Sources

andScience

United States 

Department of Agriculture

Forest 

Service

Pacific Southwest 

Research Station DEPAR TMENT OF AGRICULT URE A Guide to Experts at the 

Pacific Southwest Research Station
The U.S. Department of Agriculture (USDA) prohibits discrimination in 

all its programs and activities on the basis of race, color, national origin, 

age, disability, and where applicable, sex, marital status, familial status, 

parental status, religion, sexual orientation, genetic information, political 

beliefs, reprisal, or because all or part of an individual’s income is derived 

from any public assistance program. (Not all prohibited bases apply to all 

programs.) Persons with disabilities who require alternative means for 

communication of program information (Braille, large print, audiotape, 

etc.) should contact USDA’s TARGET Center at (202) 720-2600 (voice and 

TDD). To file a complaint of discrimination, write to USDA, Director, Office 

of Civil Rights, 1400 Independence Avenue, S.W., Washington, DC 20250-

9410, or call (800) 795-3272 (voice) or (202) 720-6382 (TDD). USDA is an 

equal opportunity provider and employer.
A Message From 

the Station Director

The Pacific Southwest (PSW) Research Station carries out the research and 

development mission of the USDA Forest 

Service in California, Hawaii, and the U.S.-

affiliated Pacific Islands. From the southern 

chaparral, montane Sierra Nevada, and coastal 

redwood ecosystems of California, across the 

ocean to the tropical wet and dry forests of 

Hawaii and the Pacific Islands, our scientists 

and professionals are dedicated to enhancing 

knowledge of complex natural resource issues 

and communicating this knowledge to society.

I invite you to browse this inaugural edition 

of our “experts guide” to meet our researchers, 

discover the diversity of the scientific work 

that we do, and see how our science is making 

a difference—today and tomorrow. 

Deanna J. Stouder

Station Director
Contents

Introduction

1 How to Use Sources and Science 

1 About PSW Research Station 

1 How to Contact Us 

Categories of Expertise

3 Economics and Social Research

7 Fire and Air

 

17 Forests and Plants

35 Wildlife and Aquatics

Glossary

47

Indexes

53 By Scientist

54 By Subject
1

How to Use Sources and Science

The Pacific Southwest (PSW) Research Station is a world leader 

in natural resources research through its scientific excellence and 

responsiveness to the needs of current and future generations. More than 

50 scientists currently conduct research for the station. More than half of 

them are profiled in this guide.

This guide is divided into four broad categories representing the featured 

researchers’ areas of expertise: economics and social research, fire and 

air, forests and plants, and wildlife and aquatics. A glossary and two 

indexes—by scientist and by subject—also are provided to help you 

understand and locate the information you need. 

About PSW Research Station

•	 Established in 1926

•	 One of seven research units of the U.S. Department of Agriculture,

Forest Service

•	 Headquarters in Albany, California

•	 Eight research facilities in nine locations across California, Hawaii,

and the U.S.-affiliated Pacific Islands

•	 Thirteen experimental forests

•	 About 250 employees

How to Contact Us

For help getting in touch with the right expert for your story, call 

PSW Research Station’s media desk at (510) 559-6327. You also can

learn more about us online at http://www.fs.fed.us/psw/. 

Economics and Social Research

3

5

Deborah Chavez

Research social scientist; Riverside, California

Deborah Chavez is working to make the Forest Service and its programs relevant to 

the Nation’s largest and fastest-growing 

constituent group—Latinos. Through her work, 

the research social scientist is helping to enhance 

the relationship Latinos and other ethnic groups 

have with the natural world.

Chavez conducts a variety of studies that explore 

the public’s use of natural resources and protected 

areas. She found, for example, that diverse youth 

overwhelmingly prefer nature-based activities that 

involve technology, like geocaching, to those that 

do not. She also conducted an adaptive outdoor 

recreation management study that identified key 

characteristics of outdoor recreation sites that 

served Latino groups in the Los Angeles area. 

Ultimately, these characteristics—like suitably 

sized picnic areas—were enhanced on the San 

Bernardino National Forest’s Applewhite Picnic 

Area. 

In the future, Chavez will develop syntheses of 

studies conducted over the past 20 years.

Economics and Social Research

Ask Her About

Nature-based 

recreation, race and 

ethnicity studies, law 

enforcement, trails, 

day-use recreation

Background

Ph.D., sociology, 

University of 

California, Riverside; 

member, International 

Association for Society 

and Natural Resources, 

National Association 

of Recreation Resource 

Planners
6

Patricia Winter

Research social scientist; Riverside, California

Patricia Winter is pursuing a line of inquiry that is at the core of the USDA Forest 

Service’s mission of caring for the land and 

serving people. As a research social scientist, 

her work is aimed at helping the agency and 

other natural resource organizations to better 

understand and, by extension, better serve diverse 

urban and near-urban populations. 

To conduct her research, Winter draws on a 

variety of quantitative and qualitative approaches 

from the social sciences, including surveys, 

interviews, observations, and archival analyses. 

Her work has shown, for example, that trust 

plays a pivotal role in agency-public interactions. 

These findings have led to the development of 

approaches for interacting and communicating 

with the public. More recently, her work has 

demonstrated the value of using community 

networks and ethnic media to reach diverse 

urban publics. 

Economics and Social Research

Ask Her About

Recreation 

management, 

communicating 

with diverse urban 

populations, role 

of social trust in 

land management, 

increasing 

environmentally 

responsible behavior

Background

Ph.D., psychology, 

The Claremont 

Graduate School; 

member, American 

Psychological 

Association, Society 

for the Psychological 

Study of Social 

Issues, Society for 

Risk Analysis
Fire and Air

7

9

Jan Beyers

Plant ecologist; Riverside, California

After a fire burns through a landscape, one common management response is to 

conduct postfire watershed rehabilitation, which, 

ultimately, costs millions of dollars annually. Jan 

Beyers works to ensure that the efficacy of these 

treatments and their potential ecosystem effects 

are known. 

Beyers is a plant ecologist who focuses much 

of her research on the effectiveness of postfire 

rehabilitation treatments. In one study, she 

examined postfire ryegrass seeding in burned 

areas of chaparral in southern California and 

found that the practice had little effect on 

postfire erosion. The planting of ryegrass, in fact, 

interfered with the growth of native postfire flora. 

As a result of this study and others, little seeding 

is now done on burned areas of chaparral in the 

region, and use of ryegrass for postfire seeding 

has decreased throughout the state. 

In collaboration with two colleagues, Beyers also 

published a review of the effectiveness of a wide 

range of postfire rehabilitation treatments. The 

report ultimately led to national-level funding 

and has stimulated a great deal of research on 

treatment effectiveness that is helping managers 

to decide if, or with what, to treat burned lands.

In the future, Beyers will continue studying 

the effectiveness of new postfire treatments, 

particularly those that are extremely expensive 

or controversial with the public, as well as the 

impacts of treatments on native vegetation 

recovery and effects on invasive plants. 

Fire and Air

Ask Her About

Postfire rehabilitation 

treatments, chaparral 

response to fire, fuel 

treatment effects on 

invasive species, fire 

response of rare species

Background

Ph.D., botany, Duke 

University; member, 

Association for Fire 

Ecology, Ecological

Society of America, 

International 

Association of 

Wildland Fire, 

Society for 

Conservation 

Biology
10

Andrzej Bytnerowicz

Ecologist; Riverside, California

Andrzej Bytnerowicz is an expert on air pollution and the chemical environment of 

forests, integral aspects of the changing climate. 

Bytnerowicz, an ecologist, is a pioneer of 

methods for characterizing the distribution of 

air pollution at large geographic scales, such as 

landscapes or regions. He draws on a network of 

passive samplers that detects concentrations of air 

pollutants in mountains and other remote areas 

and uses geostatistical software to create pollution 

distribution maps. He has developed a passive 

sampler for nitric acid vapor, the air pollutant 

responsible for a large portion of nitrogen 

deposition in western forests and ecosystems. 

Bytnerowicz is motivated by his ability to 

contribute to the fundamental understanding of 

forests’ chemical environments—an area that, he 

says, is largely unexplored yet extremely critical to 

understanding present and future forest changes. 

Ask Him About

Air pollution, climate 

change, effects of 

wildland fires on 

air quality

Background

Ph.D., natural sciences, 

Silesian University 

(Katowice, Poland)

Fire and Air
11

Fire and Air

Shyh-Chin Chen

Research meteorologist; Riverside, California

I

n a region like southern California, ShyhChin Chen’s research is right at home. His 

work focuses on fire danger prediction—an 

invaluable service given the threat seasonal 

wildfires pose to lives, properties, and landscapes 

in the highly populated and fire-prone region.

As part of his research, Chen, a research 

meteorologist, develops fire danger forecasts 

using meteorological climate models. Such 

applications are critical to fire danger 

management. Chen also simulates largescale weather patterns, which help to explain 

variations in regional climate. 

In the future, Chen will continue to focus 

his research on fire danger and behavior 

predictions, motivated, as he is, by work that 

contributes to the protection of communities. 

Ask Him About

Climate dynamics, 

regional climate, 

weather and climate 

forecasts, fire danger 

Background

Ph.D., atmospheric 

sciences, University 

of Illinois
12

Francis Fujioka 

Research meteorologist; Riverside, California

Francis Fujioka is a research meteorologist whose work helps fire management agencies 

to protect firefighters and inhabitants of the 

wildland-urban interface. 

Fujioka began work in this area in the 1980s,

when he supervised the development of the 

Forest Service’s monthly fire weather forecasting 

system and the use of numerical weather models 

for long-range fire weather forecasting. More 

recently, he has developed a method to analyze 

the uncertainty in fire spread predictions. 

Collectively, these projects contribute to a 

common goal of developing predictive tools 

for fire management that incorporate uncertainty 

for quantitative risk assessment. 

In the future, Fujioka plans to extend 

applications of modeling and remote sensing 

to fire management operations. 

Ask Him About

Fire meteorology, fire 

climatology, weather 

and fire modeling

Background

Ph.D., earth sciences, 

University of 

California, Riverside; 

member, American 

Meteorological Society, 

Sigma Xi Scientific 

Research Society

Fire and Air
13

Eric Knapp

Research ecologist; Redding, California

For Eric Knapp, frequent forays into the woods—to hike, backpack, and photograph—are ideal 

sources of research inspiration that provide valuable 

insights into the natural landscapes he studies. 

Knapp is a research ecologist whose work examines 

both prescribed and wild fire and, particularly, 

their effect on plants and animals and interaction 

with silviculture and other practices. Historically, 

most wildfires in the West occurred during the 

late summer or early fall. Many prescribed fires, 

however, are ignited in the spring or early summer, 

at a time when plant growth and animal activity are 

at their height, raising the concern that the burns 

could have damaging ecological effects. Knapp’s 

research has helped to determine the effects that 

seasonal timing can have on an ecosystem and 

suggests that fuels can be effectively managed 

with burning in any season.

Knapp also is interested in studying how fire 

suppression has changed forest structure. His 

colleagues have remapped historical research plots 

established 80 years ago, showing that tree density

has more than doubled and stands have become 

much less variable than they were prior to logging 

and fire suppression. He is using the historical stand 

information to develop ideas for thinning forests in 

ways that restore some of the past complexity, while 

also making them more resilient to wildfire. 

In the future, Knapp will apply the knowledge he 

has acquired from smaller, plot-based studies to the 

landscape to address broader forest management 

issues. In this way, he will continue to generate 

findings that guide the return of fire to fire-adapted 

forests of the Western United States. 

Ask Him About

Fire ecology, fire 

effects on plants 

and animals, fuel 

management 

strategies, firesilviculture 

interactions, 

landscape-scale 

wildfire severity 

patterns, effects of 

disturbance, forest 

change over time 

Background

Ph.D., genetics, 

University of 

California, Davis

Fire and Air
14

Constance Millar

Research climate ecologist; Albany, California

Constance Millar has found that spending as much time as possible in the mountains with 

her eyes open and her head theory-free is one of 

the best formulas for her research. It is in these 

field experiences that she generates questions 

and makes observations that guide her evolving 

studies. 

Millar is a research climate ecologist whose 

work explores the response of forests and their 

inhabitants to climate change—both past and 

present. Her work has demonstrated, for example, 

that historical changes in forest composition, 

structure, and distribution in response to 

climate variability have been far more drastic 

than is often recognized. These insights provide 

clues to potential changes in future forests 

under global warming and offer a context for 

management response. As part of this research, 

Millar has documented complete extirpation 

and recolonizations by limber pine over the last 

4,000 years in the Great Basin mountains. These 

major shifts correspond to century-long droughts 

that recurred periodically over the last millennia. 

Changes in forests at such a large scale have not 

been incorporated into management thinking 

and, thus, provide a larger window into potential 

future responses in the face of global warming. 

In the future, Millar plans to continue studies 

aimed at better understanding historical and 

future responses of mountain ecosystems to 

climate variability. 

Ask Her About

Response of subalpine 

forests to historical 

and current climate 

change, rock glaciers, 

American pikas, forest 

management amidst 

climate change, Sierra 

Nevada and Great 

Basin mountains

Background

Ph.D., genetics, 

University of 

California, Berkeley; 

co-director, 

Consortium for 

Integrated Climate 

Research in 

Western Mountains 

(CIRMOUNT); cochair, North American 

Global Observation

Research Initiative in 

Alpine Environments

(GLORIA) Chapter

Fire and Air
15

Jim Simpson 

Meteorologist; Davis, California

J

im Simpson’s work provides a fiscal basis for 

planting, maintaining, and improving urban 

 forests, or, as he refers to them, “the forests 

where we live.” 

In one pioneering study, Simpson, a 

meteorologist, worked with the Sacramento 

Municipal Utility District to evaluate the effect of 

the shade of 200,000 trees planted by the utility

on residential space. Working from a very large 

number of properties and factoring in details on 

actual tree size and placement, building vintage, 

and window location, Simpson helped to develop 

benefits-based criteria for locating suitable tree 

planting sites that were used to evaluate the costeffectiveness of the utility’s shade tree program. 

Simpson also provided detailed environmental 

analyses that formed the basis of tree guides 

and the Municipal Forest Resource Analysis. 

His work helped to identify and describe the 

benefits and costs of planting trees in a specific 

climate region, providing useful information to 

community officials and tree managers. 

In the future, Simpson plans to develop better, 

easier-to-use tools that make the results of his 

research more accessible to diverse audiences.

Ask Him About

Urban forests’ effects 

on building energy 

use, air quality, 

climate change

Background

Ph.D., forest 

meteorology, 

University of 

Washington

Fire and Air
16

David Weise

Supervisory research forester; 

Riverside, California

Wildfire is a formidable natural resource issue in California—one need only look 

as far as the state’s devastating 2008 and 2009

fire seasons for proof. Models, such as those that 

predict fire spread, are essential to controlling 

wildfires and to managing prescribed burns. 

David Weise is conducting research aimed at 

updating these models—which were developed 

in the 1960s using dead fuels as their basis—so

that they will better predict fire spread among 

live shrub fuels, like chaparral, which dominate 

much of California. 

In one study, Weise, a supervisory research 

forester, explored the effects of wind speed and 

slope, two variables that can greatly affect fire 

behavior. Using a specially designed tilting 

wind tunnel, he was the first to examine the 

combined effects of the two variables on a fire’s 

rate of spread and flame length. Ultimately, he 

found that the existing model used to predict rate 

of spread could not accurately account for the 

combined effects of wind and slope. His findings 

led to new estimates for flame length. 

In other work, he and a colleague conducted the 

first studies to evaluate how a cone calorimeter—a 

special fire safety tool—can be used to measure 

plant flammability. Findings from this study 

will inform the “low fire hazard” ratings 

often assigned to landscape plants and help 

homeowners and others to reduce fire hazards 

on their property. 

In the future, Weise will continue his 

examination of the various factors that influence 

fire spread in live shrub fuels, ultimately helping 

to improve the ability to predict fire behavior. 

Ask Him About

Fire behavior, 

modeling fires, fuel 

moisture, landscapescale vegetation 

models, use of 

prescribed fire

Background

Ph.D., wildland 

resource science, 

University of 

California, Berkeley; 

member, Society of 

American Foresters

Fire and Air
Forests and Plants

17

19

Susan Cordell

Research ecologist; Hilo, Hawaii

Susan Cordell has a deep-rooted passion for the unique ecosystems of Hawaii and the Pacific 

Islands. As a research ecologist, her work is aimed 

at preserving and restoring the native ecosystems 

of this region, many of which are threatened or 

endangered. 

Much of Cordell’s research focuses on ecosystem 

processes within tropical forests and the impacts 

of nonnative plant species on essential processes, 

like nutrient and water cycling. In Hawaii and 

the Pacific Islands, where high levels of endemic 

species are found, the introduction and spread of 

invasive species is particularly troubling for the 

relatively fragile ecology of the islands. Native 

species are poorly adapted to outcompete invasive 

species for resources and, often, the invasive 

species have no natural predators to keep them in 

check. Cordell also is exploring the factors that 

impact Pacific Island forests’ ability to recover 

from disturbances and is generating findings that 

are providing the basis for ecosystem restoration 

and management activities. 

Cordell says the most rewarding part of her 

research is inspiring others to conserve Hawaiian 

and Pacific Island ecosystems. In the future, 

she intends to continue developing research 

and collaborating with local communities to 

advance effective conservation, preservation, and 

restoration-related land management efforts. 

Ask Her About

Hawaiian and Pacific 

Island ecosystems, 

ecophysiology, 

functional ecology, 

tropical dry forests, 

restoring ecosystem 

processes 

Background

Ph.D., botanyecophysiology, 

University of Hawaii 

at Manoa; member, 

Ecological Society of

America, Botanical 

Society of America, 

Society for Ecological

Restoration 

Forests and Plants
20

Susan Frankel

Biologist; Albany, California

When Susan Frankel joined the station in 2005, it was to address a forest health

emergency. Five years earlier, sudden oak death 

(SOD), an exotic and invasive pathogen, was

first discovered in the Bay Area. It ultimately 

was to devastate millions of oaks and tanoaks 

in coastal California and southern Oregon,

destroying not only these symbols of great natural 

beauty and the valuable acorns they provide, 

but changing fire behavior patterns. A forest 

pathologist by training, Frankel developed and 

assumed leadership of the then newly established 

Sudden Oak Death Research Program, charged

with developing treatments and strategies for 

slowing the spread of, managing, and, ultimately, 

eradicating the disease. 

In the span of only a few short years, Frankel’s 

program has developed field and laboratory 

diagnostic methods, management strategies, 

and basic biological understanding of the SOD

pathogen’s spread—all of which have been 

essential to the design of regulations in forests, 

nurseries, and residential landscapes. And 

because the SOD pathogen was new to

science at the time, her program is a model 

for emergency research to respond to newly 

found invasive species.

In the future, Frankel plans to broaden her focus 

to include considerations of the role of climate 

change in forest pathogens, the economic and 

social impacts of tree diseases, patterns of tree 

mortality, and biosecurity and quarantine policy. 

Ask Her About

Sudden oak death, 

forest pathology, 

invasive species, 

forest diseases and 

climate change

Background

M.S. and M.F.R., 

forest pathology and 

silviculture, University 

of Washington; 

member, American 

Phytopathological 

Society, California Oak

Mortality Task Force, 

California Pest Council 

Forests and Plants
21

Christian Giardina 

Research ecologist; Hilo, Hawaii

The carbon cycle is central to discussions about climate change, with forests 

acknowledged as being potential sources or 

sinks of atmospheric carbon dioxide. Christian 

Giardina studies climate change and carbon cycle 

science, generating results that are informing 

managers’ decisions about individual species and 

management strategies. 

In one study, Giardina, a research ecologist, found 

that soil carbon decomposition is insensitive 

to temperature, a finding with significant 

implications for forest carbon storage in the face 

of climate change. He also found that tree species 

have variable and sometimes unpredictable effects 

on soil carbon quality and persistence. 

The results of Giardina’s work show that 

forests may continue to serve as global sinks of 

atmospheric carbon dioxide for years to come. 

In the future, he plans to study how climate 

change issues can be incorporated into large-scale 

restoration efforts.

Ask Him About

Climate change, 

global change, 

carbon cycle science, 

ecosystem ecology, 

restoration 

Background

Ph.D., biology, 

University of Denver

Forests and Plants
22

Andrew Groover 

Geneticist; Davis, California 

Wood—the indisputable basis of the Nation’s 

forest industry—is central to many of the topics 

that dominate today’s headlines, from carbon 

sequestration to greenhouse gas emissions. 

Andrew Groover is studying how the formation 

of this most vital resource is regulated at the most 

basic level—the genetic level. 

Groover is a geneticist and Director of the 

station’s Institute of Forest Genetics, a laboratory 

that develops technologies for discovering 

and characterizing forest tree genes and that 

studies the role of those genes in regulating key 

biological processes. He and his colleagues have 

identified and characterized genes that directly 

influence basic wood properties, which can help 

with discussions of forest products, bioenergy, 

and carbon sequestration. Their findings also 

ultimately speak to the ecological relevance of 

wood in forest ecosystems. Groover also has 

participated in the interpretation of the Populus

genome, the first fully sequenced genome for a 

forest tree. 

In the future, Groover, who describes his research 

approach as genetic detective work, will expand 

the focus of his studies beyond individual genes to 

understand genetic relationships involved in forest 

tree development. 

Ask Him About

Wood development, 

genomics and genetics 

of trees, carbon 

sequestration

Background

Ph.D., biology, 

University of North 

Carolina-Chapel Hill; 

member, American 

Society of Plant 

Biology, International 

Association of Wood 

Anatomists

Forests and Plants
23

Valerie Hipkins

Geneticist; Placerville, California

As the foundation of life, it’s not surprising that genes also contribute greatly to 

successful forest management. Our ability

to establish and sustain healthy forests and 

rangelands—especially in the face of current 

pressures such as climate change—rests on our 

understanding of genetics, which help us to assess 

past, current, and future biological changes. 

Valerie Hipkins’ career is devoted to understanding genetic issues in forestry. As a geneticist 

and Director of the station’s National Forest 

Genetics Laboratory (NFGEL), she works

with resource managers throughout the United 

States to provide the genetic information they 

need to aid their management decisionmaking. 

She and her colleagues use state-of-the-art 

technology to address genetic conservation and 

management of plant species using numerous 

laboratory techniques, including DNA analyses. 

To help planning efforts on forest lands across the 

country, Hipkins and her colleagues generated 

genetic information on over 140 different plant

species, including conifers, hardwoods, grasses, 

shrubs, and forbs.

In the future, Hipkins will continue to link 

science to management with a genetics emphasis 

to meet resource management needs. To her, 

forest genetics and the work being conducted 

at NFGEL are some of the best examples of

objective-driven science, where outcomes are 

directed by managers, the people who ultimately 

use the findings. 

Ask Her About

Plant genetics, 

genetic conservation, 

molecular genetics 

Background

Ph.D., genetics and 

forestry, Oregon

State University

Forests and Plants
24

Richard Flint Hughes

Research ecologist; Hilo, Hawaii

Motivated by a desire to help protect the world’s forests and the biodiversity 

contained within them, Richard Flint Hughes is 

a research ecologist who specializes in the native 

ecosystems of Hawaii and the Pacific Islands. 

Hughes’ work helps people to better understand 

the state of—and threats to—their forest 

resources. 

One area of Hughes’ research examines the

impacts of invasive species on native forests. 

In a series of studies, he has documented the 

effects of the invasive and fast-growing albizia 

tree on Hawaii’s wet lowland forests. He found 

that the presence of the invasive tree changed 

leaf litter quantity and quality, which changed 

decomposition rates and increased the amount of 

two key soil nutrients, nitrogen and phosphorus. 

The changes were a result not only of albizia 

invasion, but the subsequent invasion by other 

plants that the invasive tree facilitated. Resource 

managers from the State’s Division of Forestry 

and Wildlife and National Park Systems of 

Hawaii and American Samoa have used these 

research results to control albizia populations 

across landscapes within their respective 

jurisdictions. 

In other research, Hughes and his colleagues 

helped to develop an integrated satellite, airborne, 

and field-based mapping approach to accurately 

inventory forest carbon pools at multiple scales. 

This technique has been advanced by the United 

Nations Program for Reducing Emissions from

Deforestation and Forest Degradation as an 

effective means to improve monitoring of carbon 

stocks around the world.

Ask Him About

Native Hawaiian 

ecosystems, biomass 

mapping, impacts 

of invasive species 

in Hawaii and the 

Pacific Islands, 

nutrient storage 

and cycling 

Background

Ph.D., forest 

science, Oregon

State University; 

member, Ecological

Society of 

America; State of 

Hawaii’s Natural 

Area Reserve 

Commission

Forests and Plants
25

Sylvia Mori

Mathematical statistician; Albany, California

Sylvia Mori takes great pride in helping to ensure that scientific findings are sound 

and defensible. As a mathematical statistician, 

she partners with station scientists, university 

cooperators, and international colleagues to 

improve data sampling and analytical methods.

Mori thrives on the challenge of helping scientists 

to develop sound statistical methods to analyze 

complex data sets and present the results in such 

a way that they withstand scientific scrutiny. Her 

work allows her to combine her dual passions for 

biology and mathematics in a way that advances 

science.

Ask Her About

Experiment

and sampling 

design, large-scale 

monitoring, statistical 

modeling, statistical 

computing

Background

M.A., statistics, 

University of 

California, Berkeley; 

M.A.; mathematics; 

Universidad Técnica 

del Estado; Santiago,

Chile

Forests and Plants
26

Malcolm North

Research forest ecologist; Davis, California

Malcolm North is a research forester who specializes in the study of disturbance 

effects on forests and ecosystem restoration. 

His work is driven by the realization that fuels 

need to be reduced in many western forests, yet 

the ecosystem effects of doing so are not well 

understood. 

One major emphasis of North’s work is managing

forest carbon in wildfire-prone ecosystems. 

Because forests can be both major sources or sinks 

for carbon that contribute to global warming, he 

is examining how to best reduce carbon emissions 

and stabilize carbon stocks with fuel treatments.

North also is studying the ecological effects of 

fuel treatments. His work is helping managers and 

researchers to better understand how prescribed 

fire and mechanical thinning, which are used 

to reduce accumulated fuels, affect ecological 

processes and forest health.

In the future, North plans to explore carbon 

stocks and how carbon emissions may be reduced 

as the global climate changes.

Ask Him About

Fire and fuels, forest 

restoration, climate 

change, forest carbon, 

forest management, 

ecosystem health 

Background

Ph.D., forest ecology, 

University of 

Washington 

Forests and Plants
27

Pamela Padgett

Plant biologist; Riverside, California

Pamela Padgett’s career was inspired by simple questions—like, for example, why does a rose 

look and grow differently than an apple? Ultimately, 

her informal inquiries led to a hearty appreciation 

for plants and the realization that they enabled the 

establishment of human cultures. Now, as a plant 

biologist, she studies how human cultures affect 

plants—through air pollution, disturbance, and the 

introduction of new species. 

In one study, Padgett explored the impact of the 

air pollutant nitric acid on plants. Traditionally, 

nitrogen deposition has been regarded as an overfertilization problem likely to promote increased 

plant growth. But, in laboratory experiments, she 

found that dry deposited nitric acid is absorbed 

directly through leaf surfaces, which enables 

the pollutant to bypass the normal regulatory 

mechanisms found in roots. Repeated deposits of 

nitric acid actually result in a chemical attack on a 

plant’s protective wax layer, leaving them vulnerable 

to subsequent environmental and biological stressors. 

In another study, she demonstrated that by 

changing nitrogen availability, one changes the 

plant community structure. Many plants in western 

ecosystems are adapted to relatively infertile 

environments—that is, those devoid of nitrogen and 

other nutrients that stimulate growth. Thus, when 

nitrogen is increased, it reduces the competitive 

advantage of these species, rendering them 

vulnerable to being overrun by less adapted plants, 

often invasive species. 

In the future, Padgett plans to increase her 

interagency collaborations, ultimately guiding the 

management of public lands and encouraging the 

public to value their natural surroundings. 

Ask Her About

Mineral nutrition of 

plants, effects of soil 

on plant communities, 

nitrogen deposition 

in atmosphere and 

soils, mechanisms for 

invasion and control 

of invasive plant 

species

Background

Ph.D.; botany and 

plant sciences; 

University of 

California, Riverside; 

member, National 

Atmospheric 

Deposition Program

Forests and Plants
28

Paula Peper 

Ecologist; Davis, California

Paula Peper is an ecologist at the Center for Urban Forest Research, where she and her 

colleagues work to improve the habitat in which 

people live—towns and cities—and to provide 

useful tools for urban forest managers, planners, 

and landscape architects. 

Motivated by a desire to reduce the negative 

impacts that people have on the environment, 

Peper developed equations for tree height, crown 

diameter, leaf area, and diameter at breast height 

for 280 urban tree species. These equations form

the basis of the iTree STRATUM software 

application, which estimates the environmental 

and aesthetic benefits of trees as well as costs of 

tree management. These equations also allow 

users of the national version of the Tree Carbon 

Calculator to estimate annual carbon storage to 

meet requirements for urban forest carbon project 

reporting protocols.

Peper also developed a nondestructive method 

for estimating leaf area of open-grown trees 

using digital photography. Her technique allows 

researchers and iTree STRATUM users to 

estimate urban trees’ rainfall and stormwater 

interception, air quality benefits, and biomass. 

In the future, Peper plans to work on refining tree 

growth models using statistical methods.

Ask Her About

Urban trees, urban 

tree measurement 

and growth, 

biomass, urban 

tree site assessment

Background

B.A., English,

California State 

University, 

Sacramento; 

renewable natural 

resources, University 

of Nevada, Reno; 

member, California 

Urban Forest 

Council, Ecological

Society of America

Forests and Plants
29

Haiganoush Preisler

Mathematical statistician; Albany, California

For as long as she can remember, Haiganoush Preisler has loved working on puzzles. As a 

mathematical statistician, she works on puzzles 

every day and describes her work as the process of 

finding patterns in what appears to be chaos.

In collaboration with other scientists, Preisler has 

worked on a variety of projects, from the analysis 

of insect bioassay data to the modeling of animal 

movements with telemetry equipment. Recently, 

she has developed probabilistic risk models 

for evaluating and predicting impacts of forest 

threats—such as insect outbreaks, major wildfires 

and changing climate—on forest health.

Preisler’s work is usually prompted by the need 

for statistical methodologies suitable for new data 

types as they are developed by other research 

scientists in the environmental sciences.

Ask Her About

Analyzing spatial 

and temporal data, 

probabilistic risk 

assessment of forest 

threats, statistical 

methodology

Background

Ph.D., statistics, 

University of 

California, Berkeley

Forests and Plants
30

Martin Ritchie 

Biometrician; Redding, California

Martin Ritchie is a biometrician who develops mathematical models to 

describe the dynamics of forest stands, 

particularly those that help land managers 

to better manage coniferous forests. 

Ritchie has participated in several modeling 

efforts, including ORGANON and SYSTUM-1.

He was the primary developer of the CONIFERS

growth and yield model, a computer-based 

simulator that allows foresters to predict the 

growth of young plantations in response to various 

management practices. He also has studied the 

effect of thinning on the accumulation of biomass 

in ponderosa pine forests in northern California. 

This work gives managers tools for quantifying 

biomass responses after thinning treatments, an 

important consideration when managing forest 

fuels to reduce fire severity. 

Currently, Ritchie is studying large-scale 

spatial patterns in ponderosa pine forests, the 

development of mixed-conifer stands after 

wildfire, and the use of LIDAR imagery to 

inform management decisionmaking. 

Ask Him About

Forest modeling, 

silviculture and 

management of 

interior pine or 

mixed-conifer forests, 

growth and yield, 

biometrics 

Background

Ph.D., forest 

biometrics, Oregon

State University; 

member, Society of 

American Foresters, 

American Statistical 

Association 

Forests and Plants
31

Paul Scowcroft

Research forester; Hilo, Hawaii

I

n Paul Scowcroft’s own words, he is in the 

business of finding ways to help damaged 

forests heal. Scowcroft is a research forester 

whose work is aimed at successfully restoring 

and managing mid- and upper-elevation native 

Hawaiian forests.

Much of Scowcroft’s work is centered on koa, 

a fast-growing overstory tree that is native 

to Hawaii and a key species in reforestation 

plans in the islands. His work contributed to 

development of the first koa stocking guidelines, 

which help to guide how the species should be 

grown and managed. Private landholders in 

Hawaii, including The Nature Conservancy and 

Kamehameha Schools, have begun using the 

guidelines to design koa thinning operations. 

Recently, he and his colleagues produced a report 

that summarizes the ecology and silviculture of 

koa. 

Scowcroft’s work also identifies obstacles that 

impede restoration of native Hawaiian species 

on degraded landscapes and evaluates strategies 

to improve success. His research demonstrates 

that intact, self-sustaining native forests provide 

ecosystem services that alien-dominated or 

degraded landscapes cannot.

In the future, Scowcroft plans to continue 

developing and refining silvicultural guidelines 

for managing koa forests for wood as well as a 

host of other important ecosystem services.

Ask Him About

Native Hawaiian 

forests and terrestrial 

ecosystems, koa, 

human-assisted forest 

restoration, ecological 

impact of wild 

ungulates

Background

M.S., wildland fire 

ecology, University of 

Missouri; member, 

Soil Science Society 

of America 

Forests and Plants
32

Carl Skinner

Geographer; Redding, California

Before Carl Skinner became a scientist, he spent 20 years in fire services working in both fire

suppression and prescribed fire application. He 

credits this experience for providing him with a 

background in fire behavior that has proven to be 

a tremendous asset in interpreting fire history and 

severity patterns. 

Skinner is a geographer whose studies are among 

the first to describe fire’s long-term influence 

on wildlife habitat distribution and riparian 

environments. In a series of studies, he described 

the climate-fire-vegetation interactions in the 

complex landscapes of northern California and 

found, contrary to conventional wisdom, that 

within a particular climate zone, topography 

appears to have controlled fire parameters more 

than did vegetation type. Managers can use his 

work to help plan landscape-scale management 

strategies for a variety of activities, including fire 

hazard reduction. 

The 2002 Cone Fire burned 2,000 acres in

the Blacks Mountain Experimental Forest,

serendipitously giving Skinner and his colleagues 

the opportunity to assess the effectiveness of 

several previous silvicultural treatments in 

influencing the fire’s behavior. Since the burn, 

Skinner has been planning and conducting postfire 

effects research that includes studies of postfire 

salvage logging on fuels and understory succession.

In the future, Skinner plans to continue 

researching the influences of climatic variation 

on fire regimes and their combined influences 

on forest vegetation dynamics. 

Ask Him About

Fire ecology, fire 

history, fire-climate 

interactions, forest 

fuel management, 

climate change

Background

M.A., geography; 

California State 

University, Chico; 

member, Association 

for Fire Ecology,

International 

Association of 

Landscape Ecologists,

Tree-Ring Society

Forests and Plants
33

Forests and Plants

Jianwei Zhang

Research forester; Redding, California 

Having grown up in northwest China in a remote village with no running water 

or electricity, Jianwei Zhang is accustomed 

to experiencing firsthand the complexity and 

harmony of natural ecosystems. In fact, he 

credits his youth with fostering in him a desire 

to understand these systems and to manage 

them sustainably.

Zhang is a research forester whose research 

examines the effect of forest management on longterm stand dynamics. In one study, he analyzed 

long-term data gathered from plots of ponderosa 

pine, white fir, and red fir and found that thinning 

stands of these trees not only enhanced economic 

value—by increasing the growth of the remaining 

trees—but also significantly reduced fuel buildup. 

These quantitative findings can help managers 

with their stand treatment projects. 

In past research projects, Zhang pioneered the 

use of a stable carbon isotope to study population 

variation in the water-use efficiency of forest trees, 

which provided a new, extensively cited tool to 

study the physiological response of trees to their 

environment.

In the future, Zhang will continue his silvicultural 

research using physiological ecology techniques 

with the overarching goal of developing stateof-the-art tools for use in multiple-resource 

management. 

Ask Him About

Silviculture, 

tree physiology 

ecology, vegetation 

competition, stand 

growth models, 

managing forests for 

carbon 

Background

Ph.D., forestry, 

University of Idaho; 

member, Society of 

American Foresters, 

Ecological Society

of America 

Forests and Plants

Wildlife and Aquatics

35

37

Christopher Fettig

Research entomologist; Davis, California

As far as many coniferous forests are concerned, no agent wreaks more havoc than 

the bark beetle. By tunneling through the trees’ 

bark to lay their eggs, the insects have, in the 

last decade, caused unprecedented levels of tree 

mortality throughout much of the Western United 

States. Bark beetle outbreaks have a broad range of 

impacts, from reduced timber production and real 

estate values to decreased biodiversity and carbon 

storage. 

Christopher Fettig is a research entomologist 

who is developing methods for managing and 

monitoring bark beetles. Recently, for example, 

he demonstrated that special types of chemicals, 

known as semiochemicals—which contain 

pheromones that discourage beetle aggregation 

and that mimic the odor of nonhost trees—can 

be successful in protecting ponderosa pine from 

western pine beetle attack. Fettig has repeated 

these results in several additional studies, paving 

the way for registration of the chemical as a new 

biopesticide for protecting individual trees from 

bark beetle attack.

Fettig also is studying the role fuel treatments 

and prescribed fires have on subsequent levels 

of bark-beetle-caused tree mortality. To date, 

his research demonstrates that some bark beetle 

activity is exacerbated by these types of treatments 

in the short term. In response to his findings, he 

developed guidelines that assist resource managers 

charged with reducing fire risk, especially in the 

wildland-urban interface. 

In the future, Fettig plans to continue developing 

knowledge and tools that allow managers to better 

care for forest resources. 

Ask Him About

Impact of prescribed 

fire and mechanical 

fuel treatments 

on forest health, 

monitoring and 

managing bark 

beetles, economic 

importance of bark 

beetles

Background 

Ph.D., forest 

entomology, 

University of 

Georgia; member, 

Association for Fire 

Ecology, California

Forest Pest Council, 

Entomological

Society of America

Wildlife and Aquatics
38

Nancy Gillette 

Research entomologist; Albany, California 

Bark beetles pack a one-two punch and can be devastating forest pests—they can kill conifers 

by boring through their bark to lay their eggs 

and can also introduce pathogens directly into a 

tree’s vulnerable core. Nancy Gillette is a research 

entomologist whose work is generating enhanced 

methods for minimizing bark beetle damage to 

coniferous forests. 

Much of Gillette’s work is aimed at exploring the 

use of pheromones to deter beetles from attacking 

trees. These special olfactory chemicals can be 

applied directly to trees or their surroundings 

and act as a repellant, often by mimicking the 

odor of nonhost trees. In her studies, Gillette 

has developed pheromone-releasing flakes that 

can be applied from the ground or from aircraft, 

providing significant and landscape-scale 

protection of conifers from bark beetle attack.

Gillette’s other work is focused on assessing the 

effects of prescribed fires on the abundance and 

diversity of soil arthropods, like mites and spiders. 

In the future, Gillette will be collaborating 

with colleagues from the United States, China, 

and South Africa to document the types and 

relatedness of fungal pathogens that are carried 

by bark beetles. This work will allow scientists to 

identify new fungal strains carried by native and 

exotic beetles. 

Ask Her About

Bark beetle 

pheromones, 

beetle-fungal-host 

interactions, invasive 

species, effect of 

silviculture treatments 

on soil arthropods 

Background

Ph.D., forest 

entomology, 

University of 

California, 

Berkeley; member, 

Entomological

Society of America, 

Entomological

Society of Canada, 

International Society 

of Chemical Ecology

Wildlife and Aquatics
39

Carolyn Hunsaker

Research ecologist; Fresno, California

According to Carolyn Hunsaker, Sierra Nevada forests are the natural water tanks 

of California, with 60 percent of the state’s

water originating as small streams within the 

mountainous landscape. 

Hunsaker is a research ecologist who specializes 

in stream ecosystems, watersheds, and landscape 

ecology. Recently, she established an experimental 

watershed study in the Sierra Nevada that 

integrates the physical, chemical, and biological 

elements of the watershed and studies them over 

the long term. Her findings will not only generate 

new science, but help to address the design and 

financial challenges of conducting experiments 

at the landscape scale. 

She also was the first to publish on regional 

ecological risk assessment—particularly how it 

differs from conventional risk assessment—a 

result of invited work she conducted for the 

Environmental Protection Agency.

In the future, she plans to continue examining 

ecosystems holistically at the watershed scale, 

rather than as a series of disparate parts. She also 

will be evaluating approaches to managing forests 

that are subjected to multiple stressors, such as 

climate change and air pollution. 

Ask Her About

Forest and stream 

interactions, water 

and air quality, 

landscape ecology, 

forest ecosystem 

processes, ecological 

risk assessment, 

environmental 

monitoring 

Background

Doctorate of 

Environmental

Science and 

Engineering,

University of 

California, Los 

Angeles; member, 

Ecological Society

of America, 

International 

Association 

of Landscape 

Ecology, American

Geophysical Union 

Wildlife and Aquatics
40

Tracy Johnson

Research entomologist; Volcano, Hawaii

The amazing diversity of the world’s tens of millions of insect species and their interactions 

is what originally attracted Tracy Johnson to the 

field of entomology. What has sustained this 

research entomologist in the two decades since 

has been the opportunity to study those interactions 

in ways that make a real difference to people and 

the natural world.

Johnson’s research focuses on developing and 

evaluating biological control, or biocontrol, 

of nonnative invasive plants. Biocontrol is a 

management approach that involves the careful 

introduction of a plant-feeding insect or disease to 

control the growth or spread of an invasive plant. 

His work begins with targeting invasive plants 

that are most amenable to biocontrol, followed by 

careful evaluation of potential control agents and 

thorough assessment of their impacts following 

their release in the environment. 

In developing biocontrol agents as potential tools 

for management of key invasive plants, Johnson 

presents test results to state regulators, managers, 

and citizens. His recent work has focused on a 

highly host-specific natural predator of strawberry 

guava, a Brazilian tree that outcompetes native 

species. He also is directing collaborative studies 

with researchers in Costa Rica and Brazil to 

identify natural predators of Miconia, a tree that is 

widely recognized as the most threatening invasive 

plant in Hawaii and other Pacific Islands. 

Johnson enjoys the challenge of using the best 

available science to guide applications of biocontrol 

as a tool for managing invasive species—research 

that requires a long-term commitment given that 

typical projects may take 20 years or more from

start to finish. 

Ask Him About

Biological control 

(biocontrol) of invasive 

plants, insect ecology, 

post-release monitoring 

of biocontrol agents, 

impacts of biocontrol

Background

Ph.D., entomology, 

North Carolina State 

University; member, 

Entomological Society

of America, Hawaiian 

Entomological Society

Wildlife and Aquatics
41

Kathleen Matthews

Research aquatic ecologist; Albany, California

Kathleen Matthews, a research aquatic ecologist, studies high-elevation amphibians 

and fish—among the most imperiled species in the 

world, owing to both their biological characteristics 

and habitat requirements. Amphibians of all 

types are extremely sensitive to changes in their 

external environment, and those living in mountain 

ecosystems will likely be some of the first species 

affected by a warming climate. 

Much of Matthews’ research explores the impact of 

disturbances—like invasive species, cattle grazing, 

and climatic change—on amphibian and fish 

populations. Her work has helped, for example, to 

document the link between introduced trout and 

the decline of the native mountain yellow-legged 

frog in California’s Sierra Nevada. Her findings 

resulted in management changes, including 

reduced stocking for recreational fishing, removal 

of the trout in Sierra Nevada’s national parks, 

and restoration strategies for the declining frog. 

In subsequent studies, Matthews expanded her 

work to examine the link between fish stocking; 

potential climate change impacts, like a lowerthan-average snowpack; and mountain yellow-frog 

populations. She discovered that nonnative trout 

restricted frogs’ access to larger and deeper lakes, 

forcing them to breed in ponds that were prone 

to dry up in low snowpack years. This research 

highlights the cumulative impact of fish stocking 

and climate change.

In the future, Matthews intends to continue 

exploring the impact reduced snowpacks and 

warmer temperatures might have on high-elevation 

native species such as golden trout, the California 

state fish, and amphibians. 

Ask Her About

Native fish and 

amphibian ecology, 

habitat requirements 

for aquatic species, 

exotic trout, amphibian 

declines, the effect 

of climate change on 

native species in the 

Sierra Nevada

Background

Ph.D., fisheries, 

University of 

Washington; 

member, Ecological

Society of America, 

American Fisheries 

Society, Society for 

Conservation Biology 

Wildlife and Aquatics
42

Kathryn Purcell

Research wildlife biologist; Fresno, California

California’s beautiful and diverse landscapes are attractive to humans and wildlife alike. But, 

with the state’s exponential population growth and 

resulting conflicts, how can we best accommodate 

the needs of humans and wildlife? Research 

wildlife biologist Kathryn Purcell is exploring 

the conservation needs of wildlife species to help 

address this important question. 

One major emphasis of Purcell’s current research

is the fisher, a forest carnivore that has been 

extirpated from large portions of its historical 

range and that, as a result, is potentially vulnerable 

to extinction in some areas, like the southern 

Sierra Nevada. The important need to manage 

forest fuels to protect communities in the Sierra 

Nevada by reducing risk of catastrophic fire may 

alter the habitat elements critical to fishers, at least 

in the short term. Purcell’s research is addressing 

the effects of timber harvest and fuels treatments 

on fishers and their habitats. Her work involves a 

combination of live trapping and radio-collaring, 

most recently with miniaturized global positioning 

system collars that provide fine-scale data on 

movement patterns that, until now, have been 

impossible to collect. She also is using scatdetecting dogs, specially trained to locate fisher 

fecal matter, which can provide insights on habitat 

occupancy and use and which can be used as the 

basis for genetic analysis.

Another of her research emphases explores the 

habitat requirements needed to maintain healthy 

bird populations in the face of habitat degradation 

and destruction, invasive species, and climate 

change. She is particularly interested in the factors 

that affect bird abundance and reproductive success 

and the relationship between the two. 

Ask Her About

Bird habitat and nestsite selection, invasive 

species, fishers in 

the Sierra Nevada, 

wildlife response to 

habitat alteration 

Background

Ph.D., ecology, 

evolution, and 

conservation 

biology, University 

of Nevada, Reno

Wildlife and Aquatics
43

Steve Seybold

Research entomologist; Davis, California

Bark beetles are the most damaging pests of coniferous forests in the Northern Hemisphere 

and may, depending on the species, attack conifers 

and hardwoods in urban landscapes and in the 

wildland-urban interface. Understanding the 

biology, chemical ecology, and management of 

these important forest pests is critical to protecting 

future forest resources—and is exactly what drives 

Steve Seybold in his research. 

Seybold is a research entomologist who specializes 

in the study of bark and wood-boring beetles. He 

and his colleagues are characterizing the invasive 

bark beetle and woodborer fauna of California 

and other Western U.S. States. The discoveries 

and descriptions of the life histories and behaviors 

of these insects are an important first step to 

understanding their pest status in U.S. forests. 

Seybold and colleagues also were the first to isolate 

specific genes from bark beetles that the insects 

use to detoxify defense chemicals released by trees 

under attack. The isolation of these genes provides 

a site for the next generation of bark beetle control 

tools. 

In the future, Seybold plans to explore issues of 

drought and bark beetle-caused tree mortality, 

bark beetle and woodborer invasions of California’s 

national forests, and new threats to native oaks 

and walnuts. 

Ask Him About

Forest insect biology 

and management, 

bark beetles, woodboring beetles, insect 

pheromones, chemical 

ecology, invasive 

species, molecular 

biology, wood products 

entomology 

Background

Ph.D., entomological 

sciences, University 

of California, 

Berkeley; member, 

Entomological

Society of America, 

Entomological

Society of Canada, 

International Society 

of Chemical Ecology

Wildlife and Aquatics
44

Hartwell Welsh, Jr.

Research wildlife biologist; Arcata, California

A mphibians are in steep decline worldwide, representing the sixth—and what may 

very well be the greatest—wave of extinctions 

the planet has ever witnessed. Hartwell Welsh 

is conducting research aimed at preserving these 

unique creatures and highlighting their importance 

within ecosystems. 

Welsh has led studies on the use of amphibians as 

indicators of both terrestrial and aquatic ecosystem 

status. Amphibians are extremely sensitive to 

relatively small changes in microclimate and 

are habitat specialists highly adapted to specific 

environmental features. These characteristics allow 

them to serve as veritable barometers of ecosystem 

health and status. Most recently, Welsh developed 

a blueprint for using amphibians in Pacific 

Northwest streams to monitor their potential to 

support ecological services, such as production of 

commercially valuable salmonid species. 

In other studies, Welsh developed habitat 

models for many forest amphibians and reptiles 

of the Pacific Northwest. These models provide 

managers with a description of the habitat 

requirements of these species, which allow the 

managers to address human-caused stresses such 

as timber harvest and water diversions. One of

Welsh’s latest models was created using Forest 

Inventory and Analysis (FIA) data, a unique 

approach that was not initially envisioned within 

the FIA Program. 

Ask Him About

Amphibians as 

indicators of 

ecosystem status, 

link between 

amphibian and reptile 

distribution patterns 

and landscape 

processes, habitat 

modeling

Background

Ph.D., wildland 

resource sciences, 

University of 

California, Berkeley; 

member, Society for 

Conservation Biology, 

Society for the Study 

of Amphibians and 

Reptiles, American 

Society of Ichthyology 

and Herpetology

Wildlife and Aquatics
45

Peter Wohlgemuth

Hydrologist; Riverside, California

Peter Wohlgemuth subscribes to the belief that real-world problems are best solved by 

field research and that the best research, in turn, 

has management applications. Wohlgemuth is 

a hydrologist who studies postfire erosion and 

treatment strategies. 

In one study, Wohlgemuth found that prescribed 

fires reduce the soil erosion from subsequent 

wildfires, suggesting that prescribed burns may be 

a sediment management tool in addition to helping 

to manage vegetation or reduce fuel buildup. 

Wohlgemuth found that prescribed fires reduced 

postfire cleanup costs and, perhaps, even the need 

for expensive soil retention structures. 

In a second study, Wohlgemuth discovered that 

seeding with ryegrass is not an effective postfire 

erosion control measure, although the grass species 

has long been a standard erosion control plant 

in California. Wohlgemuth’s field tests revealed 

that ryegrass replaced, rather than augmented, 

the cover of postfire native regrowth and was no 

better at reducing erosion than unseeded controls. 

His findings helped to steer postfire management 

response away from seeding as an erosion-control 

technique.

In the future, Wohlgemuth—who enjoys working 

outdoors on real-world problems—will continue to 

quantify and model postfire sediment changes for 

planning and risk assessment. 

 

Ask Him About

Postfire erosion, 

sediment fluxes, 

geomorphology

Background

M.A., geography, 

California State 

University, Northridge; 

member, American 

Geophysical Union, 

Association for Fire 

Ecology 

Wildlife and Aquatics
46

William Zielinski 

Research ecologist; Arcata, California

William Zielinski is an expert on forest carnivores. His research explores two 

concurrent themes: understanding the effects of 

forest management on carnivorous mammals and 

developing survey and quantitative methods for 

studying mammals and biodiversity. Much of his 

work is centered on rare or threatened species, like 

the American marten and fisher.

In the future, Zielinski plans to continue 

his studies of forest management’s effects on 

biodiversity and help managers to reduce the 

likelihood of extinctions of threatened species. 

Ask Him About

Mammals, 

monitoring, 

noninvasive research 

methods, forest 

management, 

carnivores

Background

Ph.D., zoology 

and ecology, North 

Carolina State 

University; member, 

Ecological Society of

America, Society for 

Conservation Biology, 

American Society of 

Mammalogists

Wildlife and Aquatics
47

Glossary

An asterisk (*) indicates a term that is defined elsewhere in the glossary. 

A

adaptive management—approach in which findings and results of studies 

are continually incorporated into the management process so that it more 

accurately reflects reality and accommodates a dynamic system. 

amphibian—a cold-blooded species (which, thus, relies on the external 

environment for temperature regulation) that spends some portion of its life 

in water. See also ectotherm.* 

anadromous—a fish species that is born in freshwater, matures in marine 

(saltwater) ecosystems, and then returns to freshwater to reproduce.

anthropogenic—refers to changes or effects that are human-caused or in 

which people are otherwise closely involved. 

B

biocontrol—a management approach that involves the careful introduction 

of a host-specific insect or disease to reduce a pest population and its 

negative impacts.

biodiversity—variation in species or life forms within a landscape or 

ecosystem. Promoting biodiversity often is an objective of ecosystem 

management. 

biogeography—study of the geographic distributions of species and the 

factors that control them.

biomass—broadly defined, refers to the entire collection of living organisms 

and dead organic material an ecosystem supports; can include grasses, trees, 

insects, fish, birds, and mammals. More typically, is used in reference to the 

amount of living and dead vegetative material an ecosystem is capable of 

supporting. 

biopesticide—naturally occurring substances, such as fungal or plant 

extracts, that control pests. 

burn window—period during which prescribed burns should be ignited to 

maximize their efficacy and minimize undesirable effects. Burn windows 

typically occur within a set range of months each year but are subject to 

local weather conditions as well as other factors. 
48

C

carbon emissions—the release of carbon previously stored in trees into the 

atmosphere as a result of prescribed burning, wildfire, management activities, 

or forest thinning. 

carbon sequestration—the process by which forests or other vegetative 

landscapes remove and store carbon from the atmosphere. 

carbon stocks—refers to the entire supply of carbon stored within forests 

and other forms of terrestrial vegetation.

carnivore—a meat-eating species. 

conifer—a tree, usually evergreen, whose reproductive bodies (seeds) are 

contained within a cone.

crown—the upper portion of a tree or plant; ultimately forms the canopy.

D

deciduous—perennial plants that lose their foliage for part of the year.

disturbance—broad term referring to any event that disrupts an ecosystem 

and its components; includes fire, insect and disease outbreaks, and thinning. 

E

ecological risk assessment—systematic identification and evaluation of 

a single or a collection of risks (or threats) to individual species or entire 

ecosystems. 

ecology—a field of study concerned with the interactions of organisms and 

their environment.

ectotherm—a species that relies on the external environment for temperature 

regulation. 

ecosystem services—components of nature directly enjoyed, consumed, 

or used to yield human well-being; includes water, food and fiber, and 

biologically diverse natural land cover. 

emissions—in fire science, refers to the byproducts of fire that are put into 

the air; includes soot, carbon dioxide, water, and other compounds that are 

found in smoke.

eutrophication—An excessive influx of nutrients, like nitrogen, to a body of 

water that triggers a period of explosive plant growth. Typically, as the plants 

die and decompose, natural cycles and chemical balances are disrupted. 

extirpation—local extinction, or die-off, of a species that continues to persist 

in other parts of its range. 
49

F

fire adapted—refers to organisms or ecosystems that have historically 

experienced wildfire as a periodic disturbance agent and are resilient to 

its effects. 

fire behavior—refers to the growth, spread, and characteristics a wildfire 

exhibits. Fire behavior is influenced by a host of factors, including terrain 

and local weather conditions. 

fire exclusion—strategy in which fire is actively avoided, usually by means 

of suppressing lightning or human-caused ignitions. 

fire history—historical pattern and characteristics of wildfire in an ecosystem. 

Often, a useful consideration when managing fire-adapted* landscapes.

flammability—refers to the ability of fuel* to burn and the resulting intensity. 

forb—a nonwoody flowering plant that is not a grass; includes legumes. 

fuel—in fire science, refers to organic matter that can burn in a fire; includes 

live and dead standing trees, dead and downed logs and branches, pine 

needles, leaves, grasses, and shrubs. 

fuel consumption—in fire science, the process by which fire converts fuel* 

to energy (heat) and combustion byproducts, such as ash, charcoal, and 

smoke or emissions. Knowledge of the amount and rate of fuel consumption 

can help to predict fire effects, intensity, and severity.

fuel reduction—management activity in which fuel* is altered or altogether 

removed to lower the likelihood, intensity, or severity of wildfire.

G

gene—molecular unit that carries a species’ genetic material. 

genome—the entire collection of a species’ genetic material. 

genomics—the study of the genomes* and genes* of species. 

geomorphology—the study of the processes that shape the physical features 

of the Earth.

H

habitat—the place where a species lives and where it finds the specific 

kinds of food, shelter, and other components necessary for its survival 

and successful reproduction. 

hardwood—a deciduous,* non-conifer* tree; such as maple, alder, and willow.

heterogeneity—variation or diversity in condition or state. 
50

I

indicator species—a species that is intimately associated with one or more 

of an ecosystem’s components. The presence and abundance of an indicator 

species in an ecosystem can be an indication of that ecosystem’s health as well 

as the presence or abundance of other species in the ecosystem.

integrated resource management—management of various resource values so 

that they are utilized in the combination that best meets present and future 

needs.

invasive species—species that occur outside of their native range and that are 

detrimental to the new ecosystems they inhabit; includes plants, animals, and 

pathogens.*

L

land use—the use (purpose) to which land is put by people; includes protected 

areas, plantations, pastures, and human settlements. 

landscape ecology—study of how ecological patterns and processes interact 

across space (landscapes). 

long-term ecosystem productivity—managing ecosystems to provide goods 

and services without reducing the land’s capability to provide that rate of 

production in the future. 

M

meteorology—the study of weather and climate patterns and phenomena. 

microclimate—refers to local-level (small-scale) climatic conditions, such as 

the temperature and humidity within a forested stand. 

P

pathogen—a disease-causing agent; includes bacteria, viruses, and fungi.

pathology—the study of diseases, their causes, and distribution. 

phenology—study of the life history characteristics of a species, particularly 

as they are related to time of the year. 

pheromone—naturally occurring chemicals that insects and related species 

emit to communicate with one another. Typically odorless to people, 

pheromones can be harvested and synthetically created to influence insect 

behavior. 

pioneer plant—plant that is adapted to colonize and grow in a site following 

a disturbance.* 
51

prescribed fire—a fire that is intentionally set and carefully monitored to 

achieve certain management objectives, like reducing a landscape’s fuel* load. 

Also referred to as a prescribed burn. 

R

range shift—phenomenon in which the historical or native range of a species 

expands or retracts in response to climatic variability and change. 

recolonization—process in which a species returns to an area it once 

inhabited; may occur rapidly or gradually over time. 

resilience—used in reference to ecosystems that are capable of withstanding 

or favorably recovering from disturbance,* such as insect outbreaks or fire. 

restoration—strategy in which an ecosystem is actively managed to return it 

to a previous or sustainable condition or state. 

riparian—an ecosystem bordering a stream, river, or lake that is strongly 

influenced by the adjacent body of water. 

S

semiochemical—chemicals produced by one organism that produce an 

effect, usually behavioral, in another organism. In forest pest management, 

semiochemicals are applied to individual host trees or forest stands to 

discourage pest infestation. 

seral—refers to a stage of forest development. Early seral (also known as early

successional) refers to relatively young forests with simple attributes; late 

seral (also known as late successional) refers to mature forests with complex 

attributes, such as coarse woody debris, snags,* and spatial heterogeneity.*

silviculture—the science of controlling the vegetation, growth, composition, 

and health of forests to meet the objectives of landowners. 

snag—standing dead tree. 

spatial heterogeneity—typically refers to variation in the amount and 

diversity of trees, shrubs, and understory plants at various vertical and 

horizontal areas within a forest. High levels of spatial heterogeneity are 

believed important for healthy, resilient* forests. 

spatial scale—the resolution of the scale of reference; includes individual 

tree, stand, and landscape scales. 

special forest product—a harvestable nontimber forest product that has 

commercial, medicinal, or craft value; includes mushrooms and floral greens.

stand—in forestry and silviculture, refers to a contiguous group of trees 

of relatively similar age, composition, and structure, so as to be a 

distinguishable unit. 
52

stressor—a physical or biological component that reduces the vigor of 

organisms or ecosystems and potentially reduces their resilience* to other 

stressors; includes invasive species,* contaminants, drought, and fungal 

pathogens.* 

succession—the growth and change of a forest over time and the 

replacement of an earlier stage of development with a newer phase 

(as in early seral* to late seral*).

T

temporal scale—the scale of reference that refers to the distribution of a 

variable across time; includes daily, monthly, and annual resolution of data. 

thinning—the removal of some, but not all, trees or vegetation in a forest 

or landscape. 

treatment—a forest management intervention applied to achieve a particular 

objective; includes fuel* treatments. 

U

understory—the lower, or ground, portion of a forest; often consists of 

grasses, shrubs, and immature trees. 

ungulate—hoofed plant-eating species, such as feral pigs and deer. 

urbanization—a land use* change involving the conversion of rural lands 

(such as agricultural land) to developed areas (such as residential areas or 

commercial sites). Urban and developed areas consist of residential, industrial, 

commercial, and institutional lands. 

W

watershed—the part of a landscape where precipitation flows into a single 

river system. 

wildland-urban interface (WUI)—area at which a wildland (such as a forest, 

range, or woodland) intersects with a developed area, such as a residential 

community. As urbanization* continues and expands into wildlands, the 

WUI grows, often translating into an increased risk of severe wildfires, as 

human lives and structures become involved.
53

Beyers, Jan ..................................... 9

Bytnerowicz, Andrzej ...................10

Chavez, Deborah ........................... 5

Chen, Shyh-Chin ........................ 11

Cordell, Susan.............................. 19

Fettig, Christopher....................... 37

Frankel, Susan ............................. 20

Fujioka, Francis ........................... 12

Giardina, Christian ..................... 21

Gillette, Nancy ............................ 38

Groover, Andrew ......................... 22

Hipkins, Valerie ........................... 23

Hughes, Richard Flint ................ 24

Hunsaker, Carolyn ...................... 39

Johnson, Tracy ............................. 40

Knapp, Eric ................................. 13

Matthews, Kathleen .................... 41

Millar, Constance ....................... 14

Index by Scientist

Mori, Sylvia ................................. 25

North, Malcolm .......................... 26

Padgett, Pamela ........................... 27

Peper, Paula ................................. 28

Preisler, Haiganoush ................... 29

Purcell, Kathryn .......................... 42

Ritchie, Martin............................ 30

Scowcroft, Paul ............................ 31

Seybold, Steve .............................. 43

Simpson, Jim ............................... 15

Skinner, Carl ............................... 32

Weise, David ............................... 16

Welsh, Hartwell, Jr. .................... 44

Winter, Patricia ............................. 6

Wohlgemuth, Peter ..................... 45

Zhang, Jianwei ............................. 33

Zielinski, William ....................... 46
54

A

Air

pollution ....................................10

quality .................................15, 39

 fire effects on .........................10

Amphibians

as indicators of

 ecosystem status ......................44

decline of ..................................41

ecology of ..................................41

general ......................................44

Aquatic species

habitat .......................................41

B

Beetles

bark........................................37, 43

 economic importance of.........37

 managing . ...............................37

 monitoring ..............................37

 pheromones of.........................38

interactions with fungi 

 and hosts .................................38

wood-boring .............................43

Behavior

environmentally responsible,

 increasing ..................................6

Biological control .........................40

agents, post-release 

 monitoring of ..........................40

impacts ......................................40

of invasive plants .......................40

Biology

molecular ..................................43

Biomass ........................................28

mapping ....................................24

Biometrics ....................................30

Bird

habitat .......................................42

nest-site selection ......................42

C

Carbon

cycle ..........................................21

forest .........................................26

managing forests for .................33

sequestration .............................22

Carnivores ....................................46

Chaparral 

response to fire ...........................9

Climatology

fire .............................................12

Climate

change ............... 10, 15, 21, 26, 32

 management amidst ..............14

 relationship with 

 forest diseases ......................20

dynamics ...................................11

effects on native species ............41

forecasts ....................................11

regional .....................................11

Computing

statistical ...................................25

Conservation

genetic .......................................23

Index by Subject
55

D

Data

spatial ........................................29

temporal ....................................29

Disease

forest ........................................20

types of

 sudden oak death ...................20

Disturbance

general ......................................13

 effects of ................................13

E

Ecological risk assessment ............39

Ecology

amphibian .................................41

chemical ....................................43

ecosystem ..................................21

fire ............................................13

functional ..................................19

insect .........................................40

landscape ..................................39

native fish .................................41

tree physiology ..........................33

wildlife ......................................31

Ecophysiology ..............................19

Ecosystems

ecology ......................................21

health of ....................................26

restoring processes in .......... 19, 21

status of 

 amphibians as indicators of ...44

terrestrial ..................................31

Energy

use, effects of urban trees on ....15

Environmental

monitoring ................................39

Erosion

following fire ............................45

Ethnicity

studies of .....................................5

Experiments

design of ...................................25

F

Fire

behavior ....................................16

climatology .........................12, 32

danger .......................................11

effects

 on air quality .........................10

 on animals .............................13

 on chaparral ............................9

 on forest health .....................37

 on plants ................................13

ecology ................................13, 32

erosion following ......................45

general ......................................26

history .......................................32

interactions with silviculture ....13

meteorology ..............................12

modeling .............................12, 16

patterns of .................................13

prescribed ............................16, 37

rehabilitation following ..............9

response of rare species to ...........9

Fish

exotic species of

 trout .......................................41

native species of ........................41

 ecology ..................................41

Fishers ..........................................42
56

Forest

carbon .......................................26

change .......................................13

diseases

 relationship with 

 climate change ....................20

ecosystem processes ..................39

growth ......................................30

Hawaiian ..................................31

insect

 biology ...................................43

 management ..........................43

interactions with streams ..........39

management .......................26, 46

amidst changing climate .......14

 for carbon ..............................33

modeling ...................................30

native

 Hawaii ...................................31

pathology ..................................20

restoration ...........................26, 31

subalpine ...................................14

threats

 risk assessment of ..................29

tropical ......................................19

urban .........................................15

yield ..........................................30

Fuel

general ......................................26

management strategies .......13, 32

moisture ....................................16.

treatments

 effects on forest health ..........37

 effects on invasive species ........9

Fungi

interaction with beetles .............38

G

Genetics

conservation ..............................23

molecular ..................................23

plant ....................................22, 23

tree ........................................... 22

Genomics .....................................22

Geomorphology ...........................45

Glaciers 

rock ...........................................14

Growth

of forests ....................................30

H

Habitat

alteration

 wildlife response to ...............42

bird ............................................42

models .......................................44

Hawaii

ecosystems ..........................19, 24

invasive species in .....................24

native forests .......................24, 31

 restoration of .........................31

I

Insect

biology ......................................43

ecology ......................................40

management .............................43

pheromones ...............................43

types of

 bark beetles ................ 37, 38, 43

 wood-boring beetles ..............43
57

Invasive 

plants ........................................27

 biological control of ...............40

 mechanisms for 

 control of .......................27, 40

 mechanisms of invasion ........27

species ...............20, 24, 38, 42, 43

 effects on fire ...........................9

K

Koa ...............................................31

L

Landscape ecology .................32, 39

Law enforcement ............................5

M

Mammals .....................................46

Management 

beetle .........................................37

forest ...................................26, 46

land

 role of trust in ..........................6

recreation ....................................6

Models

fire ......................................12, 16

forest .........................................30

habitat .......................................44

stand growth .............................33

statistical ...................................25

vegetation ..................................16

weather .....................................12

Monitoring

beetle .........................................37

biocontrol agents .......................40

environmental ...........................39

general ......................................46

large-scale .................................25

Mountains

Great Basin ...............................14

Sierra Nevada ............................14

N

Nitrogen

deposition .................................27

 in atmosphere and soils .........27

Nutrient storage and cycling ........24

P

Pacific Island ecosystems .............19

invasive species in .....................24

Pathology

forest .........................................20

Pheromones

insect .........................................43

Pikas .............................................14

Plants

effects of soil on ........................27

genetics .....................................23

invasive .....................................27

 mechanisms for 

 control of .......................27, 40

mineral nutrition of ..................27

Pollution

air ..............................................10
58

Q

Quality

air ..............................................39

water .........................................39

R

Race

studies of .....................................5

Recreation

day-use ........................................5

management ...............................6

nature-based ...............................5

Rehabilitation

following fire ..............................9

Reptiles

general ......................................44

Research

noninvasive methods for ...........46

Restoration

ecosystem ..................................21

forest ...................................26, 31

Risk assessment

ecological ..................................39

forest threats .............................29

S

Sampling

design of ...................................25

Sediment ......................................45

Sierra Nevada

fisher communities in ...............42

native species in ........................41

Silviculture

effects on soil arthropods ..........38

general ......................................33

interactions with fire ................13

of interior pine forests ...............30

of mixed-conifer forests ............30

Soil

arthropods ................................38

 effects of silviculture 

 treatments on ......................38

effects on plant communities ....27

Stand

growth models ..........................33

Statistical methods

general ................................25, 29

Streams 

interactions with forests ............39

Subalpine forests 

general ......................................14

response to climate change .......14

Sudden oak death .........................20

T

Trails ..............................................5

Tree

disease

 sudden oak death ...................20

ecology ......................................33

genes .........................................22

physiology .................................33

types of

 ponderosa pine ......................30

urban .........................................28

 measurement and growth ......28

 site assessment .......................28
59

Trout

exotic .........................................41

U

Ungulates

wild

 ecological impacts of .............31

Urban 

communities

 communicating with ...............6

forests

 effects on energy use .............15

trees ..........................................28

 assessing sites for ...................28

 measurement and 

 growth of .............................28

V

Vegetation

competition among ...................33

models .......................................16

W

Water

quality .......................................39

Weather

forecasts ....................................11

monitoring ................................12

Wildlife

ecology ................................31, 42

Wood

boring beetles ............................43

development ..............................22

genes regulating 

 development of ........................22

products entomology ................43

Y

Yield

of forests ....................................30
60

Notes
Writer Yasmeen Sands

Design Yasmeen Sands and Keith Routman

Layout Keith Routman

March 2011
March 2011

http://www.fs.fed.us/psw/