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
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.
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.
Available nitrogen: A time-based study of manipulated resource islands
Monitoring temporal change in riparian vegetation of Great Basin National Park
Plant invaders, global change and landscape restoration
Integrated monitoring of hydrogeomorphic, vegetative, and edaphic conditions in riparian ecosystems of Great Basin National Park, Nevada
Science for the changing Great Basin
Effects of invasive alien plants on fire regimes
Interactions of cattle grazing and climate change- hierarchical data analysis
New proposed national resources inventory protocols on nonfederal rangelands
Transitions in rangeland evaluations: A review of the major transitions in rangeland evaluations during the last 25 years and speculation about future evaluations
Restoring forbs for sage grouse habitat: Fire, microsites, and establishment methods
The effect of stochiastic technique on estimates of population viability from transition matrix models
Rangeland health attributes and indicators for qualitative assessment
Non-USGS Publications**
**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.
Science and Products
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- Data
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.
- Multimedia
- Publications
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: 112Available nitrogen: A time-based study of manipulated resource islands
Spatial and temporal heterogeneity of available nitrogen are critical determinants of the distribution and abundance of plants and animals in ecosystems. Evidence for the resource island theory suggests that soils below tree and shrub canopies contain higher amounts of resources, including available nitrogen, than are present in interspace areas. Disturbances, such as prescribed fire and tree remoAuthorsMichelle M. Stubbs, David A. PykeMonitoring temporal change in riparian vegetation of Great Basin National Park
Disturbance in riparian areas of semiarid ecosystems involves complex interactions of pulsed hydrologic flows, herbivory, fire, climatic effects, and anthropogenic influences. We resampled riparian vegetation within ten 10-m × 100-m plots that were initially sampled in 1992 in 4 watersheds of the Snake Range, east central Nevada. Our finding of significantly lower coverage of grasses, forbs, and sAuthorsErik A. Beever, David A. Pyke, Jeanne C. Chambers, Fred Landau, S.D. SmithPlant invaders, global change and landscape restoration
Modifications in land uses, technology, transportation and biogeochemical cycles currently influence the spread of organisms by reducing the barriers that once restricted their movements. We provide an overview of the spatial and temporal extent for agents of environmental change (land and disturbance transformations, biogeochemical modifications, biotic additions and losses) and highlight those tAuthorsD.A. Pyke, S.T. KnickIntegrated monitoring of hydrogeomorphic, vegetative, and edaphic conditions in riparian ecosystems of Great Basin National Park, Nevada
In semiarid regions such as the Great Basin, riparian areas function as oases of cooler and more stable microclimates, greater relative humidity, greater structural complexity, and a steady flow of water and nutrients relative to upland areas. These qualities make riparian areaʼs attractive not only to resident and migratory wildlife, but also to visitors in recreation areas such as Great Basin NaAuthorsErik A. Beever, D.A. PykeScience for the changing Great Basin
The U.S. Geological Survey (USGS), with its multidisciplinary structure and role as a federal science organization, is well suited to provide integrated science in the Great Basin of the western United States. A research strategy developed by the USGS and collaborating partners addresses critical management issues in the basin, including invasive species, status and trends of wildlife populationsAuthorsErik Beever, David A. PykeEffects of invasive alien plants on fire regimes
Plant invasions are widely recognized as significant threats to biodiversity conservation worldwide. One way invasions can affect native ecosystems is by changing fuel properties, which can in turn affect fire behavior and, ultimately, alter fire regime characteristics such as frequency, intensity, extent, type, and seasonality of fire. If the regime changes subsequently promote the dominance of tAuthorsM.L. Brooks, C. M. D'Antonio, D.M. Richardson, J.M. DiTomaso, J.B. Grace, R.J. Hobbs, J. E. Keeley, M. Pellant, D. PykeInteractions of cattle grazing and climate change- hierarchical data analysis
No abstract available.AuthorsD. Clausnitzer, Manuela M. P. Huso, David A. Pyke, Jayne Belnap, T. B. Graham, R. L. Sanford, S. L. PhillipsNew proposed national resources inventory protocols on nonfederal rangelands
No abstract available.AuthorsK.E. Spaeth, F.B. Pierson, J. E. Herrick, P. Shaver, David A. Pyke, Mike Pellant, D. Thompson, B. DaytonTransitions in rangeland evaluations: A review of the major transitions in rangeland evaluations during the last 25 years and speculation about future evaluations
No abstract available.AuthorsDavid A. Pyke, Jeffrey E. HerrickRestoring forbs for sage grouse habitat: Fire, microsites, and establishment methods
The decline and range reduction of sage grouse populations are primarily due to permanent loss and degradation of sagebrush–grassland habitat. Several studies have shown that sage grouse productivity may be limited by the availability of certain preferred highly nutritious forb species that have also declined within sagebrush ecosystems of the Intermountain West, U.S.A. The purpose of this study wAuthorsTroy A. Wirth, David A. PykeThe effect of stochiastic technique on estimates of population viability from transition matrix models
Population viability analysis is an important tool for conservation biologists, and matrix models that incorporate stochasticity are commonly used for this purpose. However, stochastic simulations may require assumptions about the distribution of matrix parameters, and modelers often select a statistical distribution that seems reasonable without sufficient data to test its fit. We used data fromAuthorsT.N. Kaye, David A. PykeRangeland health attributes and indicators for qualitative assessment
Panels of experts from the Society for Range Management and the National Research Council proposed that status of rangeland ecosystems could be ascertained by evaluating an ecological site's potential to conserve soil resources and by a series of indicators for ecosystem processes and site stability. Using these recommendations as a starting point, we developed a rapid, qualitative method for asseAuthorsDavid A. Pyke, Jeffrey E. Herrick, Patrick Shaver, Mike PellantNon-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.
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*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