U.S. Forest Service

Pacific Southwest Research Station

DEPAR TMENT OF AGRICULT URE

Serving California, Hawaii, and the Pacific Islands

©Michael Balint

2015 Accomplishments Report
I am proud to present the Pacific Southwest (PSW) 

Research Station’s 2015 Accomplishments 

Report. As part of the U.S. Forest Service, the 

station provides research that addresses 

contemporary questions about trees, forests, and 

ecosystems, and their relationship to people now 

and into the future. The scientific knowledge, 

expertise, and tools that our research station 

provides are instrumental in delivering and 

sustaining benefits from forests and grasslands in 

the United States and beyond. To frame our work, 

we have established four robust outcomes that are 

designed to provide and enhance forest resources 

and benefits that are important to the American public: (1) forest landscapes that are 

resilient to disturbance, especially fire; (2) enhanced benefits to urban communities 

from the natural environment; (3) clean and reliable water resources; and (4) sustained 

ecological resources and services. These outcomes represent lofty goals that can only 

be achieved through broad and strong collaboration with many governmental and 

nongovernmental entities. Our role is to conduct rigorous science that addresses 

research priorities in these areas. Our science is the foundation upon which successful 

policies and management can be implemented. The station has a rich and impactful 

history of conducting and delivering relevant science throughout California, Hawaii, 

and the Pacific Islands over the past 90 years.

Vision and Mission

The Pacific Southwest 

Research Station is a 

world leader in natural 

resources research 

through our scientific 

excellence and 

responsiveness to the 

needs of current and 

future generations. Our 

mission is to develop and 

communicate science 

needed to sustain forest 

ecosystems and their 

benefits to society.

Station Director’s Message

Current events, such as drought and wildfire in California, and threats from invasive 

species and disease in Hawaii, have brought an increased sense of urgency to our 

work. I’m encouraged by the developments I’ve seen over the last year within our 

station and among our partners to collaborate to find ways to make our landscapes 

more resilient. The highlights in this document demonstrate a few of the many ways our 

work is moving us closer to the four desired outcomes. None of this would be possible 

without the tireless efforts of our dedicated staff, and the numerous collaborators 

involved in our research nationally and internationally. Our station has many leaders, 

some of whom are mentioned within these pages; but many are not. I would like to 

dedicate this year’s Accomplishments Report to the diverse group of people – 

volunteers, collaborators, students, spouses and family, and students – who have 

contributed to our research, which has led to the impressive achievements presented 

in this report. Without you, none of this would have been possible! 

Alexander L. Friend, Ph.D.

Station Director, Pacific Southwest Research Station

About Us

The Pacific Southwest Research Station 

(PSW) represents Forest Service Research 

and Development in California, Hawaii, and 

the U.S.-affiliated Pacific Islands. Our region 

has the lowest, driest desert in the country, 

the highest elevations within the 48 

contiguous States, and the wettest tropical 

forests. An abundant diversity of native plants 

and animals and nearly half of the Nation’s 

threatened and endangered species live in 

this region. At PSW, we develop and deliver 

science to help inform decisions about 

natural resources management, and 

conservation. Much of our work is 

accomplished in cooperation with other 

research institutions, such as universities, 

state and other federal agencies.

Caspar Creek Experimental Watershed. (U.S. Forest Service/Sherri Eng)

Message from the Director, Vision and Mission
The mission of the U.S. Forest Service, a federal agency under the U.S. Department 

of Agriculture, is to sustain the health, diversity, and productivity of the Nation’s 

forests and grasslands to meet the needs of present and future generations. 

Established in 1905, the Forest Service: 

• Manages 193 million acres of national forests and grasslands.

• Shares responsibility, working in concert with state and local agents, for the stewardship of 

about 500 million acres of nonfederal rural and urban forests.

The Forest Service comprises several major branches that work together to manage the 

Nation’s forests and protect global forest resources:

• The National Forest System sustains healthy terrestrial and aquatic ecosystems while addressing 

the need for resources, commodities, and services. This system is divided into nine regions. 

• State and Private Forestry helps private landowners, state forestry organizations, tribes, and 

communities achieve forest management, protection, and utilization objectives through a 

wide range of cooperative programs in the State and Private Forestry mission area.

• Research and Development provides long-term research, scientific knowledge, and tools that 

are used to manage forests and rangelands across the United States and overseas. 

The Forest Service has seven research stations with research units located throughout 

the United States, Puerto Rico, and the Pacific.

• International Programs promotes sustainable forest management and biodiversity 

conservation internationally.

• Law Enforcement and Investigations enforces federal laws and regulations governing 

national forest lands and resources.

Forest Service at a Glance

The Forest Service at Work in the Pacific Southwest Region

California and Hawaii are located in the Pacific 

Southwest Region (Region 5) of the Forest Service. The 

Pacific Southwest (PSW) Research Station, 

headquartered in Albany, California, partners with 18 

national forests in California, and with State and Private 

Forestry programs throughout California, Hawaii, and 

the Pacific Islands.

Leaders of Region 5 and PSW Research Station have a 

common goal of retaining and restoring ecological 

resilience of national forest lands to achieve 

sustainable ecosystems that provide a broad range of 

services to humans and other organisms. Combined 

effects of changing climate and hydrologic patterns, 

unhealthy forests, and rapidly growing human 

populations are resulting in increasingly over-allocated 

and undervalued ecosystem services (especially 

water); a dramatic increase in large wildfires, floods, 

and insect and disease outbreaks; threats from 

terrestrial and aquatic invasive species; and a growing 

need to revitalize rural economies in California, Hawaii, 

and the Pacific Islands. Region 5 and PSW Research 

Station are facing these challenges together and 

through collaboration with external partners around 

watershed restoration and forest resiliency.

ROCKY

MOUNTAIN 

RESEARCH

STATION

NORTHERN 

RESEARCH 

STATION

INTERNATIONAL 

INSTITUTE OF

TROPICAL 

FORESTRY

R1

Northern

R2

Rocky 

Mountain

R10

Alaska

R5

Pacific

Southwest

R4 

Intermountain

R6 

Pacific 

Northwest

R3 

Southwest

R9

Eastern

FOREST

PRODUCTS

LABORATORY

FOREST

PRODUCTS

LABORATORY

SOUTHERN

RESEARCH

STATION

SOUTHERN

RESEARCH

STATION

PACIFIC

NORTHWEST

RESEARCH

STATION

PACIFIC

SOUTHWEST

RESEARCH

STATION

ROCKY

MOUNTAIN 

RESEARCH

STATION

R8

Southern

LEGEND

Pacific Southwest Research Station

Pacific Northwest Research Station

Rocky Mountain Research Station

Northern Research Station

Southern Research Station

Forest Service Regional Boundary

Station Headquarters

International Institute of Tropical Forestry

Forest Products Laboratory

PACIFIC 

SOUTHWEST 

REGION

National Forests and Grasslands

Modoc

Los Padres

Angeles San Bernardino

Cleveland

Sequoia

Sierra

Plumas

Tahoe

Eldorado

Stanislaus

Mendocino 

McClellan

Regional Facility

Regional

 Office

Six

Rivers

Shasta

Trinity

Klamath

Inyo

Lassen

Plumas

Lake Tahoe Basin McClellan Management Unit Regional Facility

Regional

 Office

Tahoe

Eldorado

Six

Rivers

Klamath

Shasta

Trinity

Mendocino 

Inyo

Sierra

Stanislaus

Lassen

Modoc

Angeles San Bernardino

Cleveland

Sequoia

Los Padres

Los Padres

Forest Service at a Glance
Pacific Southwest Research Station at a Glance

Scientists and staff of the PSW Research Station work across eight laboratories, 

12 experimental forests and ranges, and two research watersheds comprising the 

station’s facilities in California and Hawaii. Research is also conducted in more 

than 90 research natural areas linked to a nationwide system of nonmanipulative 

research, monitoring, and educational opportunities. Research is organized into 

five research units:

1. Institute of Pacific Islands Forestry

Scientists conduct tropical ecosystem research and technology transfer. Research furthers sound management, 

conservation, and restoration of grassland, forest, and wetland ecosystems and landscapes in Hawaii, Guam, 

American Samoa, Northern Mariana Islands, Marshall Islands, Micronesia, and Palau (see Pacific Islands map). 

2. Conservation of Biodiversity Program

Scientists conduct research on genes, species, habitats, landscapes, and the biological processes necessary to 

maintain diversity of organisms and functioning ecosystems. Research focuses on enhancing the conservation 

of plant and animal species and habitats, and the restoration and maintenance of native ecosystems.

3. Ecosystem Function and Health Program

Scientists examine forest function and conduct research to protect and preserve water, air, and soil 

resources while considering the effects of a changing climate, unpredictable precipitation, air pollution, and 

constant threats from insect pests and plant pathogens.

4. Fire and Fuels Program

Scientists conduct research on how fuel types and conditions affect fire behavior and how physical 

properties of fuels influence fire severity and intensity. Research includes decision-support models that 

analyze risk, resource allocation economics, and fire-danger forecasting. 

5. Urban Ecosystems and Social Dynamics Program

Scientists examine the interconnections of people and natural resources. Research focuses on developing 

knowledge and tools in natural resources management to better serve the public, and to connect urban 

dwellers with public lands through urban forestry and social science research.

Pacific Southwest Research Station at a Glance

WORKFORCE

• Total station workforce: 

228 employees

• Permanent workforce: 

156 employees

• Of the permanent workforce, 

41 employees (26.3%) are research scientists.

• In addition to the permanent workforce, 

9 employees are postdoctoral researchers.

• Temporary workforce: 

72 employees

FUNDING

WEB METRICS

• Number of users on the PSW Research Station 

website: 51,506

• Number of sessions on the PSW Research 

Station website 78,872

• Countries or territories users originated from: 

188

• Page views of PSW Research Station publications: 

14,567

• Number of followers on Twitter: 

1,682

PSW’s area of responsibility also includes six U.S.-affiliated Pacific Islands.

PUBLICATIONS and 

MEDIA METRICS FY12 FY13 FY14 FY15

Total Publications 267 403 175 112

Peer-reviewed journal articles 120 124 109 81

Media Mentions 32 43 24 65

Press releases 13 10 8 7

Northern Mariana Islands (U.S.)

MARSHALL ISLANDS

Guam (U.S.)

MICRONESIA (FSO) PALAU

American Samoa (U.S.)

Hawai‘i

Pacic Islands

Indian Ocean

Extramural funding received

Base research operations

Total funding

Funding shown by fiscal year in millions (US $)

2015

2014

2013

2012

2011

0 5 10 15 20 25 30

$22.70

5.1

17.6

$26.30

3.4

22.9

$23.80

2.2

21.6

$26.20

3.7

22.5

$29.00

5.3

23.7
Climate-ready trees planted, benefits evaluated

​Research forester Greg McPherson joined the Sacramento Tree Foundation, City of

Sacramento Parks and Public Works Departments and local volunteers to plant 24

trees along the Kohl’s Bike Trail in Sacramento, California. Two representatives of

each of the 12 species have been planted in four Sacramento parks and a control

plot at the University of California, Davis, as part of a 20-year study to evaluate the

drought tolerance, pest vulnerability, growth and survival of promising new species.

Local Scouts learn about forest genetics and earn badges

​On a cold winter afternoon, Girl Scouts of America Troop 12 received a

warm welcome from station scientists at the Institute of Forest Genetics

in Placerville, California. The fifth-, sixth-, and seventh-graders learned

about the history of the institute and early genetic studies, ongoing

research of white pine blister rust (WPBR), efforts to map the WPBRresistant gene, and more. The scouts earned their Trees merit badges

following their interactive learning experience.

Community Involvement 

Students convene to discuss 

forest restoration in the Sierra Nevada

​Research ecologist Angela White, in conjunction with the University of California,

Berkeley, facilitated a 2-day workshop on fire and forest restoration objectives for

coniferous forests in the Sierra Nevada. Twenty students from across the Nation

participated in a discussion on current threats to forest integrity and the impacts of

different forest management options on the economic, societal, and ecological

values of forested ecosystems. Workshop participants also visited the site of the

King Fire, which burned in the Eldorado National Forest in 2014, and discussed the

role of the Forest Service in meeting future challenges.

Volunteers plant “climate-ready” trees along Kohl’s Bike Trail in Sacramento. (U.S. Forest Service/Greg McPherson)

Girl Scouts of America 

Trees merit badge. Research ecologist Angela White leads a workshop on fire and forest restoration in the Sierra Nevada.

Community Involvement

Institute of Pacific Islands Forestry joins 

National Geographic BioBlitz

The Institute of Pacific Islands Forestry participated in National Geographic’s

BioBlitz, an event that brought students, teachers, and families together with

traditional ecological experts, scientists, and naturalists for exploration in the

Hawaii Volcanoes National Park. Staff members created and hosted the

interactive Biodiversity Challenge

game in which teams, totaling more

than 200 players, competed for

scoreboard fame as they worked

to keep the balance of a native

ecosystem intact.

Volunteers spruce up Richmond Edible Forest

​Station Director Alex Friend, Assistant Director Jane Hayes, and Northern Research

Station Assistant Director Hao Tran worked with youths and partners to weed and

clean up the Forest Servicesponsored Richmond Edible

Forest in Richmond, California,

as part of the Martin Luther

King Jr. Day of Service. The

Richmond Edible Forest project

received a More Kids in the

Woods grant and a USDA MLK

Drum Major for Service Award

in 2012. Partners include Urban

Tilth, the National Park Service,

Kaiser Permanente, and

local communities.

Students volunteer to clean up the 

Hawaii Experimental Tropical Forest

Institute of Pacific Islands Forestry staff and Laupa ̄ hoehoe Community Public

Charter School students participated in a day trip to Laupa ̄ hoehoe Forest, a unit

of the Hawai‘i Experimental Tropical Forest (HETF). As part of a school project

studying the effects of pigs in the forest, students visited a fenced exclosure that

demonstrates how fencing protects natural habitats, viewed the destructive

evidence of abundant pig populations, and helped remove invasive weeds and

old fencing material left prior to the establishment of the HETF.

Institute cares for the land 

and community at Ki ̄holo fishpond

​Scientists and staff from the Institute of Pacific Islands Forestry participated in a

cleanup day at Ki ̄holo fishpond, in an effort to give back to the lands on which they

do research. They removed nonnative overhanging kiawe and ironwood branches

and hauled the wood to a staging area to be reused. The Ki ̄holo anchialine ponds,

landlocked water adjacent to the ocean, are rich in history and tradition and provide

a sustainable food source for the Hawaiian community and critical habitat for rare

invertebrate species endemic to the Hawaiian Islands. The ponds are threatened by

exotic/invasive species introductions, coastal development, and habitat destruction.

School children from Kaumana Elementary hold their ecosystem 

(net) in balance as to not lose any of their native species through 

the holes. Game Master, Kainana Francisco (center), reads a Chaos 

Card instructing participants to jump once, disrupting the balance 

of their ecosystem and causing game pieces to fall through the net. 

(U.S. Forest Service)

The Nature Conservancy and Institute of Pacific Islands Forestry staff members wrestle with 

interlocking limbs of nonnative kiawe trees.

Wood debris is hauled from the shoreline to a 

staging area where usable materials 

(firewood, fenceposts, etc.) are made 

available to the community.

(L-R) Hao Tran, Alex Friend, and Jane Hayes worked with partners and community 

volunteers to care for the Richmond Edible Forest on Martin Luther King Jr. Day of 

Service. (U.S. Forest Service)
Recent Activities and Achievements at PSW’s Experimental Areas

For more than 100 years, research conducted throughout a network of experimental forests and ranges has provided invaluable 

information about forest health and change across the United States. The station’s 12 experimental forests and ranges and two 

research watersheds represent the diverse terrain, history, and culture of the west coast, Hawaii, and the U.S.-affiliated Pacific Islands. 

These living laboratories contribute a vast body of knowledge to guide land management decisions that can sustain forest ecosystem 

services and benefits in California, Hawaii, and beyond.

Drought affecting western pond turtle populations

The western pond turtle (Actinemys marmorata) is a Species of Special Concern in 

California and a candidate for federal listing. In 2006, the pond turtle population at 

the San Joaquin Experimental Range (SJER) in Madera County, California, was 

estimated at only 10 to 12 individuals and consisted entirely of individuals older than 

12 years of age. Following the initiation of invasive bullfrog (Lithobates catesbianus) 

control efforts, juvenile turtles have 

been seen in most years and the 

population appeared to be 

rebounding. Four years of drought 

have caused the stock pond that 

serves as their primary water source 

to dry up in late summer (2012 and 

2013) or to not form at all (2014 and 

2015); the latter has never been 

recorded at SJER since its inception 

in 1935. Station researchers 

observed high levels of turtle 

mortality during this period. 

Researchers observed extensive 

terrestrial movements and movement 

into new areas, both of which make 

the turtles vulnerable to predation 

and are considered high-risk 

behavior. Low precipitation and 

drought are likely to negatively affect 

the already imperiled pond turtle 

populations in California. 

Streamflow research debunks assumptions about effects 

of climate change on Sierra Nevada forests 

An important ecosystem service provided by national forests is high-quality surface 

water. Researchers have measured precipitation and streamflow in 10 headwater 

catchments on the Kings River Experimental Watersheds (KREW) since 2002, 

covering a range of wet and dry years. Knowledge of streamflow variability is 

necessary for land managers in determining how to best manage catchments without 

affecting other ecosystem services. Initial results indicate that the evapotranspiration 

(the conversion of water into water vapor) greatly exceeds the amount of water 

leaving the KREW catchments as streamflow 

(water available for downstream uses). Thus 

runoff ratio values (streamflow divided by 

precipitation) were mostly less than 50 

percent. Historically, this ratio increases by 3 

percent per 100 meters of elevation increase 

(i.e., there is less evapotranspiration and 

greater streamflow). Although average annual 

evapotranspiration decreased as elevation 

increased, no significant difference was 

found in the elevation patterns of 

evapotranspiration between wet and dry 

years. The current assumption is that as the 

climate changes, snow-dominated highelevation catchments will change to function 

like lower elevation catchments; however, the 

observed hydrologic response of cold, wet 

years compared to dry, warm years does not 

support that assumption.

The western pond turtle is a Species of Special Concern in California. 

(U.S. Forest Service) Research ecologist Carolyn Hunsaker measures stream temperature 

acidity and electric conductivity (a measure of water quality) at the 

Kings River Experimental Watershed. 

(U.S. Forest Service/Jose Canchola)

Recent Activities and Achievements at PSW’s Experimental Areas

New approach to forest restoration garners broad support 

A “variable-density thinning” study on 

the Stanislaus-Tuolumne Experimental 

Forest proved not only to be a valuable 

opportunity for learning about the 

ecological outcomes of thinning and 

prescribed fire treatments, but also a 

catalyst for consensus building. This 

thinning approach is designed to restore 

the variability that was historically found in 

these forests and has gained the support of 

both environmental groups and the timber 

industry. Station researchers were invited 

by the Yosemite Stanislaus Solutions 

collaborative group to give several 

presentations and tours of the study area. 

The group is interested in facilitating the 

wider application of treatments to prevent 

future catastrophic wildfires. 

Low rainfall leads to declining salmon populations 

in Caspar Creek

A 52-year record of streamflow and rainfall at the Caspar Creek Experimental 

Watersheds in northwest California was evaluated to identify long-term changes in 

the seasonality of precipitation and runoff in the 473-hectare (1,169-acre) North Fork 

and 424-hectare (1,048-acre) South Fork watersheds. Autumn rainfall and runoff 

were found to have decreased in recent decades. Periods of relatively high flow 

early in the wet season 

(November-December) are 

important for allowing coho 

salmon to move upstream to 

spawn in these watersheds, 

and a decrease in these 

fish-passage flows may 

contribute to decreased 

coho salmon populations 

along California’s north 

central coast.

Historical streamflow charts go electronic

Streamflow has been measured on the San Dimas Experimental Forest since the late 

1930s. Paper charts document stream discharge over time but are cumbersome to 

use for most practical investigations. Now these stream charts have been converted 

to electronic spreadsheets, allowing comparison and analysis for ecosystem 

disturbances including the hydrologic response to wildland fire and to management 

manipulations, such as vegetation type-conversion and prescribed burning. The 

records may also contain surrogate conditions for global climate change research, 

serving as a benchmark against which to validate current model outcomes. The 

dataset has also allowed the participation in a national cross-site comparison of 

experimental forest and range reference watersheds.

Understanding how forests have changed 

in northeastern California

In a unique study of sampling methodologies conducted in 1933 and 1934, a 

complete census was taken of all trees in a 10,000-acre forest at Blacks Mountain 

Experimental Forest in northeastern 

California. This included over a half million 

trees observed on 4,000 contiguous plots. 

With this information, station scientists were 

able to evaluate the effect of scale on forest 

variability. Historical observations showed that 

tree density decreased as scale increased 

from 2.5 to 500 acres across the forest. 

Similar patterns were seen when considering 

other metrics such as aboveground biomass, 

crown area, and average tree size. The 

scientists confirmed that 80 years ago, these 

forests had a higher proportion of pine and a 

lower stem density, but much higher levels of 

standing biomass than the current forest. 

Specifically, these stands historically had 

approximately twice the biomass on one-fifth 

the number of stems. Crown area percentage 

of trees was roughly half of what is observed 

in current forests. The metrics derived in this 

study can be used as guides by forest 

managers who are conducting restoration 

efforts at a wide variety of scales.

Research ecologist Malcolm North (center) explains the 

variable-density thinning approach to creating resilient forests to 

interested stakeholders and members of the media during a 

fieldtrip to the Stanislaus-Tuolumne Experimental Forest. (U.S. 

Forest Service/Eric Knapp)

Decreased streamflow may lead to decreased coho salmon populations along California’s 

north-central coast. (U.S. Forest Service)

Historical data on forest density can help guide restoration efforts. 

(U.S. Forest Service)
Institute of Pacific Islands Forestry

A center of research and technology transfer since 1967, the Institute of Pacific 

Islands Forestry addresses information needs to support the management, 

conservation, and restoration of natural forest and wetland ecosystems and landscapes 

throughout the Pacific. The institute’s area of responsibility includes the State of Hawaii 

and six U.S.-affiliated Pacific Islands: the Territory of Guam, the Territory of American 

Samoa, the Commonwealth of the Northern Mariana Islands, the Republic of the 

Marshall Islands, the Federated States of Micronesia, and the Republic of Palau. 

The focus of research and technological assistance centers on Hawaii and other islands 

of the Pacific, but results are applicable to many tropical and temperate ecosystems of 

the world, including the U.S. mainland. The research conducted through the institute 

encompasses the station’s four program areas.

The Hawaii Experimental Tropical Forest (HETF) is the first experimental forest in the 

Pacific Islands and directly contributes to a better understanding and conveyance of 

information about climate change, biological diversity, and ecosystem processes in the 

Pacific region and tropical ecosystems worldwide. The HETF encompasses remarkable 

gradients of climate, forests, soils, and resource history that allow station researchers 

and collaborators to address critical natural resource and conservation questions 

fundamental to effectively managing tropical forests to maintain and enhance important 

ecosystem services in a changing climate.

Institute of Pacific Islands Forestry Research focuses on the following areas:

• Increase understanding of invasive species 

interactions with factors including fire, disturbance, 

watershed management, and recreation.

• Assess water quality, food web structure, and 

fish and invertebrate assemblages in a number of 

watersheds to improve protection, management, 

and restoration of forested wetlands and water 

resources in the Pacific Islands.

2015 Research Highlights

Impacts of climate change on Pacific Island streams

Many climate models predict warmer and drier conditions 

throughout the tropics, yet it is unclear how this will affect 

tropical streams. Using a naturally occurring rainfall 

gradient along the north Hilo coastline of Hawaii Island, 

station scientists have been monitoring how streamflow 

and various ecological parameters from 12 streams will 

respond to changes in rainfall, streamflow, flow stability, 

and flashiness (the frequency and rapidity of short-term 

changes in streamflow in response to storm events) all 

declined with decreasing rainfall, while flow variability 

increased. Reduced streamflow resulted in a shift in 

invertebrate production, and lower algal growth, food 

quantity, and invertebrate fitness. For example, shrimp 

egg production fell with decreasing streamflow as did 

the timing and frequency of shrimp larvae.

Understanding the impact and spread of the Rapid ‘Ōhi‘a Death disease on Hawaii’s native forests

The ‘O ̄ hi’a tree is an ecologically dominant and culturally 

iconic native Hawaiian tree. It is the dominant tree species 

in 80 percent of Hawai’i’s native forests. Since 2010, a 

devastating fungal pathogen, Ceratocystis fimbriata, 

threatens to kill ‘O ̄ hi’a on Hawai’i Island and statewide. 

The Rapid ‘O ̄ hi’a Death (ROD) disease has shown to be 

highly virulent, spreading to over 6,000 acres with a 

mortality rate greater than 50 percent. Symptoms include 

blackening of wood, withered leaves, and tree mortality 

within 100 days. The demise of Hawai’i’s native ‘O ̄ hi’a 

forests would prompt a deeply devastating cascade of 

ecological losses that would affect native birds, insects, 

ecological community structure, and the culture and 

society of Hawai’i. Station scientists, working with several 

partners, including the USDA Agricultural Research 

Service, the University of Hawai’i, and the State Division 

of Forestry and Wildlife have conducted research to 

discover the nature of the disease, how it manifests itself, 

and what can be done to contain its spread in order to 

protect native forests.

Long-term fragmentation reduces ecosystem carbon storage and productivity

Forest fragmentation poses a great threat to tropical 

forests. Yet the long-term effects of fragmentation are 

poorly understood because (1) most effects require many 

decades to materialize, (2) the effects of edges on forest 

canopy structure as a function of fragment size are 

unknown, and (3) fragmentation studies are often 

confounded by various factors that are difficult to control. 

Station scientists quantified the long-term (centennial) 

effects of fragmentation on forest carbon storage, 

productivity and canopy structure using ground-based 

sampling and airborne light detection and ranging (LiDAR) 

of Hawaiian montane forest fragments ranging in size 

from 0.02 to 1000 hectares (0.05 to 2,470 acres), created 

more than 130 years ago by flowing lava. The scientists 

found that carbon storage in aboveground living biomass 

and in coarse woody debris declined dramatically with 

decreasing fragment size, as did stand productivity. 

Forest canopy structure varied strongly between forest 

fragment center and edge and between large and small 

fragments, with canopy becoming sparser in edges and in 

small fragments. Finally, nutrient return through litterfall 

declines as fragment size declines, indicating stronger 

nutrient losses from small versus large fragments. These 

changes caused by long-term fragmentation highlight the 

ecosystem benefits of maintaining large forested areas.

A Costa Rican butterfly may help control invasive miconia in Hawaii

Explorations in Costa Rica and Brazil have yielded several 

promising natural enemies of Miconia calvescens, an 

invasive tree that shades out native plants, which station 

scientists are now evaluating for use in Hawaii. Their strategy 

is to develop a suite of biocontrol agents attacking stems, 

leaves, and fruits of miconia, resulting in long-term 

suppression of the invasive tree. To date, the miconia 

butterfly (Euselasia chrysippe) is the most promising leaffeeding enemy. Euselasia eggs from Costa Rica were 

hatched and their caterpillars tested on a wide range of plant 

species from Costa Rica and Hawaii. Encouragingly, no 

sustained feeding occurred on any native Hawaiian plants 

while feeding was recorded on many Melastomataceae, the 

plant family of miconia. These data and observations of the 

butterfly in its native habitat indicate its host range is 

confined to M. calvescens and its close relatives. Given that 

all melastomes are alien in Hawai’i, this butterfly promises to 

help control invasive miconia in Hawai’i.

Rapid ‘O ̄hi’a Death is threatening Hawaii’s native forests. (U.S. Forest Service)

Airborne Carnegie Airborne Observatory-LiDAR image from a January 

2008 flight showing vegetation height for more than 100 kipuka (a 

place surrounded by lava, protected, and able to flourish) in the kipuka 

field system on the Island of Hawaii. Inset shows one example kipuka of 

roughly 25 hectares. (Carnegie Institution for Science/Greg Asner)

The introduction of miconia butterfly as a biocontrol could be used to 

manage the invasive miconia tree. (U.S. Forest Service)

Research ecologist Rich MacKenzie sets drift nets to sample larval fish and 

shrimp that are released to the water column. (U.S. Forest Service)
Conservation of Biodiversity Program

Miniature sensors reveal big news in bat ecology

The migratory patterns of bats between their summer and 

winter habitats have been inferred from limited existing data, but 

their actual migration routes and behavior remain largely 

unknown. Station scientists teamed with the U.S. Geological 

Survey, Bat Conservation International, and a veterinarian to 

pioneer the ability to attach global positioning system (GPS) and 

temperature/activity/light sensors to migratory hoary bats. The 

GPS tags revealed that some hoary bats regularly traveled 

farther than 50 kilometers per night, although flight directions 

were not predictable. One hoary bat traveled 130 kilometers in 

just one night, and 1000 kilometers in a single month. By linking 

activity and temperature data from the sensors with local 

weather data, the team discovered a new phenomenon in that 

one bat engaged in multiweek bouts of torpor during the winter. 

This project yielded new insights into bat ecology.

Conserving California’s hardwood ecosystems: The Valley Oak field trial

Valley Oak, a majestic California native oak found throughout 

California’s foothills, valleys, and flood plains, is under threat 

owing to habitat loss, low success rates, and climate change. 

In 2015, PSW Research Station, in collaboration with University 

of California, Los Angeles, established the first fully replicated 

field trial (provenance test) consisting of 600 seedlings 

representing 95 populations of valley oak planted at two 

separate sites in California (Placerville and Chico). This field 

trial represents a major accomplishment in the conservation of 

the species by creating a living conservation bank for the 

genetic diversity of valley oak, and establishing an invaluable 

scientific resource through the study of how each tree 

responds to different climatic conditions (such as temperature 

and precipitation), and what genetic characteristics are 

associated with trees that fare well and poorly under different 

conditions. The short- and long-term results of this work will 

help guide valley oak management, conservation, and 

restoration efforts throughout California.

Good news for the Point Arena mountain beaver

The mountain beaver has a restricted distribution in the Pacific 

Northwest due to its physiological limits to heat stress and 

water needs. The Point Arena subspecies is an endangered 

species and has an extremely small and isolated distribution. 

Station scientists sampled the occurrence of Point Arena 

mountain beavers to learn more about their range-wide 

distribution, predict the environmental features that best 

describe their occurrence, and establish a baseline for 

monitoring their distribution. Surveys yielded detection (and 

nondetection) locations that were used to develop a habitat 

suitability model by relating the locations to local environmental 

conditions. New detections expanded the known geographic 

range by over 50 percent, and well over a third of this expanded 

range was estimated to be suitable habitat. The identification of 

high-suitability areas through the range has moderated 

concerns about habitat loss and will allow land managers to 

prioritize areas for conservation and evaluate how a changing 

climate may affect the distribution in the future.

Scientists tracked the migration routes of migratory hoary bats. (Gabe Reyes)

Valley Oak seedlings at the Institute of Forest Genetics in Placerville, California. (U.S. Forest Service/Sherri Eng)

Point Arena mountain beaver. (U.S. Forest Service)

The station research area includes oceanic islands, 

elevational clines from coastal to alpine ecosystems 

in temperate and tropical ecosystems, and species 

and communities that occur nowhere else in the 

world. The area faces significant species local 

extirpations and extinctions, and wildlife habitat 

throughout the area continues to be threatened.

The Conservation of Biodiversity Program

provides high-quality, relevant information across the 

conservation continuum: status, threats, vulnerable 

components, response of organisms and 

ecosystems to threats, tradeoffs in desired 

management outcomes, efficacy of management 

approaches through adaptive management, 

restoration and recovery techniques and tools, and 

effectiveness monitoring and evaluation techniques.

Conservation of Biodiversity Research focuses on the following areas:

• Determine environmental conditions needed 

for terrestrial species persistence.

• Identify conditions that can support aquatic 

biodiversity and ecosystem services.

• Determine the genetic origins of traits that can 

enhance tree adaptability and utility. 

• Develop innovative approaches to reduce 

ecological impacts of nonnative species.

2015 Research Highlights 

Balancing act: Meeting the demands of fish and frogs in regulated rivers

Managing rivers with regulated waterflows (e.g., owing to 

dams or water storage) for both yellow-legged frogs and 

salmonids can be difficult as each species depends on 

specific temperatures and streamflows that if altered 

could significantly affect one species or the other. 

Specifically, frogs lay eggs in rivers in spring and depend 

on declining flows and warming temperatures for egg and 

tadpole survival and growth. Alternatively, salmonids 

depend on high spring flows and low-temperature 

reservoir releases to successfully move upstream to 

spawn. Station scientists built a model of how 

management of flow and temperature for salmonids can 

affect frog breeding success. Low-temperature releases 

were predicted to delay tadpole metamorphosis, which 

can reduce overwinter survival. Mitigating this impact 

through warmer reservoir releases was predicted to 

cause adult frogs to lay eggs before spring flow releases 

for salmonids, which would destroy the eggs. Land 

managers can use this model to inform how to manage 

regulated rivers to accommodate these divergent life 

history strategies.

Yellow-legged frog.
Ecosystem Function and Health Program

Using LiDAR to better map and estimate snags in forested landscapes 

In recent years, recognition of the essential roles 

standing dead trees (snags) play in forest ecosystems 

has significantly increased. Snags provide key habitat 

components for many threatened and forest-healthindicator species while also serving as key indicators of 

forest biodiversity. Unfortunately, assessing the number 

of snags is inherently difficult owing to their irregular 

and sparse distribution across the landscape. Most 

standard sampling designs are not efficient for rare 

events, such as snags, and thus require complex and 

expensive sampling procedures to produce sufficiently 

accurate estimates. To address this problem, a station 

researcher and collaborators explored and successfully 

developed a new method that uses remotely sensed 

airborne LiDAR (light detection and ranging) data to 

identify, map, and measure snags across the 

landscape. The method helps overcome the inherent 

difficulties associated with estimating and monitoring 

snags, while also providing snag stem maps that can be 

used to explore the spatial distribution of snags across 

the landscape.

Redistributing windrow topsoil enhances tree growth and alters understory species

Windrowing is a site-preparation operation that piles 

debris and shrub slash in linear rows. The process often 

displaces significant amounts of topsoil including 

nutrients and carbon into these linear rows. Although 

seedling survival and short-term growth may increase on 

account of the early control of competing vegetation, this 

practice can reduce long-term productivity, which affects 

the ability to restore forests. To test forest practices and 

productivity, station scientists studied the effect of 

redistributing windrowed topsoil on growth and 

development of ponderosa pine plantations. By 

redistributing about 18 centimeters of windrowed topsoil, 

stand growth increased significantly. Redistributing 

topsoil reduced understory woody plant biomass but 

significantly enhanced herbaceous biomass six years 

after treatment. The results of the study indicate that the 

negative effects of windrowing site preparation can be 

mitigated by carefully redistributing windrowed topsoil, 

even in an established plantation.

Quantifying impact of wildland fires on particulate matter in central California

As California’s climate warms and wildfires increase in 

frequency and severity, air quality regulators and land 

managers are becoming increasingly interested in 

understanding the impacts and spatial extent of smoke 

from wildland fire on air quality. Station researchers used 

real-time smoke data and statistical modeling to assess 

the contribution of smoke to surface fine particulate 

matter (PM2.5) levels. The study estimated between 27 

and 47 percent chance of a fire affecting ground-level 

particulate matter values, but only on days with high 

smoke density plumes above the site. The study also 

found that fires in most years and locations have no 

significant impact on compliance with current federal 

regulatory thresholds and that the majority of the PM2.5

pollution in the Sierra Nevada appears to be driven by 

human-caused emissions, rather than the episodic 

natural sources, such as fire.

Windrowing site preparation and planted seedlings or trees (A) and 54-year-old plantation (B) in which a 2012 

thinning for fuels reduction was conducted around the research blocks (five rectangular strips). Picture B is 

adapted from Google Earth.

Decaying snag providing a diversity of ecological functions. (U.S. Forest 

Service/Kelly Smith)

Ecosystem Function and Health Research focuses on the following areas:

• Determine how biophysical factors influence 

the function and productivity of tropical, 

subtropical, and temperate ecosystems.

• Quantify and predict ecosystem responses and 

adaptation to environmental stressors.

• Define and measure the impacts of biotic and 

abiotic stresses on hydrological and 

atmospheric systems.

• Develop models and tools, and evaluate 

management options for restoring, sustaining, and 

enhancing ecosystem function and productivity. 

2015 Research Highlights

Digging in the dirt: forest resilience found in soil

The Long-Term Soil Productivity Study (LTSP) was 

conceived in the 1980s by a consortium of U.S. and 

Canadian scientists. Recognizing that healthy soil is a 

prerequisite for the health of all 

forested ecosystems, the 

scientists designed and installed a 

common experiment at more than 

100 sites to test the resilience of 

soils and forests following 

moderate to severe disturbance. 

By 2015, most study sites in 

California had reached the 20-year 

mark, and the findings provided 

unexpected evidence of forest soil 

resilience and recovery. Diagnostic 

soil properties, such as carbon 

storage, nutrient content, root penetration, and water and 

air movement, did not differ dramatically among 

treatments, and, of equal surprise, differences in tree 

growth response were ordinary. These findings support 

the concept that 

soil functions 

can remain 

robust following 

a one-time forest 

harvest disturbance 

of considerable 

severity.

Field biologist Paul Renslow measuring 

soil greenhouse gases in a young stand 

in California, circa 1997. 

(U.S. Forest Service)

A severely compacted plot on the Long-Term Soil Productivity Study. 

Common treatments at installations across the United States and 

Canada include a gradient of soil compaction (none, moderate, 

severe) and organic residue retention (high, moderate, none). 

(U.S. Forest Service)

Location of study installations 

across the United States and Canada.

United States forests and wildland ecosystems are exceedingly diverse and provide a 

wide array of societal goods and services. From clean water, timber and non-timber 

products, and carbon sequestration to recreational use, aesthetic beauty, and native 

biodiversity, these ecosystems are national treasures that contribute to the prosperity 

of current and future generations. A growing list of environmental pressures, including 

climate change, insect outbreaks, water scarcity, and an increasing human population, 

threaten the health and integrity of these ecosystems. 

The Ecosystem Function and Health Program focuses on the interactions 

among changes in or brought about by biotic and abiotic factors, such as 

temperature and precipitation, invasive species, air pollution, insects, pathogens, 

and past and current land management actions. Station scientists conduct 

research that provides an integrated understanding of the biophysical conditions 

that threaten ecosystem resilience, including how environmental changes are 

initiated and progress, what thresholds are associated with these changes, and 

what the consequences are of crossing identified thresholds. 

LTSP Network

Core sites

Affiliated sites
Managing fire and the vegetation conditions that fuel fire is a paramount 

challenge to land managers throughout most of California, Hawaii, and the 

U.S.-affiliated Pacific Islands. The mission of the Fire and Fuels Program

is to provide scientific findings that will improve management actions intended 

to enhance resiliency and sustainability of wildland ecosystems affected by fire, 

and reduce the potential for adverse effects resulting from wildland fire, 

including loss of life and property.

Fire and Fuels

2015 Research Highlights

Fuel loads vary with overstory in a fire-excluded Sierra Nevada mixed-conifer forest 

Understanding fuel loads is critical to research and 

management in forests with altered fire regimes. Fuel 

loads are difficult to measure because of their variability, 

but a better understanding of fuel bed characteristics can 

aid in evaluating fire behavior and effects. Overstory 

(canopy) forest structure and composition, which are 

easier to measure than fuels, would be expected to 

influence fuel accumulation. To assess this, station 

researchers used intensive tree and fuel measurements in 

a fire-excluded Sierra Nevada mixed-conifer forest to 

build predictive models that relate overstory structure and 

composition to surface fuel. Overstory variables, such as 

canopy cover and tree species, explained between 16 and 

29 percent of the variation in fuel load. Greater canopy 

cover and white fir abundance were associated with 

greater fuel loads, while greater pine abundance was 

associated with lower load of fine woody fuels and greater 

load of litter. Knowledge of relationships contributing to 

variation in fuel loads increases our understanding of fuel 

accumulation and improves our ability to anticipate 

variability in fire behavior and effects.

Accumulated forest fuel at the Stanislaus Tuolumne 

Experimental Forest, during a prescribed burn in 2013. 

(U.S. Forest Service/Eric Knapp)

Research focuses on the following areas:

• Improve measurement, modeling, and 

prediction of wildland fire and weather 

phenomena in complex landscapes and fuels.

• Determine the ecological effects of fire and fire 

removal on landscapes throughout California, 

Hawaii, and the U.S.-affiliated Pacific Islands.

• Evaluate the short- and long-term outcomes of 

fuels, fire, and postfire management strategies. 

• Determine and quantify the interactions 

between climate, vegetation, and fire in the face 

of a changing climate and improve our 

understanding and predictability of these 

interactions in order to manage forests and 

wildlands more effectively. 

• Describe and quantify uncertainty and risk in a 

science-based decisionmaking framework for 

fire and land management planning.

Fire and Fuels Program

Paleoclimate fire history study reveals that humans have greater affect on forest ecosystems 

Station scientists studied two low-elevation lakes near 

prehistoric American Indian villages. Former paleoclimate 

studies in the region assumed that the fire regime was 

primarily influenced by climate alone. However, the PSW 

Research Station study indicates that despite having 

similar climate histories, the two lakes have differing fire 

regimes and associated vegetation over the last several 

thousand years. Lake basin size, sediment deposition 

rates, distance from human habitation sites, coastal 

influence, regional precipitation, and human influences 

on local fire regimes are likely responsible for the 

differences between the two lakes. Climate has been 

viewed as the dominant determinant of vegetation 

structure and composition change over time, but 

ethnographic and anthropological evidence suggest that 

Native American land use practices (i.e., fire use) had 

significant landscape effects on vegetation. This research 

highlights the importance of using multidisciplinary 

methods to investigate the potential affects that climate, 

prehistoric, and early historic American Indian fire 

management, as well as the effects of fire exclusion, have 

on forest ecosystems.

Historical data yields insight into structure and fire in ponderosa pine and mixed-conifer forests

Station researchers, with collaborators from the University 

of California, Berkeley, analyzed historical timber survey 

data collected in 1911 in the Stanislaus and Sequoia 

National Forests. The analyses showed that historical 

forest structure was very open, but highly variable. A 

comparison of the Sequoia National Forest data from 

1911 to current forest data found that forests have 

changed drastically, particularly in tree density, with 

increased small tree density and decreased large tree 

density, canopy cover, dominance of white fir in 

mixed-conifer forests, and the similarity of canopy cover 

in contemporary ponderosa pine and mixed-conifer 

forests. The 1911 data suggest that fires did not 

historically result in large patches (40 acres or more) of 

stand replacement, as commonly occurs in contemporary 

wildfires. The results of this study will 

inform restoration efforts in Sierra 

Nevada ponderosa pine-mixed conifer 

forests.

Thermal breakdown of forest fuels affected by how they are heated

Wildland fire results when the gases released by heated 

forest fuels ignite. Current fire tools do not explicitly 

model the pyrolysis process (chemical decomposition of 

compounds caused by high temperatures) in which 

physical and chemical changes occur to produce 

gases. A station researcher and partners examined the 

importance of modeling chemical reactions in pyrolysis of 

a fuel exposed to radiant (flame) and convective (hot gas) 

heating. Factoring in the chemical reactions reduced the 

amount of time before the fuel ignited, producing a more 

realistic result. The type of heating (radiant or convective) 

also affected the amount of time required for the gases to 

ignite. The results demonstrate the importance of 

chemistry in wildland fire spread and underscore the 

value of studying other forest fuels for an accurate 

understanding of wildland fire behavior.

Research ecologist Frank Lake shows Ukonom Hotshots the desired fire 

scars on stump sample. (U.S. Forest Service)

Historical photo of a 

“characteristic well-timbered 

region” near the Silver Fork of 

the American River in the El 

Dorado National Forest in 1899. 

(UC Berkeley Forestry Library)

Simulation results suggest that 

convection and radiation can 

have a significant effect on 

pyrolysis of woody fuel particles.

Radiation

Internal Radiation 

and Convection

Convection

Pyrolysis - gases, 

moisture, char 

Combustion

Leaf

Net

Radiation

Net

Convection
Devil’s Slide hiking trail in the San Jacinto Wilderness. (U.S. Forest Service/Jose Sanchez)

The interconnection between humans and nature is 

complex and enduring. People need and yearn for 

the resources that only nature can provide: clean 

water, clean air, natural scenic beauty, and a 

connection to the land and wildlife. The PSW 

Research Station strives to maintain forests, sustain 

functioning ecosystems in urban and wildland 

areas, enhance and protect quality of life, and 

ensure benefits to society through interdisciplinary 

research that examines urban ecosystems and 

social dynamics of natural resources conservation, 

management, and restoration.

The Urban Ecosystems and Social Dynamics 

Program conducts research and communicates 

science needed to understand and enhance 

the interconnections among ecosystems, 

people, and societies. 

Urban Ecosystem and Social Dynamics

2015 Research Highlights

Determining the impact of wildfire on recreation values

To determine the recreation value of the San Jacinto 

Wilderness in southern California, station researchers and 

partners analyzed and assessed survey data from 

backcountry visitors recreating in the area. Results of the 

analysis suggest that the recreation value of some hiking 

trails can be substantial. Should high-intensity wildfires 

completely close wilderness trails, the total recreation 

loss is estimated at $3.7 million. These findings can help 

managers plan more efficient fire management strategies 

and reduce potential losses from wildfires and other 

catastrophic disturbances. This may reduce 

environmental and social costs and thus enhance 

conservation of the resources.

Research focuses on the following areas:

• Determine the relationships among human 

uses, human values, ecosystem services, 

and management. 

• Ascertain the roles of changing demographics, 

urbanization, socioeconomics, and technology 

on use and sustainability of natural resources. 

• Examine the impacts of public policies on 

ecological and social patterns and processes 

along rural-to-urban gradients.

Devil’s Slide hiking trail in the San Jacinto Wilderness. (U.S. Forest Service/Jose Sanchez)

Urban Ecosystems and Social Dynamics Program

Young filmmakers bridge divide between urban youth and public lands

Researchers from San Francisco State University (in 

cooperation with PSW Research Station) explored young 

people’s relationship with, and views of, the outdoors 

through the use of social media and youth-driven 

messaging. Twenty-four young people produced short films 

and music videos about what the outdoors means to them 

for the Zoom In 29: Outside Your Door video project. The 

young filmmakers produced the project through BAYCAT, a 

San Francisco nonprofit that educates, empowers, and 

employs underserved youth and young adults in digital 

media. Three primary goals drove the direction, 

methodology, and analysis for the study including: 

understand how to effectively reach diverse urban youth by 

identifying appropriate media; 

develop sample key messages 

for diverse urban youth regarding 

urban and rural forests about 

topics of interest to adolescents; 

and evaluate the effectiveness of 

these media messages with a 

variety of urban youth. Youth 

were inspired through 

engagement in the program, and 

remain involved as they seek to 

positively transform their 

communities.

How green is the “green” industry?

While planting trees removes carbon dioxide (CO2) from 

the atmosphere, the heavy equipment and vehicles used 

to maintain them may release more CO2 per year than 

other similar-sized industries in the service sector. A 

study conducted by a station researcher and partners 

examined whether CO2 stored over 50 years by a 

California sycamore tree planted in Los Angeles is greater 

than emissions associated with different practices for 

producing, planting, pruning, watering, removing, and 

disposing of the tree. In Los Angeles, where irrigation 

water demand is great, CO2 emissions from irrigation 

accounted for 10 to 17 percent of the CO2 stored in the 

tree. Converting the wood from the removed tree into 

wood products delayed CO2 emissions for many years, 

accounting for 25 percent of the CO2 stored in the tree. 

This amount was substantially less than emissions from 

converting the wood from the removed tree into 

bioenergy (70 percent) or mulch (79 percent). Emissions 

from vehicles and equipment accounted for less than 1 

and 4 percent of CO2 stored in the tree for the most and 

least efficient scenarios, respectively. CO2 emissions 

can be reduced threefold by selecting energy-efficient 

equipment and vehicles, and twofold by operating them 

at maximum efficiency.

Model serves as tool to improve environmental responsibility through social media 

Web 2.0 and social media have considerable potential for 

facilitating connections to nature and spurring 

proenvironmental action. A station researcher developed 

the Technologies for Proenvironmental Action Model, a 

conceptual framework that explains how different 

functions of Web 2.0 and social media (i.e., informational, 

relational, and experiential) can generate or facilitate 

personal, social, and contextual pathways to 

environmentally responsible behaviors, especially among 

youth. For example, the relational function of social 

networking sites may be particularly effective in 

communicating social norms supportive of 

environmentally responsible behavior. Visitors to a site 

may report their own actions through stories and 

first-hand accounts, thereby 

encouraging others to take 

similar measures. Making use of 

this model and the underlying 

principles may enhance social 

media outreach and engagement 

efforts within the agency, helping 

to focus efforts to those 

approaches with greater 

anticipated effectiveness.

WEB 2.0 and 

Social Media Functions

Informal

Relational

Experimential

Pathways

Personal

Social

Contextual

Facilitate

 Generate

Proenvironmental Action

E.g., driving a hybrid vehicle, 

recycling, and 

regulating household energy use.

The Technologies for Proenvironmental Action Model 

(TPAM): a conceptual model linking the functions of 

Web 2.0 and social media in generating and/or 

facilitating pathways to proenvironmental action.

Will the amount of carbon stored over the next 50 years by street trees 

in Los Angeles exceed the amount emitted by tree care activities? 

(City Plants/Elizabeth Skrzat)

A young filmmaker shoots footage for a 

video about what the outdoors means to 

youth. (BAYCAT)
Research Partners

The PSW Research Station depends on its many partners and collaborators in developing and 

delivering cutting-edge, practical science to the public.

Conservation strategy developed for fishers in the Southern Sierra

In 2015, a multiyear collaboration between 

the Conservation Biology Institute, USDA 

Forest Service Region 5, and PSW 

Research Station resulted in the completion 

of a comprehensive Fisher Conservation 

Strategy for the southern Sierra Nevada 

region. Faced with threats from habitat loss, 

wildfire, poisoning from illegal marijuana 

cultivation, and predation, fishers are 

currently being considered for both state 

and federal endangered species listing. 

Using research data from multiple projects, 

the science team developed an innovative 

approach to map and evaluate habitat 

needed by adult female fishers to survive 

and reproduce in a changing landscape. 

The conservation strategy for the fisher 

represents a significant accomplishment for 

species conservation and a critical 

component in forest plan revision for 

the three southern national forests.

Partnership between the Carnegie Institution and the Institute of Pacific Islands Forestry celebrates a decade of research and development

The Hawaiian Islands host unique flora 

and fauna and encompass dramatic 

latitudinal and elevation gradients. 

Unfortunately, areas of Hawaii have 

already lost significant proportions of their 

native biodiversity, and remaining natural 

areas are threatened with continued loss 

without active, forward-thinking land 

management. Since 2005, station 

researchers have teamed up with the 

Carnegie Institute to measure Hawaii's 

ecosystems from the air. With support 

from the W.M. Keck Foundation, the team 

developed the Carnegie Airborne 

Observatory (CAO-1) in 2006 and the 

CAO-3 in 2015. Together, these systems 

represent the most scientifically advanced, 

aircraft-based mapping and data analytics 

system operating in the civil sector today. 

CAO-1 was deployed to Hawaii Island in 

2008 and revolutionized natural resources 

research, management, and 

decisionmaking. These flights allowed for 

first-ever landscape-scale mapping of 

invasive species 

presence, fuel 

conditions, 

aboveground carbon 

density, and 

structural forest 

properties. 

The station and the Brazilian Ministry of the Environment 

partner on fire and environmental change research

The Forest Service renewed its 

cooperation with the ministry of the 

environment of the Federative Republic of 

Brazil on the subject of fire and 

environmental change in tropical 

ecosystems with the signing of a 

Declaration of Intent by the Brazilian 

Minister of the Environment, Izabella 

Teixeira, and the chief of the Forest 

Service, Tom Tidwell. The cooperation is 

intended to build upon past work, current 

efforts, and new technologies to realize a 

rapid, integrated, and practical system for 

fire monitoring and prediction that will 

support fire management and policy, 

contributing to reduction of greenhouse 

gas emissions, improving air quality, and 

mitigating ecological, social, and 

economical fire damages.

Rapid feedback evaluations to inform meadow restoration

Mountain meadows serve important 

ecosystem service functions especially 

in times of drought or flood: they 

enhance groundwater recharge, 

dissipate energy from high flows, and 

store carbon in their oxygen-poor soils. 

These ecological functions are reduced 

when meadows and stream channels 

have been degraded as a result of land 

use or other disturbance events.

Restoring meadow functions has 

become a priority in drought-stricken 

California. However, the restoration of 

hydrologic function is complex and 

success can be elusive. Station 

scientists partnered with university 

researchers, land managers, and 

restoration practitioners to support 

restoration efforts by developing a 

monitoring approach that can provide 

rapid feedback to inform and enhance 

restoration implementation and success 

to improve hydrologic function, as well 

as other benefits such as carbon 

sequestration and biodiversity 

conservation.

Fishers in the southern Sierra Nevada face numerous threats to their existence. 

(National Park Service)

Active fire plume from burning in tropical forest and pasture near Maraba, 

Brazil, from which smoke was sampled and trace gases were measured. 

(U.S. Forest Service/Philip Riggan)

Carnegie Airborne 

Observatory mapping areas 

from 2007 to 2008 flights 

over major forested regions 

of Hawaii Island. These, and 

additional forest zones, will 

be remapped. 

(Carnegie Institution)

Geomorphologist Diane Montoya 

maps stream morphology at Big 

Flat on Cottonwood Creek. 

(U.S. Forest Service/Karen Pope)

Research Partners and Awards

Understanding the effects of the Get to Know Program on children’s connectedness with nature

The Get to Know Program is an international 

program aimed at fostering connections to 

nature. Working with several academic, 

government, and community organizations, 

the station performed the first systematic 

evaluation of three program components, 

providing valuable insights to the program 

partners and environmental educators at 

large. Findings demonstrate the value of the 

creative arts in environmental education for 

youth. Youth participants had marked 

increases in connections with nature after 

actively engaging in the creative arts 

contest. Findings also show that hiking a 

built adventure trail and taking a virtual hike 

were less effective at eliciting increased 

connections with nature. These results will 

help in development of effective tools for 

outreach focused on connecting 

participants with nature.

Station adds new cooperating experimental forest to portfolio of PSW research areas

The station signed an agreement with the 

Department of Natural Resources and 

Environmental Sciences at Cal Poly San 

Luis Obispo to recognize their Swanton 

Pacific Ranch as a new Cooperating 

Experimental Forest. The area, located 

near Santa Cruz, California, is a 3,200-

acre landscape composed of a majestic 

redwood forest, lush riverine ecosystems, 

and expansive coastal grassland 

overlooking the bay and the Pacific 

Ocean. Recognized for its biodiversity 

and abundant resources, the ranch 

provides a valuable opportunity to study 

the methods of resource conservation 

applied through sustainable management 

techniques. The U.S. Forest Service's 

system of experimental forests and 

ranges provides places specifically 

designated and administered to enable 

research that improves forest and range 

management. The 5-year agreement will 

facilitate an increase in research projects 

aimed at monitoring and predicting the 

effects of climate change on the nation’s 

farm, range, and forest lands.

Awards

Researcher wins prestigious 

ornithology award

The Cooper Ornithological Society 

recognized postdoctoral research 

wildlife biologist Jared Wolfe with 

the 2015 Young Professional 

Award for his outstanding 

scientific research and contributions to the ornithological profession. Wolfe’s work includes 

research on the effects of habitat 

and climate change on bird 

populations in forested landscapes. Results from this research 

suggest that many forest-dwelling 

birds are highly sensitive to 

fragmentation, exhibiting stark 

decreases in survival. 

Wildlife crossing work receives 

national recognition

The Federal Highway 

Administration awarded its 

2015 Environmental Excellence 

Award in Environmental 

Leadership to ARC (Animal 

Road Crossings) Solutions, 

a partnership seeking to make 

highway wildlife crossing 

structures a standard practice 

across North America through 

encouraging innovative costsaving designs. Forest Service 

awardees included PSW wildlife 

biologist Sandra Jacobson

and Tahoe National Forest 

public services officer Terry 

Brennan, both members of the 

ARC Solutions Steering 

Committee. ARC is an international network whose mission 

is to identify and promote 

leading-edge solutions to 

improve human safety, wildlife 

mobility, and long-term landscape connectivity.

“Tree Hero” honored for 

dedication to sustainable 

urban forests

The Sacramento Tree 

Foundation honored Research 

Forester Greg McPherson

with a Valley Oak Award for 

his dedication to creating 

sustainable urban forests 

across the Nation. The foundation, committed to growing the 

Sacramento region’s urban 

forest by leading an effort to 

plant 5 million trees, recognizes 

McPherson’s research, educational tools, and personal 

passion that inspire others to 

plant and protect trees. 

Scientists honored with Rise 

to the Future awards

Station scientists were among 

the recipients of the Rise to the 

Future awards for Fisheries, 

Hydrology, Soil Science and 

Air Programs. Research Plant 

Pathologist Mark Fenn received the Paul Miller Air 

Award in recognition of his 

international leadership in 

studying air pollution effects 

on the environment leading to 

advancement in air program 

management. The Kings River 

Experimental Watershed 

Group led by research ecologist Carolyn Hunsaker received 

the Jim Sedell Research 

Achievement Award for its role 

in developing and implementing a long-term ecosystem 

experiment on forest restoration effects in the headwaters 

of the Sierra Nevada. 

Station Director’s honor 

awards recognize 

outstanding achievements

Station Director Alex Friend 

presented PSW’s annual Station 

Director’s Honor Awards. The 

Honor Awards recognize 

employees who have made 

significant contributions to the 

mission of the Forest Service. 

Award recipients included Jim 

Baldwin for Distinguished 

Science; Christie Aldrete for 

Innovation and Service within the 

Station; Tom Cole for Safe and 

Healthy Workplace; and Craig 

Thompson for Science Delivery.

(Kristin Brzeski)

“Tree Hero” Greg McPherson (center) is pictured with 

former Sacramento Mayor Burnett Miller, Doris Matsui 

(U.S. Congress, California District 6), Cindy Blain (California 

ReLeaf), and Ray Tretheway (Sacramento Tree 

Foundation) at the awards ceremony. (Mary Gray)

Cal Poly San Luis Obispo’s Swanton Pacific Ranch joins the Forest Service’s network of experimental forests and ranges. (Cal Poly San Luis Obispo)

(L-R): 2015 Station Director’s Honor Award recipients 

Craig Thompson, Christie Aldrete and Jim Baldwin pose 

with PSW Station Director Alex Friend. Not pictured is 

recipient Tom Cole. (U.S. Forest Service/Sherri Eng)
STATION DIRECTOR

Dr. Alexander L. Friend 

(510) 883-8832

afriend@fs.fed.us

ASSISTANT DIRECTOR, RESEARCH

Dr. Jane L. Hayes

(510) 883-8835

jlhayes@fs.fed.us

ACTING ASSISTANT DIRECTOR, 

BUSINESS OPERATIONS

Kari Vasenden

(510) 883-8834

kvasenden@fs.fed.us

DIRECTOR, COMMUNICATIONS

Sherri Eng

(510) 883-8862

sleng@fs.fed.us

DIRECTOR, 

PARTNERSHIPS AND COLLABORATION

Dr. Rick Bottoms

(530) 759-1748

rmbottoms@fs.fed.us

DIRECTOR, RESEARCH PLANNING

A.J. Duggan

(510) 883-8836

aaduggan@fs.fed.us

PROGRAM MANAGER, 

CONSERVATION OF BIODIVERSITY

Dr. Patricia Manley

(530) 621-6882

pmanley@fs.fed.us

ACTING PROGRAM MANAGER, 

ECOSYSTEM FUNCTION AND HEALTH

Josh Wilson

(530) 286-2255

joshwilson@fs.fed.us

ACTING PROGRAM MANAGER, 

FIRE AND FUELS

Dr. Philip Riggan

(951) 680-1534

priggan@fs.fed.us

ACTING PROGRAM MANAGER, URBAN 

ECOSYSTEMS AND SOCIAL DYNAMICS

Dr. Patricia Winter

(951) 680-1557

pwinter@fs.fed.us

PSW-Albany (Headquarters)

800 Buchanan Street

Albany, CA 94710-0011 

Phone: (510) 883-8830

Fax: (510) 883-8858

PSW-Arcata

1700 Bayview Drive

Arcata, CA 95521-6013 

Phone: (707) 825-2900

Fax: (707) 825-2901 

PSW-Davis

1731 Research Park Drive

Davis, CA 95618 

Phone: (530) 759-1700 

Fax: (530) 747-0241 

PSW-Fresno

2081 E. Sierra Avenue

Fresno, CA 93710-4639 

Phone: (559) 323-3200

Fax: (559) 297-3355 

PSW-Hilo, Institute of Pacific Islands Forestry

60 Nowelo Street 

Hilo, HI 96720 

Phone: (808) 933-8121

Fax: (808) 933-8120

PSW-Placerville, Institute of Forest Genetics

2480 Carson Road

Placerville, CA 95667 

Phone: (530) 622-1225

Fax: (530) 622-2633 

PSW-Redding

3644 Avtech Parkway

Redding, CA 96002 

Phone: (530) 226-2530

Fax: (530) 226-5091 

PSW-Riverside

4955 Canyon Crest Drive

Riverside, CA 92507 

Phone: (951) 680-1500

Fax: (951) 680-1501

PSW Research Station Organization Locations

April 2016

Electronic version available at: www.fs.fed.us/psw/about/accomplishments/

USDA is an equal opportunity provider, employer, and lender.

DIRECTOR, INSTITUTE OF 

PACIFIC ISLANDS FORESTRY

Dr. Ricardo D. Lopez

(808) 854-2601

rdlopez@fs.fed.us

CREDITS

Director of Communications – Sherri Eng

Writers – A.J. Duggan, Sherri Eng

Graphic design – Jason Blake