Nevertheless, these IALC studies are helpful to 

planners, managers, and decision makers contemplating rehabilitation efforts to improve the functioning of 

degraded arid and semiarid ecosystems. 

Increased Ecosystem Productivity and 

Species Diversity 

Ihowing how a species reacts to changes in ecosystem productivity through processes such as competition is essential to effective ecosystem management and 

conservation. Increased productivity typically decreases 

species diversity (Rosenzweig 1971, Elseth and 

Baumgardner 198 1, Bergon et al. 1990). Researchers 

in a recently initiated IALC study have proposed 3 

hypotheses to explain the declining phase of productivity patterns in the Sonoran Desert of the Southwestern 

United States and the western Negev Desert in Israel. 

The hypotheses are intertaxon competition, habitat 

heterogeneity, and intrataxon competition. However, 

the hypotheses provide conflicting predictions that are 

being explored experimentally in the study. 

Study 

The occurrence and relative abundance of ants, 

birds, and rodents depends on seed enhancement in 

their habitats. Directing seed enhancement for a single 

group is evident by changes in population abundance of 

related populations, changes in overall species diversity 

of that taxon, and lower populations and increased food 

of other taxa. To test the validity of these predictions, 

researchers in the Sonoran Desert are using electronic 

seed feeders to drop precise amounts of seed 30 minutes after sunrise for ants and birds, 30 minutes after 

sunset for nocturnal rodents, and 30 minutes after 

sunrise and 30 minutes after sunset for ants, birds, and 

rodents. Concurrently, researchers in the western Negev 

Desert have established 10 seed feeders on 5 

experimental plots--4 have manipulative treatments 

and a control. Seeds are dropped in the Negev using the 

Sonoran Desert schedule. The sunrise feeders drop 

seeds through meshed trays so that only ants have 

access and drop seeds from lifted trays so that only birds 

have access. When completed, these experiments will 

allow the researchers to evaluate the effects of increased 

seed enrichment on species diversity. 

Why species diversity is often low when ecosystem 

productivity is high remains elusive. However, the 

study is examining the mechanisms controlling species 

diversity by altering food supplies to 3 key components 

of desert ecosystem-ants, birds, and rodents. Understanding about these mechanisms should help managers avoid diversity declines and improve species diversity 

in changing desert environments. 

Habitat Fragmentation and 

Management of Ecological Systems 

The effects of human-caused habitat fragmentation 

on wildlife have been widely studied in forest ecosystems. Habitat fragmentation results in landscape patchiness that changes the habitat conditions for wildlife 

species (Morrison et al. 1992, Patton 1992). However, 

little is known about the patchiness and scale of the 

patchiness of wildlife habitat in arid and semiarid ecosystems. IALC supports studies that examine the influence of habitat fragmentation and patch alterations on 

communities of sexual Cnenzidophorus lizards inhabiting the Negev and Chihuahuan Deserts of Israel and 

the Southwestern United States. Lizards contribute 
Processes Enhancing the Management of Ecological Systems 

significantly to the hnctioning of these ecosystems 

because they occur in high densities, are predators of 

arthropods and prey for larger vertebrates, and are 

burrow diggers. 

Studies 

Studies include the impact on lizards when highly 

productive patches are added, how urbanization and 

desertification alter lizard densities, and the impacts of 

livestock grazing on the diversity and abundance of 

lizards. Why habitat fragmentation affects sexual 

Cnemidophorus lizards more than pathenogenetic species of the same genera is also being investigated. Direct 

observations, food-abundance analysis, and trap-releaserecapture techniques are used to assess small-scale 

habitat preferences, which reflect habitat fragmentation and alteration, urbanization, and desertification. 

Impacts for management of the ecological systems 

studied can be inferred from the preliminary findings of 

the species-level processes. The abundance of lizards is 

similar in both deserts. However, human disturbances, 

which include excessive livestock grazing, urbanization, and activities to restore desertified areas, resulted 

in a change in the lizard-species composition in both 

localities. While these disturbances did not significantly 

alter species richness, lizard densities decreased with the 

increase in soil compaction attributed to livestocli 

grazing. The density change likely results from the 

destruction of burrows or the inability of lizards to 

construct burrows in compacted soil. 

A follow-up IALC study is focusing on learning 

about the effects of habitat fragmentation on sexual 

Cnemidophorus lizards and associated ecological processes at both the community and population levels to 

gain a higher-order perspective. Results from the study 

should lead to a better understanding of the influence 

of human-caused disturbances on ecosystem functioning and management. The benefits and costs of current 

management ofthe ecological systems will be evaluated 

considering the effects on the indigenous fauna. 

Habitat alteration by human disturbances is a concern to managers of arid and semiarid lands. These 

alterations often lead to habitat fragmentation, which 

influence the sustainability of wildlife populations and 

other natural resources in the affected areas. It is 

important to understand how habitat alterations and 

fragmentation impact ecosystem processes at species, 

community, and population levels to properly manage 

these resources. The continuing study represents a 

contribution to achieving understanding. 

Soil Seed Banks in Rangeland Management 

The persistence of annual forage species under conditions of highly fluctuating temperature and limited 

moisture environments depends on soil-seed bank 

maintenance (Evenari et al. 1982, Kemp 1989, Maranon 

and Bartolome 1989). When annual forage is used as 

the primary production component on fragile arid and 

semiarid rangelands, knowing the extent that existing 

soil-seed banlis of annual forage species can be depleted 

without causing lasting negative effects on the production of primary biomass and biological diversity of the 

plant comn~unities is important. IALC supports studies 

to learn about the role of soil-seed banks in arid and 

semiarid rangeland management, the effects of soil 

bsturbances and vegetation dynamics on the seed banks, 

and the effects of livestock grazing on the germination 

of seed banks and the newly-recruited forage species. 

Studies 

Effects of livestock grazing on the composition of 

seeds in soil banks and plant recruitment were determined from sites in grazed and ungrazed exclosures in 

the Negev Desert. Germination of seeds comprising 

the soil-seed banlis was determined through laboratory 

tests in Israel-germination of artificial seed banlisand Utah-dormancy tests and hydrothermal modeling. Findings from the study indicated that the effects 

of livestock grazing on soil-seed banks and newlyrecruited plants are habitat independent (Perevolotslq 

and Seligman 1998, Sternberg et al. 2000). Livestock 

grazing changed the overall balance of the palatable 

and less palatable species of annual plants in the seed 

banks and in the resulting vegetation on the productive 

sites. However, livestock grazing did not affect the less 

productive sites. Effects of livestock grazing on the 

composition of soil-seed banlis and on the resulting 

vegetation also appeared dependent on the inherent 

habitat productivity. 
Assessing the relative importance of soil-seed bank 

components and soil disturbances in determining the 

diversity of annual forage species following small-scale 

soil disturbances in the Negev Desert is the focus of 

another study currently in progress. The seed-bank 

components studied are external seed rains from outside 

the soil disturbance, internal seed rains from seeds 

produced within the disturbance, and residual 

ungerminated seeds from previous years. Soil 

disturbances are sunken and raised mounds. The study 

emphasizes learning about plant density, species richness, 

and the equatability ofvegetation on disturbed patches. 

The number and abundance of species in the seed- bank 

composition, the microclimate and soil moisture regimes 

of patch-specific conditions, and the complexity of the 

seed banks relative components are the factors used. 

Initial results from the study suggest a rapid recruitment 

of dense populations of plants from soil-seed banks in 

the rainy season. However, there is little indication that 

high temperatures or light inhibits germination of seeds 

on top of exposed soil crusts. Seed dispersal and 

subsequent predication cause vegetation differences 

rather than differences among species germination 

rates. 

The objectives ofanother study concern the ecological 

mechanisms that regulate germination timing, the 

prediction of germination outcomes, and the effects of 

livestock grazing on soil-seed bank composition and 

outcomes. The effects of interannual variations in rainfall 

patterns on soil-seed banks, vegetation, and biomass 

production are being investigated (Allen 1999). 

Microenvironments that prevail in seedbeds during and 

immediately after rainfall events that favor or prevent 

germination are also being studied to determine the 

effects of intermittent moisture on germination and 

dormancy loss. Simulation models of seed dormancy 

and loss are being developed and refined to predict 

seed-bank germination on rangelands under livestock 

grazing. These models will be validated with data from 

the Negev and information from transplant experiments 

and artificial seed banks. 

Soil-seed banks are often the sole source of 

germination stock to sustain the rangelands for livestock 

production. However, livestoclz grazing causes shortterm changes in the relative balance of forage and nonforage species. Long-term changes are currently 

unknown. Knowing the occurrence and success of the 

germination of seed-bank components can lead to 

predictions of plant-species dominance in communities 

due to changing weather patterns. The introduction of 

plant species to enrich rangeland vegetation or attain 

other rangeland management objectives-for example, 

ecological restoration-must consider the presence, 

quantity, and quality of seeds in soil-seed banks, and 

their behavior following rainfall events of known 

magnitudes. Understanding the timing of germination 

for species comprising the seed banks can produce 

better decisions about locations that offer the greatest 

potential for achieving desired management results. 

Plant Invasion and Introduction Effects on 

Ecosystem Properties 

A major challenge facing the managers of arid and 

semiarid lands is arresting desertification and, when and 

where possible, restoring ecosystem productivity and 

diversity. However, effective and economically efficient 

methods to attain these management goals are difficult 

to implement because of inherent habitat heterogeneity and patchiness that exists at different spatial scales. 

Planned or unplanned plant invasions, and the effects of 

these invasions on indigenous fauna and fauna, compound the situation. IALC supports studies to learn 

about plant invasions on ecosystem fimctioning and 

properties. 

Studies 

Banner- tailed kangaroo rats (Dipodonzyr spectabilis) 

are mound- building heteromyid rodents that inhabit 

the desert grasslands ofthe Southwestern United States. 

Mounds built by these rats differ from their surroundings in vegetative and hydrologic features and soilnutrient contents (Best 1988, Best et al. 1988, Waser 

and Jones 1989). Active mounds are kept free of 

vegetation by activities of the rats and, therefore, the 

rats influence local vegetation (Anderson 1999). Researchers are modeling the role of these mounds as they 

pertain to the invasion of mesquite (Prosopis spp.) 

shrubs onto grasslands in the Chihuahuan Desert of 
Processes Enhancing the Management of Ecological Systems 

southern New Mexico. 0 bservational and experimental studies have been accomplished to formulate a 

predictive model in which the role of kangaroo-rat 

mounds is analogous to that of tree-fall gaps in patchdynamic models of forest ecosystems. The kangaroorat model promotes hypotheses that feeding the 

preferences of banner-tailed kangaroo rats affect local 

vegetation by retarding mesquite shrub encroachment, 

that kangaroo rats can suppress mesquite shrub establishment near active mounds, and that mesquite seedlings are established preferentially on abandoned 

mounds. The validity of these hypotheses is being 

evaluated in the study. 

The introduction of trees and shrubs to arid or 

semiarid landscapes to counter desertification can increase productivity of the planted area and create a new 

habitat type that could increase species richness. Researchers in another study are determining the effects of 

planting trees and of shrub invasions on biodiversity in 

arid and semiarid environments by examining the effects on predacious spiders. Spiders are abundant, 

diverse, and an integral part of ecosystem functioning 

because of their role as arthropod predators in the food 

chain. Spiders are also sensitive to changes in habitat 

structure and are easy to monitor. Studies on the effects 

of planting trees and shrub invasions on spider densities 

and species richness are underway. Researchers in Israel 

are comparing tree-planted or savannized sites to natural shrublands in the Negev Desert, while other researchers in southern New Mexico are comparing 

shrub-encroached sites with natural shrublands on the 

Jornada Experimental Range. The results of the comparisons will increase our understanding of the effects 

of tree planting and shrub invasions on a key species 

group and biodiversity in similar arid and semiarid 

environments. 

For more than a century, cheatgrass (Bromus 

tectorum), a winter annual that is native to western 

Europe, has aggressively invaded the sagebrush ecosystems of the Great Basin in the Western United States. 

Livestock overgrazing and occurrences of uncontrolled 

fire have propelled the invasion. Cheatgrass has dominated the widespread transformation from a diverse 

shrub-perennial steppe to annual grasslands (Mack 

198 1,1986). The phenology of the species temporally 

and spatially redistributes water and other resources on 

the invaded landscapes. The primary objective of a 

recently initiated study is to quantifp the ecosystemlevel consequences of cheatgrass invasions, and the 

effects of remediation practices on area- based energy 

fluxes and evapotranspiration. The hypothesis is that 

the postfire dominance of cheatgrass arrests natural 

plant succession in Great Basin sagebrush ecosystems 

by redistributing water and other resources in time and 

space. The focus on water is because of its overriding 

control on the reestablishment of native vegetation. 

Findings from these studies will increase our lu~owledge and understanding of the processes and effects of 

planned and unplanned plant invasions on ecosystem 

functioning, properties, and multiple-use management 

of arid and semiarid lands. Tree, shrub, and herbaceous 

plant invasions often cause a conversion from a vegetative community, such as desert grasslands, to a less 

productive shrubland. Knowledge of the causal mechanisms for these invasions, and how they affect local flora 

and fauna, contribute to sustainable ecosystem management for livestock production and to the 

sustainability of wildlife habitats. However, effective 

and economically efficient methods to arrest desertification and restore ecosystem productivity and diversity 

can be difficult to implement because of the inherent 

habitat heterogeneity and patchiness encountered at 

different spatial scales. 

Demonstration Projects 

Ecological Processes Enhancing Sustainable 

Livestock Grazing 

Raising livestock is a traditional land use in arid and 

semiarid region. Unfortunately, desertification is possible where overgrazing occurs and improvement of 

livestock-grazing practices on overgrazed rangelands is 

often recommended (Anaya-Garduno et al. 1994, 

Squires and Sidahmed 1998). Importantly, the improvements must be acceptable to the herdsmen's way 

of life and must be sustainable and compatible with 

other land uses. An IALC demonstration project has 

been initiated in Israel to instill in local Bedouin 
Chapter 4 

Increases in invasive shrubs on overgrazed rangelands in arid and semiarid regions reduce the 

capacities of these rangelands to sustain livestock production. 
Processes Enhancing the Management of Ecological Systems 

pastoralists an awareness and understanding of sustainable livestock grazing for long-term human and 

environmental benefits. 

A farm that serves as a research site to improve sheep 

production in typical Bedouin pastoral systems is the 

location for demonstrating the benefits of sustainable 

sheep grazing systems to students and educators, local 

pastorales, managers, and scientists. Sites have been 

established on the farm to represent the environmental 

aspects of the locale, factors controlling forage productivity, effects of livestoclz grazing on vegetation and soil 

resources in these habitats, and a Bedouin farming 

operation from a herder's perspective. Additionally, 

visitors to the farm develop an integrated model of the 

structure, function, and management of a Bedouin 

livestoclz- grazing system. 

Information about environmental parameters (meteorological measurements, runoff, and erosion patterns), 

vegetation characteristics (biomass, species diversity, 

and seed- bank dynamics), ecological features (changes 

in landscape mosaic, organic matter, and sediment 

flows across the landscape), and rangelandimprovement methods (mineral amendments and herd 

movements) on the first demonstration 4 sites is presented to so that participants can develop an integrated 

livestock-grazing model at the fifth site. The project is 

helping participants to understand the linkages between ecology and livestock-grazing management. From 

these linkages, participants develop a working model of 

the structure, function, and management of a Bedouin 

farm centering on livestock production. 

Livestock grazing is a way to economically exploit 

rangelands. However, improper livestock-grazing practices can cause rangeland destruction, particularly in 

potentially desertified ecosystems. In properly implemented and sustainable grazing systems, livestock are 

manipulated to meet a designated purpose, such as 

meat, milk, or hide production, for compatibility with 

other land uses. The demonstration project illustrates 

the benefits of properly implemented and sustainable 

livestoclz-grazing systems by teaching about the 

structure and function of livestock-grazing systems; the 

effects of climate, habitat, and livestoclz grazing on 

inherent vegetation and soil properties; the principles 

of sustained livestock management in ecosystems threatened by desertification; and the relationships among 

rangeland management, economic benefits, and 

human cultures in arid and semiarid regions of the 

world. 

Survivors in the Sand 

Increasing public awareness and interest in natural 

resources, and their management issues, is critical to the 

conservation, sustainable use, and management of arid 

and semiarid lands. The role of research and development and effective public education, involvement, and 

cooperation is also crucial to the success of planned 

interventions. IALC supported preparation and dissemination of a video called Sumivo~s in the Sand to 

help meet the above needs, and to bring IALC's 

educational role to its public and private cooperators. 

Media specialists from New Mexico State University 

and public and private land managers and scientists in 

the United States, Israel, and Australia helped to prepare the video. The nature of natural resources, and 

their management issues, in the Southwestern United 

States, the Negev Desert, and the Australian Outback 

have been documented in the video through on-site 

interviews and supporting film archives. Among the 

topics presented are land reclamation; consemation of 

water, endangered species, and other natural resources; 

and sustainable ecosystem management. The 1 -hour 

video focuses on prevailing management conflicts and 

concerns by presenting the perspectives of managers 

and scientists who daily devote their attention to 

ecological sustainability. 

Through its widespread distribution, Sumivourc in 

the Sand has received a high level of attention. Collaboration with IALC member institutions, their cooperators, and other organizations has led to widely viewed 

telecasts of the video in the 3 featured countries. The 

video was released to the Public Broadcasting System 

for distribution in the United States and the Israeli 

Discovery Channel and ABC for distribution in Australia. Additionally, the video has been distributed through 
Chapter 4 

the Smithsonian Teacher Training Program as a part of 

the Digital Desert Library. Events centering on the 

video's release were a focal point for public education 

and participation. Survivors in the Sand has won awards 

at the New Yorlz International Film and the Columbus 

International Film and Video Festivals. 

Survivors in the Sand had generated awareness of, 

interest in, and support for arid and semiarid land 

management issues and practices. The video provides 

insight to managers and other clientele on the potentials for conservation, sustainable use, and management 

of land, water, and other natural resources on arid and 

semiarid land. Survivors in the Sand also identifies 

approaches to land use that are precedent-setting in 

technology and social involvement. The video helps 

planners, managers, and decision makers understand 

the importance of supporting research, effective 

management, and public involvement in land 

stewardship. 

Special Initiative 

Biodiversity in Drylands: Research, 

Management, and Demonstration 

Arid and semiarid regions, collectively called drylands 

in the initiative, are undergoing accelerating changes 

due to land-use and climatic pattern shifts. The changes 

are affecting the distribution and abundance of species, 

populations, and habitats and the diversity of organisms 

within ecosystems (Hoelzstra and Shachalz 1999a). 

D~ylands are also experiencing accelerating changes in 

their biodiversity. To promote integrative and comparative research and management and to facilitate a 

network of demonstration center that focus on dryland 

biodiversity and its management, an international worlzshop titled, "Biodiversity in Drylands: Research, 

Management, and Demonstration Needs" was held in 

Israel in June 1999. The workshop brought ecologists, 

managers, and educators to the Negev Desert to foster 

effective interactions about biodiversity and the ecological complexes of biodiversity at the organism, ecosystem, and landscape scale. The role of a demonstration 

networlz in advancing biodiversity research and management was presented to participants as they visited 

study sites where management applications of the 

respective research efforts shown were considered. 

Papers on biodiversity, linlung biodiversity at the 

population and community level with ecosystem and 

landscape diversities, management of biodiversity, and 

applications of scientific and management knowledge 

on biodiversity in demonstrations were available to the 

participants (Blaustein Institute for Desert Research 

1999). Subsets of participants representing ecologists, 

managers, and educators reviewed and revised the 

papers for inclusion in the boolz Biodiversity in Drylands 

to be published by Oxford Press (Shachalz et al. forthcoming). The boolz will be a usehl reference to conservation, restoration, and ecosystem management 

personnel, students, and academics who are interested 

in advancing research, management, and 

demonstration of dryland biodiversity. 
Chapter 5 

Inventorying and Measurement 

Techniques and Monitoring 

Research and Development P rejects developed. Spectral reflectance measures made under 

several conditions showed that the spectral characterisInfluence of Plant Characteristics Determined tics of the phycobilins in the crust caused the higher 

by Remote sensing of Vegetative Communities reflectivity of soil crust in the blue region of spectral 

values. Analyses to determine whether high NormalSatellite imagery shows a contrast in the reflectance 

values from the Negev Desert side of the IsraeliEgyptian border to the Sinai side. Because the Negev 

has been managed under a conservation policy, while 

the Sinai has been open to livestock grazing and other 

plant harvesting activities. Therefore, the Sinai has less 

vegetative cover and a higher surface reflectance 

(Otterman 1974, 1977, 1981, Tucker et al. 1985, 

Holben 1986, Townshend and Justice 1986). However, the difference in reflectance values cannot be 

attributed solely to the differences in vegetative cover. 

One hypothesis is that microphytic (biogenic) soil 

crusts exhibit reflectance characteristics similar to lower 

(smaller) plants in the vegetative communities. An 

IALC study tested this hypothesis and developed a 

remotely-sensed optical index to detect the extent of 

microphytic communities on arid soils. Another study 

is analyzing the impacts of temporal variations in the 

character of higher (larger) and lower plants on the 

spatial variability of their reflectance values. 

Studies 

ized Difference Vegetation Index (NDVI) values are 

caused by microphytes, which cover rock and soil 

surface in undisturbed areas, indicated that the NDVI 

response of lower plants could be similar to higher plant 

responses. Using the spectral response of biogenic 

crusts, a spectral index was developed from a normalized difference between the red and blue spectral values 

of the imagery. The unique spectral features of cyanobacteria 

crusts were analyzed relative to the visible spectroscopy, 

near-infrared spectroscopy, and shortwave infrared regions of the spectrum in relation to bare soil (sand) 

under varying moisture conditions. Tlus analysis showed 

that when biogenic crusts are wet, their NDVI values 

can approach 30% and the phycobilin pigments in the 

crusts contribute to the higher reflectance in the blue 

spectra. Finally, the optical properties of the various 

microphytic crusts were also examined under wet and 

dry conditions and at a range of viewing angles. 

Additional vegetative indices, including the first 

derivative spectral index, soil-adjusted vegetation index, and the p erpendicular vegetation index, decoupled 

the influence of the soil background on the NDVI 

To determine the effects of biogenic crusts on satel- values from the photosynthetic signal detected on the 

lite- based spectral indices of surface reflectance, ground satellite imagery. All of the soil crusts showed increased 

measurements were made of the spectral reflectance of photosynthetic activities when wet. The result of all of 

mobile sands, biogenic crusts, and Artenzezia-a spe- the analyses in this study has been a better understandcies that represents macrophytic vegetative reflectance ing of impacts that soil crusts have on vegetative indices 

in the region. A diagnostic tool to identify cyanophyte obtained from satellite-sensed images. The hypothesis 

within soil crusts using remotely-sensed images was that soil crusts produce NDVI values that are similar to 
Chapter 5 

vegetation was verified. Using the spectral response of 

soil crust in the blue region, a soil-crust index was also 

developed to distinguish between high-order 

vegetation and soil crusts in desert ecosystems. 

The second study is dealing with the difficulties of 

temporal changes in the vegetation state and soil-rock 

signature used to discriminate vegetation from a soil or 

rock bacliground. These difficulties were encountered 

in the earlier study that attempted to detect and monitor temporal changes in vegetation along the IsraeliEgyptian border by multispectral imagery. Field- and 

satellite- based measures of surface reflectance obtained 

in rainy and dry seasons have been related through the 

Linear Mixture Model (Icholzu and Karnieli 1996) to 

estimates ofvegetation cover and densities from ground 

plots (McAuliffe 1990). This was done to estimate the 

overall spectral signal that higher and lower plants and 

bare surfaces reflected. Spectral responses are mixed by 

their percentage of cover to simulate the anticipated 

responses from the red and near-infrared spectroscopy 

spectral bands from satellite imagery from June 1995 to 

June 1998. NDVI values were calculated from the 

reflectance values from the satellite images and 

composites were made monthly. 

Analysis of field-based measures of surface reflectance shows that the high reflectance of bare surfaces 

observed in rainy seasons is similar to that in dry 

seasons. Reflectance of the biogenic crusts during the 

rainy season is similar to that of higher plants, while 

reflectance of biogenic crusts in the dry season is similar 

to that of bare surfaces. Using the field-based measures 

of reflectance, researchers calculated the relative contributions of the different surface components to the 

overall NDVI values. Analysis ofthe satellite data shows 

a significant spectral dfference between the Negev Desert 

and Sinai for the study period, with the Sinai showing 

much higher reflectance. Correlation analyses between 

NDVI values and rainfall show a relatively high level of 

variation in the NDVI values for the Negev throughout 

the year and higher rainfall amounts result in higher 

composite NDVI values. The NDVI values for the Sinai 

remain relatively constant throughout the year. 

The first study has resulted in a better understanding 

of the impacts that soil crusts have on vegetative indices 

obtained from satellite-sensed images. Results from 

these studies indicate that satellite- based remotelysensed information can identitjr significant differences 

in plant characteristics and vegetative communities on 

desert landscapes. Use of satellite images, with estimated responses of vegetative changes to climctic conditions, allow predicted and satellite- based NDVI values 

to be noted and eval~zated. This information helps 

managers detect disturbed areas on a landscape, determined the nature of the disturbance, and identifj. 

possible mitigation measures. 

Monitoring the Effects of Wildlife Herbivory on 

Vegetation by Remote Sensing 

A major cause of desertification is overgrazing of 

vegetation by livestocli, which cascades into losses of 

soil resources, plant productivity and diversity, and 

ecological functioning of the site. An approach to 

restoring desertified ecosystems is to replace the livestock with indigenous herbivores that are valuable to 

people. However, the effects of the replacement, or, in 

the case of the IALC study, the reintroduction of 

herbivores on vegetation and other rangeland resources, 

should be monitored to enable the appropriate adaptive management to proceed. The study was designed 

to analyze the effects on vegetative-cover richness and 

to predkct future effects of the initial decade of reintroduction of the Asiatic wild ass (Equus hemionus) to the 

Negev Desert using ground-survey methods. 

Livestocli were removed from large portions of the 

Negev Desert in the 1950s because their historical 

overgrazing had led to a decline in rangeland health and 

a preponderance of non-palatable plants. Attempts to 

fill the void in the Negev's herbivoiy led to reintroduction of the Asiatic wild ass-an inhabitant of the Negev 

Desert in Biblical times but extinct by the early 20th 

century-to the Central Negev Desert in the 1980s. 

The primary purposes of this reintroduction effort 

included restoring native fauna, ameliorating effects of 

moderate livestocli grazing on plant diversity, and 

promoting ecotourism (Safriel et al. 1999). The study 

was designed to analyze the effects of the initial decade 
Inventorying and Measurement Techniques and Monitoring 

of the animal's reintroduction 011 the region's plant 

cover, predict future effects by ground-suivey methods 

(McAuliffe 1990, Camargo 1993), and explore applications of remote-sensing technology to monitor these 

effects. The discussion here focuses on exploring remotesensing technology to monitor the reintroduction 

effects. 

Spring and fall LANDSAT 5 Thematic Mapper 

images for a wet and a diy year were analyzed. None of 

the vegetation indices calculated for the images, including the NDVI and the Transformed Soil Adjusted 

Vegetation Index, were significantly correlated with 

the mean plant cover for non-grazed and grazed study 

plots (Safiiel et al. 1999). Failure to detect differences 

between non-grazed and grazed conditions was attributed to the overall low ground cover relative to soil 

cover and variability in the rocky soil type. The situation 

caused a high noise-to-signal ratio that overshadowed 

the herbivory effects on plant cover. However, differences in vegetation indices found between seasons and 

years suggested that changes in plant cover due to 

rainfall patterns could be detected by remote sensing. 

The inability to detect small declines or other changes 

in plant cover will probably lessen the usehlness of 

remote-sensing technology in analyzing the effects of 

herbivores on the ecology of deserts or on sites subjected to desertification. Small declines in plant cover5% in a humid region-with a 50% plant cover, might 

be ecologically insignificant. However, the same decline in a desert that has a 15% plant cover can be 

ecologically significant. Safriel et al. (1999) concluded 

that the remote-sensing technology used in the study 

does not offer great promise in avoiding ground-survey 

methods to measure or monitor the effects of wildlife 

herbivosy in a desert or desert-like vegetation. 

Regional Indices of Global Climate Change 

Land-water interfaces of temporary and seasonally 

flooded wetlands are ecotones between upland and 

aquatic ecosystems. These areas could be highly sensitive to global-climate changes (Mitsch and Gosselink 

1986, Poiani and Johnson 1991, Stakhiv and Major 

1997). Freshwater wetlands are aquifer discharge or 

recharge areas and function as sinks for sediments, 

nutrients, and contaminants that flow off a landscape. 

Therefore, the fluxes of materials and energy through 

land-water interfaces are directly linked to upland processes. IALC supported a study to learn about the 

spectral reflections and biological integrity of landwater interfaces of seasonal wetland basins. Additionally, the study sought to link the observed changes in 

the conditions of the basins to regionalized climate 

changes. 

Relationships between ground and satellite measurements of seasonal wetland basins were established, 

differences in seasonal wetland attributes along an aridto-semiarid gradient were quantified, and changes in 

seasonal wetland conditions were linked to spectral 

signatures in a regional climate change scenario in the 

study. Ground measurements were made to describe 

the physical, chemical, and biological attributes for 

wetland basins along selected precipitation gradients in 

South Dakota and Israel (Troelsti-up 1999). Physical 

attributes measured at each basin were area, depth of 

inundation in the basin, and average annual precipitation. Chemical attributes included benthic organic 

matter, dissolved oxygen content, nitrogen species 

(nitrite, nitrate, and ammonium), total and dissolved 

organic phosphorus, and specific conductance. Biological attributes were occurrences and abundances of 

vegetation species, stem densities, dsy-weight biomass, 

and occurrences and abundance of invertebrate taxa. 

For each basin, satellite measurements of reflectance 

were estimated with LANDSAT Thermatic Mapper 

imagery. These measurements included greenness, 

NDVI values, and wetness indices. Correlation and 

regression analyses were done to define relationships 

between ground measurements and satellite indices of 

landscape conditions. 

Climate was the major factor governing the physical, 

chemical, and biological attributes of the wetland basins studied. A significant finding, however, was that 

several LANDSAT Thematic imagery indices were significantly correlated to several physical and biological 

attributes (Troelstrup 1999). For example, brightness 

values were correlated with annual precipitation, basin 
depth, substrate strata, specific conductance, nitratenitrogen ratio, vegetation-stem density, and biomass of 

the vegetation for wetlands in South Dakota. NDVI 

indices were correlated with the biomass of the vegetation for wetlands in both South Dakota and Israel. 

Much of the variability in the NDVI values was explained through a multivariate model of vegetation 

biomass, annual precipitation, and inundation depth of 

a wetland. 

Study results could be used to detect regional climate 

changes and to evaluate efforts to mitigate the effects of 

climate changes on freshwater-wetland basins. Climate 

changes occur over long periods. Therefore, the impacts of climate changes on local flora and fauna might 

be undetected for decades. Additionally, ground monitoring of physical, chemical, and biological attributes of 

a wetland basin as a change-detection technique is 

expensive. Consequently, only a few basins can be 

monitored to detect the level of changes required to 

produce statistically signif cant results. To detect the 

effects of climate changes on a regional scale reliably, 

the ability to analyze changes in the physical, chemical, 

and biological attributes of many wetland basins at the 

regional scale is desirable. The study showed that 

relationships exist among the physical, chemical, and 

biological attributes of wetland basins; the land-water 

interfaces that are sensitive to changes in the global 

climate; and indices from satellite images. The images 

can establish baseline attributes for wetland basins on a 

regional scale. Future satellite images can be analyzed 

to determine if significant changes in wetland basin 

attributes have occurred. This comparison provides an 

indication of regionalized climate changes that will help 

managers anticipate future terrestrial conditions and 

will facilitate development of effective management 

practices. 

Monitoring Large Rainfall and Runoff Events, 

Flooding, and Other Outlier Events in 

Remote Areas 

Monitoring the availability of water resources in arid 

and semiarid regions is critical to efficient land 

management and restoration efforts. However, in remote areas, frequent representative sampling of large 

rainfall and runoff events, flooding, and other outlier 

events is difficult and costly because of the extreme 

variability of the occurrence of these events. On large 

areas of many watersheds, encountering extreme or 

outlier events on one or more isolated watershed in 

sparsely monitored areas was more likely than on a 

single well-instrumented watershed (Renard 1970, 

Singh and Woolhiser 1976, Morin and Sharon 199 3). 

Identifying and analyzing data from these isolated 

watersheds could significantly reduce the time and cost 

of obtaining long-term data from a single instrumented 

watershed that might not represent the larger area. 

Researchers in several IALC studies have explored, or 

are exploring, the feasibility of developing methodologies to acquire, analyze, and document data obtained 

during large rainfall and runoff events and flooding 

events in sparsely monitored, remote areas rapidly and 

cost-effectively. 

The coastal plain of central Israel, the Negev Desert, 

and the Walnut Gulch Experimental Watershed in 

southeastern Arizona were the sites for most of the 

studies. Research at the first site centered on validating 

radar- based estimates of rainfall for a 400-lun2 area that 

is 30 lim south of Tel Aviv. For the large storm that 

occurred on November 29,1991, point measurements 

of the rainfall were obtained from 5 ground-based rain 

gages, wlile radar- based estimates ofthe rainfall amounts 

were generated for 1 1im2 grids across the study site. 

Ground- based measurements of rainfall calibrated the 

radar-based estimates of rainfall from this storm by 

using the Window Probability Matching Method 

(Rosenfeld et al. 1994). Comparisons were made between measurements of rainfall from the ground- based 

rain gages and estimates of rainfall obtained by applying 

the cahbrated Window Probabhty Matchmg Method for 

a series ofstorms fi-om November28,199 1, to December 4, 

199 1. While the Window Probability Matching Method 

has been successfully used elsewhere (Rosenfeld et al. 

1994), results from this study did not show it to be a 

superior than existing algorithms for estimating large 

rainfall amounts falling on remote areas. 
Inventorying and Measurement Techniques and Monitoring 

Another study applied the Window Probability 

Matching Method to calibrate radar- based estimates of 

rainfall to point measurements from ground-based rain 

gages. This was accomplished to obtain accurate information about the areal extent and intensity of rainfall 

events in central Israel during the rainy seasons of 1995 

to 1996 and 1996 to 1997. Thirteen tipping-bucket 

rain gages in a radial strip up to 80 lzm from a radar site 

at Ben Gurion Awport, near Tel Aviv, and 56 standard 

rain gages from the coastal plain to the Judea and 

Samaria Mountains collected the rainfall amounts. The 

rainfall amounts calibrated the radar data, which was 

collected at 1 lun2 resolution and 1-minute intervals 

during the rainfall events. By using the Window 

Probability Matching Method, accurate synchronization of the timing of rainfall to radar data was achieved 

with measurements obtained in the tipping bucket rain 

gages. Two large rainfall events were selected for analysis. The first storm of 45 mm of rainfall occurred in 2 

days -January 15 and 16,1997. The second storm of 

80 mm occurred in 3 days-February 21,22, and 23, 

1997. 

Study results show that the Window Probability 

Matching Method is only practical when enough 

recording-rain gages with 1 -minute recording capabilities, such as tipping bucket rain gages, are used with a 

well maintained and highly accurate radar system. 

Unfortunately, there were not enough recording-rain 

gages in the study and maintenance problems with the 

radar system were encountered. The results show the 

difficulties associated with obtaining accurate information on large-rainfall events in remote arid and semiarid 

regions. 

A recently initiated IALC-supported study is exploring the structure and dynamics of rainstorms that cause 

flooding in the Negev Desert. Researchers are developing a database of atmospheric and hydrologic conditions associated with previous flooding events, 

categorizing conditions associated with major storm 

events, identifying atmospheric processes at a scale that 

produces flooding, and developing predictors of regional flood occurrences. About the latter, ground 

truth and remote-sensing data will be integrated to help 

determine the structure and dynamics of meso-scale 

rainfall systems to search for recurring patterns that 

indicate interactions with terrain features. Mechanisms 

linking meso-scale structures to hydrologic efficiencies 

induced by the terrain features will be identified for 

specified watersheds. Based on this lznowledge, a set of 

predictors for flood occurrences will be developed and 

tested with independent data sets. 

Researchers at Walnut Gulch are focusing their efforts on the uncertainties associated with the indirect 

measurement of peak streamflow-discharges levels that 

represent large-runoff events and flooding. The Walnut 

Gulch Experimental Watershed encompasses 12 subwatersheds that contain meteorological and hydrologic 

monitoring stations. The sub-watersheds range in area 

from 2 to 15 0 1zm2. In one study, channel reaches near 

recording-stream gages on the sub-watersheds were 

selected as sites for the indirect measurement of peak 

streamflow-discharge rates. The 1993 monsoon season 

of July to early September-the study period-was 

unusually dry and only moderate streamflows occurred. 

Nevertheless, 4 independent runoff events that were 

large enough to obtain indirect peak streamflow discharge measurements occurred. The high water marks 

left after the cessation of streamflow were noted for 

each channel reach. Pealz-flow estimates were calculated from water surface profiles and post-flow channel 

geometries. Estimates of uncertainty associated with 

the indirect peak streamflow-discharge estimates were 

developed. Unfortunately, because the uncertainty 

analysis was based on only small runoff events, its 

extrapolation to larger runoff events and flooding is 

limited. 

By comparing the efficacy of the power-law radarrainfall relationships (Marshall and Palmer 1948) from 

the United States to those in Israel, researchers from 

the United States and Israel are attempting to improve 

the algorithms used when estimating rainfall rates from 

radar data. Additionally, researchers are developing a 

predictive methodology to represent rainfall and runoff 

on relatively small watersheds in arid and semiarid 

regions. The study sites are the Walnut Gulch 

Experimental Watershed and several small watersheds 

in the Negev Desert that are located within radar 

coverage from the Ben Gurion Arport. Data sets for 

rainfall and runoff amounts will be collected; groundbased and radar- based estimates of rainfall amounts will 

be made; and physiography, stream networks, 

vegetative cover, and land-use on the watersheds 
Chapter 5 

studied will be obtained. Once the information is 

assembled, rainfall intensities will be estimated from the 

radar data at various temporal and spatial scales with the 

power-law relationship. The Window Probability Matching Method (Rosenfeld et al. 1994) and other methods 

will determine the appropriate temporal and spatial 

scales of rainfall data. The scales can predict streamflows 

from storm events of differing intensities and durations. 

Watershed scales and characteristics will also be 

examined to determine if correlative relationships exist. 

Results from these studies are providing insight 

about how to estimate the character of large runoff 

events, flooding, and other outlier events on lands with 

little or no ground-based monitoring. While these 

results may not be applicable to a wider range of 

conditions than those studied, the methodologies developed could be expanded to accomplish this goal. 

Once hlly developed and tested methodologies are 

available, their applications could help managers implement land-use practices and mitigation efforts to minimize the risk to life and property from extreme 

meteorological and hydrologic events. 

Dust Emissions and Desertification Implications 

Loss of particles from soil surfaces by wind erosion 

can exacerbate desertification. Fine particles ( < 5 0 mm 

in diameter) removed from soil surfaces represent a 

disproportionately high amount of nutrient loss when 

compared with the loss from coarser soil grains (Zobeclz 

and Fryer 1986, McTainsh 1989, Offer and Goosens 

1990). Controlling the loss of soil particles is critical to 

maintaining the sustainability of arid and semiarid 

ecosystems. An associated environmental problem is 

the size and mass of the resulting concentration of 

airborne dust, which affects human health. Dust emissions also affect soil resources, the atmosphere, and the 

socioeconomic conditions of people living in affected 

areas. To develop a better understanding of the processes that govern dust emissions from dryland surfaces, IALC is supporting a study to collect baseline 

information on dust emissions with known precision 

through field measurements. The field measurements 

will enhance the predictive capability of the dust 

emission model previously developed by Berlzofslzy 

and McEwain (1994). 

Researchers are measuring dust emissions on the 

playa surface of Owens Lake, California, a site highly 

susceptible in late winter and early spring. This area is 

the largest single source of dust emissions in North 

America (Bach et al. 1996, Niclding et al. 1997). A 10- 

m suspended sediment sampling tower, with 5 aerosol 

monitors and 5 anemometers that are vertically distributed along the tower and a wind vane on the top, 

collects airborne dust during emission events (Gillies 

and Berlzofslcy 1999). The aerosol monitors are constructed to facilitate orientation with wind from any 

direction to obtain mass dust-concentration measurements. Particle distribution is measured with an optical 

counter during emission events. Saltation activity is 

monitored with 6 energy sensors in an array around the 

tower. Data are collected at 1-second intervals and 

averaged over 15 -minute intervals because of the unsteady effects of the airflow. 

Improved simulations of Berlzofslzy's and McEwain's 

(1994) dust emission model using physically-based 

descriptions of the relationship of wind speed to dust 

emissions, the response of the emissions to changing 

surface-roughness conditions during erosive events, 

and the evolution of the particle-size distributions of 

suspended sediments are being developed. This information is based on source data from the field measurements taken at Owens Lake. Although the study 

continues, more than 20 hours of data have been 

collected at Owens Lake during 33 hours of erosive 

events. These data sets have been assembled into a 

database to guide development and testing of the dust 

emission model. Many improved descriptions of dust 

en~issions have already been incorporated into the 

model, which can predict the change of wind components in the transition layer, friction velocity, the change 

of the aerodynamic roughness, and dust concentrations 

near the ground and at the top surface layer. A module 

that incorporates particle distribution of suspended 

dust into the simulation procedure has also been included to improve its predictive capacity. The Berlzofslzy 

and McEwain (1994) model is interactive and userfriendly. 
Inventorying and Measurement Techniques and Monitoring 

The study will provide an enhanced model to managers of areas susceptible to dust storms so they can 

obtain reliable simulations of the potentials for dust 

emissions from a minimal amount of input data on soil 

types, surface conditions, and wind characteristics. The 

simulations will allow people to plan and manage land 

uses that prevent or mitigate against hazards posed by 

dust storms better. The enhanced model will be used in 

a prognostic capacity to determine how losses in fine 

particles can vary as a function of climatic change, 

human forces, or combinations thereof that could lead 

to desertification. 

Monitoring Behavior of Ungulates by 

Acoustic Telemetry 

Wild ungulates interact and affect many human 

activities in arid and semiarid regions. As medium- and 

large-sized herbivores, wild ungulates influence ecosystem processes, thereby, attracting management attention (Schleidt 1980, Patric et al. 1982, Cohen 1986, 

Hodeler and Bullock 1997). A new technology for 

remotely monitoring the behavior of desert ungulates 

using sound is being developed in a recently initiated 

IALC study. Acoustic telemetry is a potentially powerhl means of accurately monitoring a wide range of 

behavioral patterns, especially those associated with 

feeding activities, ofwild ungulates and other mammals. 

An acoustic telemetry system is being tailored to fit 

desert mule deer (Odocoileus hemionus ereinzicus) in 

Southwestern United States and Nubian ibex (Cap~a 

ibex numiana) in Israel. Subjects will be equipped with 

microphone transmitters, and their sounds recorded by 

a suitable receiver-recording system for interpretation 

and analysis. Captive animal trials to test and calibrate 

the telemetry system in relation to the animals' behavior will be done first. Field tests with free-ranging 

animals will be conducted with desert mule deer in the 

Sonoran Desert and with Nubian ibex in the Negev 

Desert. Phases of this study include developing equipment to monitor sounds generated by captive and freeranging animals, assembling a catalog of captive deer 

and ibex activity-sounds and a video for interpreting 

recorded field sounds, developing field applications 

and refining the telemetry system with free-ranging 

animals in their natural habitats, and producing guidelines for management purposes and future acoustic 

telemetry applications. 

Once developed and tested, acoustic telemetry will 

enable remote monitoring of feeding activities and 

other behaviors of free-ranging wildlife ungulates in 

their natural habitats. Knowledge of food preferences, 

feeding times, and other feeding habitats is essential to 

manage arid and semiarid ecosystems for sustainable 

wildlife resources and other multiple benefits effectively. Acoustic telemetry is also a unique expansion of 

biotelemetry capabilities for research programs. 

Demonstration Project 

Information Visualization for 

Management of Arid Lands Vegetation 

When evaluating management options on arid and 

semiarid landscapes, managers are confronted with 2 

scale-dependent issues. First, relevant research conducted on small-scale and often homogenous plots 

must be extrapolated to larger, heterogeneous landscape management units. Second, the time scale of 

management impacts is commonly beyond the managers' abilities to replicate. For both issues, replications 

and statistical analyses help to ensure the desired precision at a particular point in time, but they do not 

necessarily represent the dynamics of the management 

unit. 

The goal of the IALC demonstration project was to 

measure landscape elements over a broad spatial and 

temporal scale to allow management models to incorporate data appropriate to specified scales in the decision-malung process. Use of an information visualization 

system to manage vegetation on arid landscapes was 

demonstrated. Broom snakeweed (GutiErrezia 

sarotbrae), a perennial non-forage plant found on 

rangelands of the Southwestern United States, was 

used for the initial demonstration. However, the tools 
Chapter 5 

developed are adaptable for many problems associated 

with management of arid and semiarid landscapes. 

Demons frafhn 

The initial phase of the demonstration project involved compiling a database of all available research on 

broom snakeweed. The database was linked to maps, 

aerial photographs, and other information to provide 

site-specific and management-oriented information that 

typifies the rangelands in southern New Mexico. Using 

2 software programs, PHOTO-CATALOG SYSTEM 

(PCS) and LINKER, which researchers at the Physical 

Science Laboratory at New Mexico State University 

(Haynes and Sanderson 1999) developed, the linkage 

was accomplished. PCS allows a user to capture, archive, 

and display images. Photo sets can be logically organized by physical location or set relationships in a time 

sequence using the program. PCS hnctions in standalone applications, or it can be used in with a database 

browser. LINKER permits the visual correlation of 

spatial or temporal data, such as photographs, satellite 

imagery, geographic information system layers, databases, and spreadsheets. 

The information visualization system shows how the 

above tools develop visual databases that traverse data 

sets in spatial and temporal domains. The system also 

demonstrates that these tools spatially and temporally 

connect related information in a format that is easily 

recognizable and tailored to a user's preferences. A 

demonstration disc has been prepared to show the 

ability of LINKER to connect to a wide range of 

information and computer software packages. 

Landscape-scale management models require information that is not easily obtained from small plots or 

linear extrapolations from time-dependent census data 

sets. In addition, the dynamics of ecosystem resources 

are not linear, and their rate of change is a hnction of 

many inputs. To overcome these problems, photographic databases from 1940 to the present helped in 

developing applications of the demonstrated information visualization system with broom snakeweed. The 

ability to couple historical information with the results 

of experiments conducted on a small scale at a specific 

point in time is a powerful tool that will help people 

understand the landscape changes that can result from 

different management activities. Based on this understanding, managers can select the best course of action. 

Managers, researchers, and others interested in viewing 

this demonstration can contact the IALC office at 1955 

E. 6'" Street, Tucson, Arizona 85719-5224, USA; 

ialc@ag .arizona. edu (emad). 
Chaper 6 

Synthesis of Accomplishments 

Thematic Summaries 

Soil and Water Resources 

Development and Conservation 

The inherent problems associated with soil and water 

resources affect sustainability and variability in arid and 

semiarid ecosystems. IALC addressed some important 

issues related to the development and conservation of 

these natural resources under different climatic 

conditions in the Southwestern United States, the 

Middle East, and Chile. Scientists from these countries 

have exchanged views and collaborated in research and 

development and demonstration projects to help make 

information available for improved resource 

management. To enhance the dissemination of 

information and data needed for research and 

demonstration activities to all stakeholders, IALC has 

supported outreach activities through publications, 

conferences, and training courses. 

IALC orients its research and development projects 

to soil and water resource development and conservation to help people understand what causes losses in soil 

productivity and to synthesize methods to reclaim soil 

and water resources. Results from these efforts have 

provided managers and land owners with ways to 

overcome existing or anticipated limitations in soil and 

water resources. The findings can be directed to local, 

regional or even global issues. The role and importance 

of arid and semiarid land soils in carbon sequestration 

are not fully known. Nevertheless, land management 

agencies are being pressed to report management impacts and strategies potentially usehl to offset carbon 

emissions. IALC research and development efforts near 

completion will contribute fresh insights and innovated 

analytical tools for addressing management impacts 

and strategies. For example, conserving fresh potable 

water for critical uses is an important water reuse issue. 

Managers, therefore, must understand the associated 

agricultural crop and environmental health rislis posed 

by the various types of water that can be locally available. Research has extended our knowledge ofphysicalchemical processes that lead to the contamination of 

soil and water systems. 

IALC demonstration projects are providing managers and the public with information and instruction 

about local, regional, and global conservation and 

sustainable use. Arid and semiarid soils and water 

databases, developed through the demonstration 

projects, are a critical resource and a common reference 

available to the international Web-based community. 

In the Middle East, a West Bank demonstration project 

that raised awareness about the hazards associated with 

mishandling pesticides and other agrochemicals, provided immediate benefits to people needing health 

protection. The integrated pest management technology presented by the same program improves the 

likelihood that crop production will continue to be 

efficient as dependence on agrochemicals is reduced. 

The Negev Desert savannization project gives managers an opportunity to understand the concepts from 

work that has received international recognition for its 

originality and contributions to the advanced theories 

of ecosystem fimctioning. Most notably, the demonstration shows that barren landscapes can capture sufficient soil and water resources to support and attract 

biodiversity, while also attracting and sustaining human settlement. 

Demonstration efforts supported by IALC also teach 

people in small communities along the ho Grande 

fiver between the United States and Mexico how to 

construct wetlands to reduce biological and chemical 

contaminants that pose serious rislis to human health. 

Short-rotation tree plantations provide a water treatment 

approach within the community's economic reach. The 
Chapter 6 

tree-plantation wetland approach will also stimulate 

economic development because there is a need for 

wood fiber, transportation infrastructure, labor, and 

capital. The project also demonstrates application of a 

model for public participation in environment and 

development decisions affecting rural communities. In 

the Southwestern United States, less than 1% ofirrigated 

agricultural cropland uses drip technology to conserve 

water. Low use of drip technology in the region 

continues despite improveinents in engineering 

technology, which eliminated or greatly reduced the 

problems that most farmers found objectionable. A 

demonstration project in New Mexico that is showing 

people how to use drip irrigation technology to produce 

a regionally important agricultural crop, is of interest 

among farmers who are facing water shortages. 

IALC sponsored an international symposium on 

sustainable water management and wastewater recycling. The symposium provided a forum for attendees 

to deliberate topics, such as the appropriate technologies for irrigation with fresh and saline water, use of 

sewage effluents in irrigation, and groundwater protection and management. Program directors and administers ofwater and wastewater facilities, irrigation districts, 

and other government activities related to sustainable 

water management from 30 countries attended the 

symposium. Attendees developed recommendations 

and presented strategies on policy and action plans to 

help integrate land and water resource management on 

arid and semiarid lands. Momentum generated by the 

participants in this symposi~un is continuing under the 

leadership of a steering committee. 

Land Use and Reclamation 

Understanding the effects of land-use practices on 

water transpiration by indigenous plant communities 

and assemblages of sensitive bird populations is a focus 

of IALC research and development projects. Fifty 

percent or more of the annual precipitation that falls on 

oak woodlands in the Southwestern United States and 

northern Israel is lost through transpiration. Increased 

transpiration following fuelwood cutting in the Southwestern United States-a historical land use in the 

region-is attributed to the many vigorous 

postharvesting stump sprouts. Usually, tree removal 

increases water yields. However, in the Southwestern 

United States, tree harvesting results in less available 

precipitation to recharge groundwater aquifers or to 

produce streamflow. Elsewhere, the presence ofwoody 

plants affects the occurrence and distribution of sensitive bird species in the Borderlands area of the Southwestern United States. Sites with less than 10% 

woody-plant cover have larger populations of upland 

bird species, while sites with less than 20% woody-plant 

cover support grassland bird communities. Mosaics of 

diverse plant communities that differ in composition 

and structure should, therefore, support the greatest 

bird-species diversity. Managers have proposed prescribed burning and alternatives in livestock-grazing 

intensities to obtain these desired mosaics. 

A major thrust of IALC research and development 

concerns developing computer-based systems to improve decision-malung processes for desert, grassland, 

wetland, and riparian ecosystem management in the 

Southwestern United States and Middle East. Managers of these ecosystems generally confront problen~s 

that involve several objectives. For example, minimizing the costs ofsome water management practices while 

maximizing forage production, with a set of objective 

functions that are subject to many constraints, such as 

limited funding, a restricted land base, and a requirement to satisfy the objectives within a specified period. 

Managers can effectively analyze the problems with 

decision-support systems, such as those developed by 

researchers supported by IALC. While the specific 

themes of these systems centered on habitat suitability, 

livestock stocking rates, and plant-water relationships, 

the decision-support systems developed are applicable 

to a wide selection of management topics. 

In this category, IALC demonstration projects are 

producing information in easily accessible formats for 

use by managers of arid and semiarid lands. For example, they have developed a database template for 

managers to build their own local database systems for 

planning and tool effective and environmentally sound 

livestoclz's management practices on public grazing 

lands in the Southwestern United States. The database 

systems help researchers validate predictive models of 

forage growth and use patterns, students and teachers 

learn about the ecological processes of livestoclz production, and decision makers select the best action 

from a set of alternatives. 
Synthesis of Accomplishments 

Because water supplies and inherent natural resource 

productivity are limited on arid and semiarid lands, 

IALC supports development of a Website to bring 

people field-tested data and other information from the 

Southwestern United States. Titled the "Sustainable 

Management of Arid and Senliarid Watersheds," the 

format of the site encourages learning and helps in 

decision-malung. The site incl~tdes topics, references, 

and an interactive learning package on watershed 

management practices. Researchers are expanding the 

technology transfer methods so that hydrologic, 

ecological, and economic data sets from the 

Southwestern United States will be available to 

researchers, managers, educators, and decision makers 

in other regions. 

IALC-sponsored workshops, symposia, and training 

courses have been organized and conducted about arid 

and semiarid lands manageinent and the effective 

management of impacted ecological systems; 

desertification in developed countries; connecting 

science with community actions to combat 

desertification; and mitigating the risks in planning for 

the conservation and sustainable use ofwater and other 

natural resources in arid and semiarid regions. IALC's 

research, development, and demonstsation agendas were 

reinforced and expanded during the 1994 conference 

and workshop on arid lands management (Fisher et al. 

1999, Hoelistra and Joyce 1999, Hoelistra and Shachali 

1999b). The accomplishments and contributions of 

IALC's scientific and technical programs reviewed in 

this publication are in response to this agenda. 

Sustainable management of watersheds in arid and semiarid regions is necessary to 

protect limited water supplies and retain natural resource productivity. 
Chapter 6 

Processes Enhancing Ecological Management 

IALC research and development activities help to 

determine how livestock grazing, tree planting, shrub 

occurrence and control, microphytic soil crusts occurrence, and burrowing animals are influencing plant 

diversity, nutrient distribution and productivity, and 

water capture. The high proportion of support for 

research and development projects relating to biological diversity and productivity of plants and animals, and 

their fimctional relationships, reflects the fragility of 

biodiversity in arid and semiarid land ecosystems. IALC 

has also funded research and development on genetic 

and physiological determinants of drought hardiness 

and the productivity of coniferous trees, fruit-producing 

cacti, and native populations of herbaceous plants. 

Results from the studies have provided a basis for 

selecting, breeding, and genetic modification of plants 

that tolerate aridity and heat. An improved understanding of genetic diversity and phenotypic plasticity of arid 

and semiarid land plants is helping to predict the effects 

of global climate change and habitat destruction on 

populations of plants and associated organisms. 

Research and development efforts supported by IALC 

have contributed to our understanding about how 

habitat fragmentation, livestock-grazing patterns, and 

shrub invasion effects species diversity and the ecology 

of desert lizards and arachnids. The important role of 

small mammals in soil-patch development and maintenance has also been clarified. Studies on ungulates 

focus on anti-nutritional factors in leguminous shrubs 

and development of telemetry to track animals. The 

effects of landscape-level processes, such as habitat 

fragmentation and desertification on ungulate and 

predator diversity and population dynamics, are research and development areas that have not been 

addressed. 

Less research and development have been focused on 

methods for ecosystem restoration, the effects of exotic 

plant and animal invaders, and impacts of recreation, 

mining, and military activities, and pollution on arid 

and semiarid lands. However, in the future, these areas 

will be likely be important. IALC has also been unable 

to support studies about cultural heritage preservation, 

including archaeological sites, and pastoral lifestyles 

and traditions. Research and development on these 

topics should be encouraged. 

An IALC demonstration project in Israel is focusing 

on sustainable livestock-grazing practices. The effort 

will help local Bedouins improve their grazing practices 

to sustain forage and livestock productivity near their 

settlements. Settlement patterns of the Bedouins have 

resulted in localized overgrazing of livestock that must 

be mitigated to ensure rangeland sustainability. Researchers, students, and agriculturalists from the Middle 

East and other arid and semiarid regions of the world 

visit this unique demonstration site to learn about 

environmentally sustainable livestock production. 

The video Sumivo~s in the Sand was televised to 

diverse audiences throughout the world and has received 

many awards. The video successfully delivers the IALC 

message and that of others concerned with the 

conservation and sustainable use of the natural resources 

on arid and semiarid lands. 

IALC helped to sponsored a conference in Beer 

Sheva, Israel, in June 1999 to promote integrative and 

comparative research and management of arid and 

semiarid ecosystem biodiversity. Ecologists, managers, 

and educators gathered to increase the effective interactions about biodiversity and ecological complexes of 

biodiversity at the organism, ecosystem, and landscape 

scale. They also formed a network of demonstration 

centers to advance research and management of 

biodiversity, and its ecological complexes. 

Inventorying and Measurement 

Techniques and Monitoring 

Assessment of the condition of arid and semiarid 

lands is an onerous task for land managers for many 

reasons. First, in arid and semiarid areas, management 

units are large and often cover a diverse array of 

ecotypes. In addition, subtle changes in a wide array of 

physical conditions can frequently result in long- term 

impacts on the sustainability of the natural and human 

environments of the land. The impacts include localized human disturbances, such as altering the composition of surface soils or denuding vegetation, and 

regional climate alterations, such as slightly reduce 

precipitation or increased temperatures. Finally, disturbances on arid and semiarid lands are long-termrecovery usually involves significant management inputs 

and it occurs over extended periods. Therefore, 
Synthesis of Accomplishments 

development of tools that can provide improved inventorying, measurement, and monitoring techniques are 

beneficial to managers. 

A variety of IALC-supported projects are focusing 

on developing improved ways to assess the risk that 

humans pose to the ecology of arid and semiarid 

environments, and the hazards that these environments 

pose to humans. Research and development projects 

that concern the impact of human activities on the 

environment, usually focus on the response of vegetative systems to livestock grazing and agroforestiy activities. For example, researchers have learned that 

field-based inventorying and monitoring is often unable to detect subtle changes in landscape conditions. 

Additionally, intensive inventorying and monitoring of 

small representative areas are not representative of the 

overall condition of the larger landscape. Therefore, 

techniques are needed to provide a wide spatial assessment of land surface conditions and to be comparable 

to temporal data sets that exist for decades or longer. 

Through IALC-funded efforts, researchers developed a variety of techniques to help accomplish the 

above goals. The primary technologies are based on 

developing algorithms for LANDSAT imagery. The 

algorithms were specifically tailored to assess vegetative 

and soil conditions in arid and semiarid regions. Methods to assess the conditions and capabilities of large 

land areas were also obtained. Since images are available 

from the 1980s, a large database exits to perform trend 

analyses about future assessment, planning, and management of arid and semiarid lands. 

IALC research and development projects about the 

risk to human health from arid and semiarid land 

environmental conditions focus on flood hazards and 

dust emissions. Meteorological events in these regions 

occur sparsely and randomly in space and time. Therefore, intensive inventorying and monitoring of selected 

drainage systems will probably not yield representative 

relationships between meteorological conditions and 

the hydrologic responses of drainages. Additionally, 

these efforts will not yield useful information about the 

frequency of large-runoff events that pose the greatest 

flood risk. Therefore, conventional flood-risk analysis 

techniques based on long-term stream-flow 

monitoring along with ground- based precipitation 

monitoring do not give managers the appropriate 

information to determine the risk of flooding. To 

overcome this difficulty, several IALC projects have 

examined using radar imagery with advanced watershed monitoring and modeling efforts to predict the 

occurrence and frequency of flooding events. The 

analysis techniques give managers the information necessary to prevent human development and habitation 

of areas that are prone to flood hazards. Additionally, 

the techniques give managers the ability to develop 

mitigation strategies for flood hazards in arid and 

semiarid areas. 

Although the research and development projects 

have produced useful management approaches and 

tools, the study results also provide inventorying and 

monitoring insight into future research needs on arid 

and semiarid lands. With increased sophistication in 

field- and satellite-based remotely-sensed technology, 

innovative analysis techniques are needed to process 

remotely-sensed data for application to arid and serniarid land management issues. Research and development efforts must focus on advances in remotely-sensed 

technology and synthesis of information through development of analytical procedures and predictive modeling. Research and development into the above areas 

will give managers ways to assess the condition of larger 

land areas using the same resources. Doing so will be a 

cost effective and reliable way to assess the condition of 

arid and semiarid lands. 

Other Comments 

IALC has discovered that to obtain research results 

with limited funding, it is necessary to foster collaboration between scientists and leverage the resources of 

major universities and experimental centers that focused on arid and semiarid land studies. Scientists and 

institutions with limited research resources benefit by 

collaborating on fimding policies. By investing in outreach, greater management impact is achieved than by 

focusing on research and development. Sustained efforts in research and development that relate to IALC's 

mission are often incubated at the research centers of 

IALC's member institutions. The centers are found at 

the Jacob Blaustein Institute for Desert Research; BenGurion University, Negev Desert; Sede Boker Campus, 
Chapter 6 

Israel; Jornada Experimental Range, New Mexico State 

University, Las Cruces; and the University ofArizona7s 

Santa hta Experimental Range south of Tucson. At 

these centers, it is possible to access land for research 

and demonstration projects, conduct long-term 

studies under protected conditions, and use an extensive base of historical research. Infrastructures and 

personnel at such established facilities are unique. Personnel often have an advantage when competing for 

grant funds because leveraging more research per unit 

of funding is possible due to the wealth of research 

resources that exist. The research centers are important 

to advance research about improving arid and semiarid 

land stewardship globally. 

Many planners, managers, and other practitioners 

are unable to access current research journals, reports, 

or personnel. They can, however, benefit from LALC's 

demonstration projects from funded research and development projects and related workshops, training 

sessions, and technology- transfer mechanisms. IALC 

efforts help link theoretical research to management 

applications using the interdisciplinary perspectives of 

biological, physical, and social scientists-people who 

are not usually involved in research and development 

projects. Additionally, IALC programs foster opportunities for communication and collaboration between 

theoretically-based ecologists and scientists in rangeland science, wildlife and watershed management, forestry, and related social scientists. Basic and applied 

research and development linked to application demonstration promotes improved land stewardship by 

identifying the roles of sustainable natural resource 

management on arid and semiarid lands and by recognizing the functioning of the environments7 critical 

ecosystem components. Understanding the importance 

of sustainable natural resource management is necessary for long-term human benefits and for the conservation and preservation of the natural heritage of arid 

and semiarid ecosystems. Ultimately, its contributions 

to the sustainability of arid and semiarid land ecosystems that support human settle will measure the success 

ofIALC-sponsored research and development projects. 
The Future 

Challenges 

IALC continues to provide unique opportunities for 

collaboration and creativity in basic and applied research and development. IALC experience confirms 

the importance of an external peer-review process to 

ensure that limited funds are spent efficiently and to 

maintain sponsor credibility. Fostering international 

collaboration has benefited researchers, students, and 

institutions through increased research innovation and 

productivity. Curiosity and self-interest drive researchers to pursue topics that are scientifically interesting, 

current, and likely to result in the dissemination of 

novel, worthwhile, and useful scientific findings. IALC 

successfully screens a diversity of research and development topics and, through its peer-review process, 

supports proposals of timely relevance. 

Where technologically- based economic development 

and urbanization supplants traditional pastoralism and 

other traditional land uses on arid and semiarid lands, 

problems of livestoclz overgrazing, ineffective water 

conservation, excessive recreation impacts, unwise mining operations, and pollution have emerged. These 

problems require careful research and planning to 

improve the balance between humans and their natural 

resource systems. Efforts to restore and preserve natural 

and cultural heritage, sustain intensive agricultural 

enterprises, and maintain biological diversity must, 

therefore, be increased. The consequences of overpopulation and resource degradation are dire and will 

challenge future political, economic, and scientific 

leaders. 

Research and development must continue to focus 

on critical issues. The results of research and development projects must be efficiently and effectively disseminated. IALC sponsors are interested in technology 

transfer to countries and regions with the greatest need. 

The importance of scientific and technical programs 

demonstration projects concerns IALC. However, more 

proposals have been submitted for research and development projects than for demonstration projects in the 

10-year history of IALC-perhaps reflecting a shortage 

of outreach educators. This disparity also reflects a 

trend in the privatization of outreach and development 

services that were, in the past, provided by government 

agencies. 

Transferring needed technology to arid and semiarid 

land managers and local landowners will remain a 

priority of IALC. Preparation and distribution of policy 

briefs and synthesis papers and other means of technology transfer, including technical training courses and 

workshops, are particularly useful to managers. Therefore, IALC should develop mechanisms to hnd these 

and other policy-oriented research and development 

projects that are useful to managers. Planning and 

managing to mitigate the conflicts and problems that 

occur at the urban and wildland interface also deserve 

increased attention. 

Options for Meeting the Challenges 

Future options for IALC include continuing to 

operate as in the past, periodically focusing on selected 

critical initiatives, increasing scientific and technical 

activities about the human dimension of arid and 

semiarid land stewardship, and emphasizing applied, 

adaptive, and other research and development efforts 

that have immediate management applications. Each 

option has advantages and disadvantages. 

This publication highlights some successes that 

IALC's scientific and technical programs have experienced during its 10-year history. IALC's peer-review 

process is a model for other similar programs funded by 
Chapter 7 

the U. S . Department of Agriculture. Funded proposals 

are recognized as practically and scientifically important by the best scientists in IALC-member institutions. 

Consequently, the portfolio of funded studies reflects 

national and international priorities for research, development, and application. Because of IALC's strengths 

and resources, limited grant money has often leveraged 

greater production than would otherwise be possible. 

Member institutions waive indirect cost reimbursement and make available research centers and personnel 

to support IALC programs directly and indirectly. 

IALC funding allows researchers to initiate innovative, 

new projects, or to add important elements to ongoing 

research and development projects, thereby, attracting 

proposals from a large pool of scientists. 

However, current scientific and technical programs 

have a maximum grant amount that is often insufficient 

to support graduate students at collaborating institutions. Because funding levels have not substantially 

increased, expanding the membership or scope ofIALC 

might be impossible. The limited size and special 

requirements of grants limit their attractiveness to 

potential applicants. Additionally, there are always fewer 

applicants for demonstration projects than for research 

projects, which limits the impact of IALC's scientific 

and technical programs. 

By periodically focusing on a single research and 

demonstration topic might help IALC to have a greater, 

more visible impact and a better-coordinated effort 

than under the current program. Because of the breadth 

of IALC's mission, the diversity of topics addressed 

annually is significant, which disperses the influence of 

the available funding over many problem areas. The 

disadvantages of this thematic approach include the 

possibility that IALC could have difficulty attracting 

many quality proposals from its member institutions. If 

the area of focus selected for emphasis is one in which 

some member institutions lack expertise, the institutions could leave TALC, or lessen their involvement in 

IALC's scientific and technical programs. If this were to 

occur, some of the best IALC scientists would not have 

the opportunity to guide IALC by submitting proposals that reflect their collective judgment and experience. 

A review of completed IALC projects provides only 

minor support for narrowing the program boundaries. 

Despite the challenges posed by de-facto requirements 

for multinational teams, diverse disciplines, researchers, 

developers, and demonstrators have made significant, 

often breakthrough, contributions. Under the existing 

framework, all IALC member institutions in the United 

States have participated in funded projects and the list 

of participating institutions in Israel, Jordan, and Egypt 

continues to grow. Most important, participation is 

based on each institution's capacity to direct its strength 

and unique assets for TALC projects. By overly constraining the solicitation process to arrive at a program 

theme, institutional participation would suffer, and the 

opportunity to expand the expertise and skills of IALC's 

best scientists, and their member institution's programs, would be lost. 

All arid and semiarid land problems are based on 

social and econon~iconditions. Therefore, the emphasis and integration of research, development, and demonstration into the human dimension of arid and 

semiarid land stewardship are important. Although the 

mission statement of IALC does not specifically address 

social science, IALC welcomes proposals on the human 

dimension of arid and semiarid land stewardship. Incorporating social science membership in IALC and 

clearly describing research and development priorities 

in these fields are essential. The need for socioeconomic 

assessments of research, development, and demonstration efforts is often apparent, but frequently laclung in 

IALC grant proposals. However, even without a high 

level of social science projects, the efforts of IALC cover 

a wide range of disciplines. To avoid greater dispersion 

of efforts and impacts and to expand efforts into the 

human dimension of arid and semiarid land ecosystem 

health and management, additional funding or changing IALC's scope is needed. 

Emphasizing research and development that have 

immediate management applications is a desire of both 

researchers and managers. Showing immediate practical benefits from IALC's scientific and technical programs would fulfill our social contract and justify our 

support. IALC's management-oriented clients would 

benefit in real time, and the benefits to society would 

accrue quickly. With more immediate successes, much 

needed direction and advice from managers would 

increase. Incorporating more dialogue and collaboration between managers and researchers will better serve 

the inhabitants of arid and semiarid lands. 

Many significant problems of arid and semiarid land 

stewardship require time, effort, collaboration, money, 
The Future 

and political action beyond the scope of IALC. Solutions to these problems require a mixture of basic and 

applied research and development from many organizations. IALC's scientists-especially junior scientistsmust conduct both basic and applied research or 

emphasize basic research or development in their personal portfolios to establish their institutional programs and succeed in their careers. Therefore, an 

emphasis on applied research might discourage some of 

IALC's brightest and most productive scientists from 

submitting grant proposals. In academia, applied research is not considered as prestigious as basic research 

and development, which is an attitude that must be 

overcome to attain an applied and adaptive focus in 

IALC's scientific and technical programs. 

The future will require IALC to be flexible and 

innovative. Policies and approaches that increase flexibility and foster innovation and collaboration must 

continue. IALC's members cooperate, collaborate, and 

contribute within a framework of shared interest in and 

concern for the viability of arid and semiarid land 

ecosystems worldwide. A framework that is supportive 

of member and client needs to generate support and 

address critical problems of arid and semiarid land 

stewardship better is essential to the continued success 

of IALC. 

Recognizing the human dimensions of natural resource management practices is 

increasingly important to effective arid and semiarid land stewardship. 

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IALC Funded Projects 1993-2000 

1993 

Research and Development Projects 

Arid Lands Water Resources Monitoring for Outlier Events on Ungauged 

Watersheds Using Radar Rainfall Measurements 

Collection of Cold-Tolerant Opuntia Fruit Clones in Northern Mexico and 

their Field Evaluation in Texas and Israel 

Propagation of Juniperus for Conservation Plantings 

Relationship Among Desert Patchiness, Resources, Production and Diversity: 

Implications for Rehabilitation of Desertified Environments 

Simulation of Selenium Discharge from Subsurface Drainage Systems 

Soil Salinization Induced by Runoff Collection in Small Forested Limans in 

the Negev Desert 

Transpirational Control in C,, C,, and CAM Plants 

Research and Development Projects 

Effects of Polyacrylamide on Infiltration of High-Sodium Water 

Effluent and Water Harvesting for Irrigation in Agroforestry Production 

Impact of Water Capture on the Dynamics of Plant Virus Vectors 

Patchiness and Nutrient Cycling in Arid Lands (U.S. and Israel) 

Role of Lower Plants in Remote Sensing ofArid Lands Vegetation Dynamics 

Demonstration Projects 

Design, Build, and Bring On-Line an IALC Component of the Arid Lands 

Information Network 

Planning an IPM Demonstration Project to Help Improve Water Quality 

and the Environment in the West Bank and Gaza 
Research and Development Projects 

Estimation of Areal Distribution of Rain Intensities ~JJ Radar and Rain 

Gauges 

Spectral Reflectance and Biological Integrity of the Land-Water Interface 

Water Use by Tree and Shrub Forms of Dryland Oaks 

Wildlife Rangeland Monitoring by Remote-Sensing of the Negev Desert 

Demonstration Projects 

Arid Lands Video Demonstration Outreach Project 

Information Visualization for the Management of Arid Lands Vegetation 

Research and Development Projects 

Capturing High Water-Use Efficiency in Cold Hardy Fruit Cacti 

Climate Change, Allometry, and the Hydraulics of Arid Land Trees 

Decision Support System for Arid Land Wetland and hparian Zones 

An Integrated Management and Decision Support System for Arid Lands 

Redistribution of Resources in Drylands of the U.S. and Israel 

Role of Seed Banks in the Management of Semiarid Rangelands Under 

Grazing 

Ruminal Manipulation to Modify Toxic Compounds in Leguminous Trees 

Southwestern Borderlands Grassland Ecosystem Restoration 

Demonstration Projects 

Developing a Sustainable Groundwater Management System from Decreased 

Nitrogen Use 

Developing a World Wide Web Resource on Aridic Soils of the U.S. and 

Israel 
IALC Funded Projects 

Research and Development Projects 

Disturbance, Seed Banks, and Vegetation Dynamics of Desert Annuals 

Drought-Responsive Genes in Plant Populations from Desert Habitats 

Effects of Habitat Fragmentation And Patch Alteration on Desert Lizards 

Effects of Polyacrylamide and Gypsum on Seedling Emergence 

Influence of Water Deficit on Gene Products in Pinus Halepensis 

Microbiotic Crusts: Their Nature and Establishment in Israel and New 

Mexico 

Demonstration Projects 

Savannization: Linking Ecological Understanding and Applications 

Management of Semiarid Watersheds: Technology Transfer 

Research and Development Projects 

Banner-Tailed IGngaroo Rats and Shrub Invasion in Desert Grasslands 

Effect of Redox Processes on Soil and Water Quality I 

Nitrogen, Productivity, and Soil Biota in the Chihuahuan and Negev Deserts 

Physically Active Soil Organic Matter: Key Factor in Arid Lands Reclamation? 

Predicting Seed Bank Germination in Semiarid Rangelands Under Grazing 

Management 

Remote Sensing Techniques Specific to Vegetation Detection in Arid 

Regions 

Demonstration Projects 

Forest Systems for Wastewater Treatment and Economic Sustainability 

Integrated Technology Transfer: Soil Management for Erodible Lands 

Savannization: Demonstration Project in Chile 
Research and Development Projects 

Atmospheric CO, Sequestration by Soil CaCO, in Jordan and New Mexico 

Dust Emissions from Drylands Implications for Desertification 

Effect of Increased Productivity on Species Diversity 

Effects of Habitat Fragmentation and Management Practices on Desert 

Lizards 

Influence of Savannization and Brush Invasion on Spider Diversity 

Water Use and Growth in Dryland Oaks: Effects of Coppice Thinning 

Demonstration Projects 

Improved Management of Public Land Grazing Allotments: An Information 

Resource 

Land Application of Wastewater for the Creation of Man-Made Forests in 

EWP~ 

Water Conservation through Drip Irrigated Alfalfa Cropping Systems 

2000 

Research and Development Projects 

Ecosystem Consequences of Cheatgrass Invasion in the Great Basin 

Effect of Redox Processes on Soil and Water Quality I1 

Factors Controlling Microbiotic Crusts: Negev and New Mexico 

Feasibility of Water Harvesting and Storage in Shallow Aquifers in the 

Eastern Badia of Jordan 

Monitoring the Behavior of Desert Ungulates by Acoustic Telemetry 

Radar Scaling and Runoff Prediction Models in Arid and Semarid Basins 

Soil Disturbance by Animals: Soil Genesis and Patch Dynamics 

Structure and Dynamics of Rainstorms Inducing Floods in the Negev 

Demonstration Projects 

Ecological Processes Enhancing Sustainable Grazing in Semiarid Ecosystems 

Management of Semiarid Watersheds - Phase 2: Decision-Malung Tools and 

Technology Transfer 

1 ROCKY MOUNTAIN 

The Rocky Mountain Research Station develops scientific information 

and technology to improve management, protection, and use of forests 

and rangelands. Research is designed to meet the needs of National 

Forest managers, federal and state agencies, public and private 

organizations, academic institutions, industry, and individuals. 

Studies accelerate solutions to problems involving ecosystems, range, 

forests, water, recreation, fire, resource inventory, land reclamation, 

community sustainability, forest engineering technology, multiple use 

economics, wildlife and fish habitat, and forest insects and diseases. 

Studies are conducted cooperatively, and applications can be found 

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Missoula, Montana 

Lincoln, Nebraska 

Reno, Nevada 

Albuquerque, New Mexico 

Rapid City, South Dakota 

Logan, Utah 

Ogden, Utah 

Provo, Utah 

Laramie, Wyoming 

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