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David A Pyke

I am a scientist emeritus at the Forest and Rangeland Ecosystem Science Center. My research interests include population ecology of native and invasive plants in the Intermountain West, monitoring protocols for ecosystem integrity on wild lands, and restoration ecology of native plants on disturbed and invaded lands.

I am involved with a few of my former projects. I am completing the ten-year analysis of the SageSTEP sagebrush – cheatgrass sites. I plan to assist and continue to provide guidance to new scientists who are now leading this long-term project. I am providing guidance and insights for two other on-going projects - The Field of Sagebrush Dreams project and the Mojave grazing removal project. Field of Dreams is an attempt to transplant sagebrush and create patches of sagebrush that will be used by Greater Sage-grouse for nesting within 5 years of a fire removing sagebrush from former nesting sites. The Mojave project is examining vegetation changes after livestock grazing was removed from locations on the Mojave National Preserve 20 years ago. Amongst these interests, my wife and I plan to travel in our teardrop trailer and see other landscapes in the US and Canada and to travel internationally to enjoy new cultures. In addition, we plan to make regular visits to our home in Honolulu.

Professional Experience

  • 1996 – 2021: Supervisory Research Ecologist, U.S. Geological Survey, Forest & Rangeland Ecosystem Science Center, Corvallis, OR

  • 1996 – 1999: Assistant Center Director, U.S. Geological Survey, Forest & Rangeland Ecosystem Science Center, Corvallis, OR

  • 1993 – 1996: Research Rangeland Ecologist, National Biological Survey/Service, Forest & Rangeland Ecosystem Science Center, Corvallis, OR

  • 1992 – 1993: Research Rangeland Ecologist, Bureau of Land Management, Pacific Forest & Basin Rangeland Systems Cooperative Research & Technology Unit, Corvallis, OR

  • 1987 – 1992: Assistant Professor, Department of Range Science, Utah State University, Logan, UT

Education and Certifications

  • Ph.D., Botany, Washington State University, Pullman, WA (1983)

  • M.S., Forest and Range Management, Washington State University, Pullman, WA (1977)

  • B.S., Range Management (Wildlife option), Washington State University, Pullman, WA (1976)

Affiliations and Memberships*

  • Ecological Society of America

  • British Ecological Society

  • Society for Ecological Restoration

  • Society for Range Management

Science and Products

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cheatgrass

Cheatgrass and Medusahead

Invasive annual grasses, such as cheatgrass (Bromus tectorum) and medusahead (Taeniatherum caput-medusae), are one of the most significant stressors to rangeland ecosystems in the western U.S. Their expansion and dominance across this area are the most damaging ecosystem agents on this iconic landscape.
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Ecosystems Mission Area, Biological Threats and Invasive Species Research Program, Land Management Research Program, Forest and Rangeland Ecosystem Science Center
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Cheatgrass and Medusahead

Invasive annual grasses, such as cheatgrass (Bromus tectorum) and medusahead (Taeniatherum caput-medusae), are one of the most significant stressors to rangeland ecosystems in the western U.S. Their expansion and dominance across this area are the most damaging ecosystem agents on this iconic landscape.
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SageSTEP fieldwork

Standardized Emergency Stabilization and Rehabilitation Monitoring Protocols (ES&R)

Fire rehabilitation programs have existed within federal agencies since the early 1960s. The U.S. Forest Service and Bureau of Land Management are the largest users of emergency stabilization and rehabilitation (ES&R) funds, but these agencies only sporadically implement proposed monitoring and rarely use common protocols. As a result, it is impossible to draw scientifically credible conclusions...
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Land Management Research Program, Forest and Rangeland Ecosystem Science Center
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Standardized Emergency Stabilization and Rehabilitation Monitoring Protocols (ES&R)

Fire rehabilitation programs have existed within federal agencies since the early 1960s. The U.S. Forest Service and Bureau of Land Management are the largest users of emergency stabilization and rehabilitation (ES&R) funds, but these agencies only sporadically implement proposed monitoring and rarely use common protocols. As a result, it is impossible to draw scientifically credible conclusions...
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truck and camper trailer Onaqui SageStep field site

Restoration and Ecology of Arid Lands Team (FRESC)

The focus of our research is on the restoration and monitoring of the plants and soils of the Intermountain West. Our lab is part of the Snake River Field Station, but is located in Corvallis, Oregon. Research topics include fire rehabilitation effects and effectiveness, indicators of rangeland health, invasive species ecology, and restoration of shrub steppe ecosystems.
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Ecosystems Mission Area, Land Management Research Program, Forest and Rangeland Ecosystem Science Center
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Restoration and Ecology of Arid Lands Team (FRESC)

The focus of our research is on the restoration and monitoring of the plants and soils of the Intermountain West. Our lab is part of the Snake River Field Station, but is located in Corvallis, Oregon. Research topics include fire rehabilitation effects and effectiveness, indicators of rangeland health, invasive species ecology, and restoration of shrub steppe ecosystems.
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Seed drill on a restoration research site

Restoration of Shrub Steppe Ecosystems

This research theme provides land managers information to help them make restoration decision at local and landscape scales.
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Ecosystems Mission Area, Land Management Research Program, Sage-grouse & Sagebrush Ecosystem (unpublished), Forest and Rangeland Ecosystem Science Center
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Restoration of Shrub Steppe Ecosystems

This research theme provides land managers information to help them make restoration decision at local and landscape scales.
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USGS science for a changing world

Invasive Species Ecology

Invasive annual grasses are the greatest threat to shrub-grassland ecosystems of the Intermountain West. These grasses grow earlier in the season than native plants, usurping water and nutrients, and making survival and reproduction difficult for native species. They also change the fire regime within the ecosystem, creating more frequent and larger wildfires. We are attempting to understand the...
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Biological Threats and Invasive Species Research Program, Forest and Rangeland Ecosystem Science Center
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Invasive Species Ecology

Invasive annual grasses are the greatest threat to shrub-grassland ecosystems of the Intermountain West. These grasses grow earlier in the season than native plants, usurping water and nutrients, and making survival and reproduction difficult for native species. They also change the fire regime within the ecosystem, creating more frequent and larger wildfires. We are attempting to understand the...
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USGS science for a changing world

Indicators of Rangeland Health

Rangelands are natural ecosystems where the native vegetation consists predominantly of grasses, grass-like plants, forbs, or shrubs. Rangelands include natural grasslands, savannas, shrublands, oak and pinyon-juniper woodlands, many deserts, tundra, alpine communities, marshes, and wet meadows.
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Land Management Research Program, Species Management Research Program, Forest and Rangeland Ecosystem Science Center
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Indicators of Rangeland Health

Rangelands are natural ecosystems where the native vegetation consists predominantly of grasses, grass-like plants, forbs, or shrubs. Rangelands include natural grasslands, savannas, shrublands, oak and pinyon-juniper woodlands, many deserts, tundra, alpine communities, marshes, and wet meadows.
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USGS science for a changing world

Fire Rehabilitation Effects and Effectiveness

Mitigation of ecological damage caused by rangeland wildfires focuses on conservation of ecosystem function through reducing soil erosion and spread of invasive plants. The overall effectiveness of these treatments is variable, and their necessity has been debated recently. We conduct research projects and synthesize findings to determine if mitigation treatments: 1) protect ecosystems against...
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Forest and Rangeland Ecosystem Science Center
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Fire Rehabilitation Effects and Effectiveness

Mitigation of ecological damage caused by rangeland wildfires focuses on conservation of ecosystem function through reducing soil erosion and spread of invasive plants. The overall effectiveness of these treatments is variable, and their necessity has been debated recently. We conduct research projects and synthesize findings to determine if mitigation treatments: 1) protect ecosystems against...
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Sagebrush on fire in a controlled burn

Field of Sagebrush Dreams: Sage-grouse Responses to Burns and Sagebrush Restoration in Fire-Impacted Landscapes

Fire can reduce sage-grouse habitat, diminish local and regional population sizes, and result in the fragmentation of sage-grouse populations. Research is needed to identify the best ways to restore sagebrush to support sage-grouse demography, persistence, and space use.
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Land Management Research Program, Forest and Rangeland Ecosystem Science Center, Fort Collins Science Center, Western Ecological Research Center (WERC)
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Field of Sagebrush Dreams: Sage-grouse Responses to Burns and Sagebrush Restoration in Fire-Impacted Landscapes

Fire can reduce sage-grouse habitat, diminish local and regional population sizes, and result in the fragmentation of sage-grouse populations. Research is needed to identify the best ways to restore sagebrush to support sage-grouse demography, persistence, and space use.
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USGS science for a changing world logo

Climate change and ecohydrology in temperate dryland ecosystems: a global assessment

Water cycling and availability exert dominant control over ecological processes and the sustainability of ecosystem services in water - limited ecosystems. Consequently, dryland ecosystems have the potential to be dramatically impacted by hydrologic alterations emerging from global change, notably increasing temperature and altered precipitation patterns. In addition, the possibility of directly m
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John Wesley Powell Center for Analysis and Synthesis
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Climate change and ecohydrology in temperate dryland ecosystems: a global assessment

Water cycling and availability exert dominant control over ecological processes and the sustainability of ecosystem services in water - limited ecosystems. Consequently, dryland ecosystems have the potential to be dramatically impacted by hydrologic alterations emerging from global change, notably increasing temperature and altered precipitation patterns. In addition, the possibility of directly m
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If you are unable to access or download a product, email fresc_outreach@usgs.gov a request, including the full citation, or call (541) 750-1030.

Sagebrush Restoration Following Fire Disturbance in the Virginia Mountains, Nevada (2018)

We developed a framework that strategically targets burned areas for restoration actions (e.g., seeding or planting sagebrush) that have the greatest potential to positively benefit Greater Sage-grouse (Centrocercus urophasianus; hereafter sage-grouse) populations through time. Specifically, we estimated sagebrush (Artemisia Spp.) recovery following wildfire and risk of non-native annual grass inv
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Western Ecological Research Center (WERC)

Invasive Grasses Cheatgrass and Medusahead Yield Responses to Sucrose in Experimental Plots in the Northern Great Basin, USA Dataset, 2005-2006

Comma-separated values (.csv) files containing data related to plant biomass and seed production responses of invasive Bromus tectorum (cheatgrass) and Taeniatherum caput-medusae (medusahead) to varying sucrose treatments.
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Forest and Rangeland Ecosystem Science Center

Tackifier impacts on growth of Great Basin mosses Bryum argenteum and Syntrichia ruralis, a growth chamber study, 2017-2018

The dataset supports a larger study that examined the impacts of three tackifiers (guar, psyllium, and polyacrylamide) on growth of two dryland mosses (Bryum argenteum and Syntrichia ruralis). Moss fragments were grown in petri dishes and subjected to individual tackifiers in one of three possible concentrations (0.5x, 1x, or 2x) of the respective manufacturer's recommended application rate. Disti
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Forest and Rangeland Ecosystem Science Center

Compilation of BLM Monitoring Reports Assessing Post Wildfire Seeding of Rangelands, 2001-2009

Post-fire rehabilitation seeding in the U.S. Intermountain West, primarily conducted by the Bureau of Land Management, is designed to reduce the risk of erosion and weed invasion while increasing desirable plant cover. Seeding effectiveness is typically monitored for three years following treatment, after which a closeout report is prepared. We evaluated 220 third-year closeout reports describing
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Forest and Rangeland Ecosystem Science Center

Compilation of studies assessing post-wildfire seeding of rangelands worldwide (1965-2010)

Mitigation of ecological damage caused by rangeland wildfires has historically been an issue restricted to the western United States. It has focused on conservation of ecosystem function through reducing soil erosion and spread of invasive plants. Effectiveness of mitigation treatments has been debated recently. We searched for literature on postfire seeding of rangelands worldwide. Literature dat
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Forest and Rangeland Ecosystem Science Center
USGS
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Image: Big Sagebrush Re-establishing 15 Years Post-wildfire Along the Boise Front Mountains
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If you are unable to access or download a product, email fresc_outreach@usgs.gov a request, including the full citation, or call (541) 750-1030.

Filter Total Items: 108

Ten-year ecological responses to fuel treatments within semiarid Wyoming big sagebrush ecosystems

Sagebrush ecosystems of western North America are threatened by invasive annual grasses and wildfires that can remove fire-intolerant shrubs for decades. Fuel reduction treatments are used ostensibly to aid in fire suppression, conserve wildlife habitat, and restore historical fire regimes, but long-term ecological impacts of these treatments are not clear. In 2006, we initiated fuel reduction tre
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Ecosystems Mission Area, Land Management Research Program, Forest and Rangeland Ecosystem Science Center

Targeting sagebrush (Artemisia spp.) restoration following wildfire with Greater Sage-Grouse (Centrocercus urophasianus) nest selection and survival models

Unprecedented conservation efforts for sagebrush (Artemisia spp.) ecosystems across the western United States have been catalyzed by risks from escalated wildfire activity that reduces habitat for sagebrush-obligate species such as Greater Sage-Grouse (Centrocercus urophasianus). However, post-fire restoration is challenged by spatial variation in ecosystem processes influencing resilience to dist
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Ecosystems Mission Area, Fort Collins Science Center, Western Ecological Research Center (WERC)

Fuel reduction treatments reduce modeled fire intensity in the sagebrush steppe

Increased fire size and frequency coupled with annual grass invasion pose major challenges to sagebrush (Artemisia spp.) ecosystem conservation, which is currently focused on protecting sagebrush community composition and structure. A common strategy for mitigating potential fire is to use fuel treatments that alter the structure and amount of burnable material, thus reducing fire behavior and cre
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Ecosystems Mission Area, Land Management Research Program, Forest and Rangeland Ecosystem Science Center

Sagebrush recovery patterns after fuel treatments mediated by disturbance type and plant functional group interactions

Fire and fuel management is a high priority in North American sagebrush ecosystems where the expansion of piñon and juniper trees and the invasion of nonnative annual grasses are altering fire regimes and resulting in loss of sagebrush species and habitat. We evaluated 10-yr effects of woody fuel treatments on sagebrush recruitment and plant functional group interactions using Sagebrush Steppe Tre
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Ecosystems Mission Area, Land Management Research Program, Forest and Rangeland Ecosystem Science Center

Interpreting Indicators of Rangeland Health, Version 5: Bureau of Land Management Technical Reference 1734-6

The Interpreting Indicators of Rangeland Health (IIRH) protocol is designed for assessing ecosystem function on rangelands and woodlands. The protocol was developed by an interagency cadre of technical experts and has been in use by for two decades. The protocol is well accepted and is a valuable tool for communicating rangeland conditions with stakeholders. Technical Reference 1734-6 Version 4,
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Ecosystems Mission Area, Forest and Rangeland Ecosystem Science Center

Postfire growth of seeded and planted big sagebrush - Strategic designs for restoring Greater Sage-grouse nesting habitat

Wildfires change plant community structure and impact wildlife habitat and population dynamics. Recent wildfire‐induced losses of big sagebrush (Artemisia tridentata) in North American shrublands are outpacing natural recovery and leading to substantial losses in habitat for sagebrush‐obligate species such as Greater Sage‐grouse. Managers are considering restoration strategies that include plantin
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Ecosystems Mission Area, Land Management Research Program, Forest and Rangeland Ecosystem Science Center, Southwest Biological Science Center, Western Ecological Research Center (WERC)

Biological soil crusts in ecological restoration: Emerging research and perspectives

Drylands encompass over 40% of terrestrial ecosystems and face significant anthropogenic degradation causing a loss of ecosystem integrity, services, and deterioration of social‐ecological systems. To combat this degradation, some dryland restoration efforts have focused on the use of biological soil crusts (biocrusts): complex communities of cyanobacteria, algae, lichens, bryophytes, and other or
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Ecosystems Mission Area, Forest and Rangeland Ecosystem Science Center, John Wesley Powell Center for Analysis and Synthesis

Components and predictors of biological soil crusts vary at the regional vs. plant community scales

Although biological soil crusts (biocrusts) occur globally in arid and semi-arid environments, most of our knowledge of biocrust cover and ecology is from a relatively small number of locations worldwide. Some plant communities are known to have high cover of biocrusts, but the abundance of biocrusts is largely undocumented in most plant communities. Using a data driven approach, we identified 16
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Ecosystems Mission Area, Forest and Rangeland Ecosystem Science Center

Weed-suppressive bacteria applied as a spray or seed mixture did not control Bromus tectorum

We conducted two case studies testing effectiveness of a soil-borne bacteria, Pseudomonas fluorescens strain D7, in controlling Bromus tectorum (cheatgrass) and in affecting the density of sown desirable seedlings. We conducted two case studies testing D7’s ability to control of B. tectorum (cover, biomass and density) when mixed with native seeds sown after a fire and when sprayed on a native com
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Ecosystems Mission Area, Forest and Rangeland Ecosystem Science Center

Context-dependent effects of livestock grazing in deserts of western North America

This chapter provides a general review of grazing disturbance by large mammalian grazers and the role of ecological context in moderating its effects, with emphasis on North American deserts. It discusses the ecological consequences of cessation of livestock grazing and present a case study from the Mojave Desert, United States of America. A primary effect of grazing is selective removal and inges
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Ecosystems Mission Area, Forest and Rangeland Ecosystem Science Center, Northern Rocky Mountain Science Center

Passive restoration of vegetation and biological soil crusts following 80 years of exclusion from grazing across the Great Basin

Restoration targets for biological soil crusts are largely unknown. We surveyed seven 80‐year‐old grazing exclosures across northern Nevada for biocrusts to quantify reference conditions at relatively undisturbed sites. Exclosures were associated with the following plant communities: Wyoming big sagebrush, black sagebrush, and areas co‐dominated by winterfat and Wyoming big sagebrush. Cover of bio
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Ecosystems Mission Area, Forest and Rangeland Ecosystem Science Center

Hydroseeding tackifiers and dryland moss restoration potential

Tackifiers are long‐chain carbon compounds used for soil stabilization and hydroseeding and could provide a vehicle for biological soil crust restoration. We examined the sensitivity of two dryland mosses, Bryum argenteum and Syntrichia ruralis, to three common tackifiers ‐ guar, psyllium, and polyacrylamide (PAM) ‐ at 0.5x, 1.0x, and 2.0x of recommended (x) concentrations for erosion control and
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Ecosystems Mission Area, Forest and Rangeland Ecosystem Science Center

Non-USGS Publications**

Francis, M.G., Pyke, D.A., 1996, Crested wheatgrass-cheatgrass seedling competition in a mixed-density design: Journal of Range Management, v. 49, no. 5, p. 432-438.
Tanaka, J.A., Pyke, D.A., 1996, Introduction to the Sustaining Rangeland Ecosystems Symposium In Edge, W.D., Olson-Edge, S.L., eds., Proceedings of the Sustaining Rangeland Ecosystems Symposium: Special Report 953, Corvallis, OR, Oregon State University, Agricultural Experiment Station, p. 1-2.
Huber-Sannwald, E., Pyke, D.A., Caldwell, M.M., 1996, Morphological plasticity following species-specific recognition and competition in two perennial grasses: American Journal of Botany, v. 83, no. 7, p. 919-931.
Pyke, D.A., 1995, Population diversity with special reference to rangeland plants In West, N.E., ed., Biodiversity of Rangelands: Logan, Utah, College of Natural Resources, Utah State University, p. 21-32.
Pyke, D.A., Novak, S.J., 1994, Cheatgrass demography-establishment attributes, recruitment, ecotypes, and genetic variability: U.S. Department of Agriculture, Forest Service, Intermountain Research Station General Technical Report INT-GTR-313, p. 12-21.
Pyke, D.A., 1994, Ecological significance of seed banks with special reference to alien annuals: U.S. Department of Agriculture, Forest Service, General Technical Report INT-GTR-313, p. 197-201.
Borman, M.M., Pyke, D.A., 1994, Successional theory and the desired plant community approach: Rangelands, v. 16, no. 2, p. 82-84.
Pyke, D.A., Borman, M.M., 1993, Problem analysis for the Vegetation Diversity Project - A research and demonstration program to restore and maintain native plant diversity on deteriorated rangelands of the Great Basin and Columbia Plateau: US, Bureau of Land Management, Oregon State Office Technical Note OR-936-01, p. 100.
Pyke, D.A., Thompson, J.N., 1986, Statistical analysis of survival, and removal rate experiments: Ecology, no. 67, p. 240-245.

**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.

Filter Total Items: 17
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Sagebrush Recovery Patterns after Fuel Treatments Affected by Disturbance Type and Plant Functional Group Interactions

Researchers evaluated 10-year effects of fuel treatments on sagebrush recruitment and plant functional group interactions using Sagebrush Treatment...

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Interpreting Indicators of Rangeland Health – Version 5

Qualitative assessments of rangeland health using observable indicators help managers make informed land management decisions and communicate findings...

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Post-Fire Growth of Seeded and Planted Big Sagebrush – Strategic Designs for Restoring Greater Sage-grouse Nesting Habitat

Recent wildfire-induced losses of big sagebrush are outpacing natural recovery and leading to substantial losses in habitat for species such as...

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Biological Soil Crusts in Ecological Restoration: Emerging Research and Perspectives

In this introductory paper for a special issue of the journal Restoration Ecology focused on the restoration of biological soil crusts, authors...

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Weed-Suppressive Bacteria Did Not Control Bromus tectorum

Recent trials using a bacterial bioherbicide known as D7 have had mixed results in controlling invasive annual grasses in rangelands. 

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Components and Predictors of Biocrusts

Although biological soil crusts occur globally in arid and semi-arid environments, the occurrence of biocrusts has not previously been related to...

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Passive Restoration of Vegetation and Biocrusts

Livestock exclosures established in response to the 1934 Taylor Grazing Act offer a chance to quantify reference conditions for biological soil crusts...

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Two Promising Tackifiers may Enhance Moss Growth for Biocrust Restoration

Establishing mosses could be valuable in restoring biological soil crusts following disturbance, yet a good method for delivering and establishing...

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Why Sagebrush Re-establishment After Fire is so Difficult

Big sagebrush ecosystems are particularly sensitive to wildfires and life history information on big sagebrush is scarce and vital for restoration...

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Effects of Disturbance on Vascular Plants and Biocrusts in Sagebrush Steppe

Semi-arid sagebrush ecosystems experience chronic disturbances through grazing, invasive grasses, and acute disturbance of fire. Biocrusts, a...

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Protocol for Describing Indicators of Rangeland Health

Assessing rangeland health is useful from a land management perspective in providing a baseline or early indicator of degradation and for prioritizing...

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Sagebrush Steppe Resilience and the Interaction of Climate and Management

Invasive grass species are a threat to many ecosystems around the world and in sagebrush habitats of the western United States, presence of non-native...

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Science and Products

*Disclaimer: Listing outside positions with professional scientific organizations on this Staff Profile are for informational purposes only and do not constitute an endorsement of those professional scientific organizations or their activities by the USGS, Department of the Interior, or U.S. Government