Greg Pederson
Biography
Education
Ph.D. Watershed Management & Ecohydrology. 2010. University of Arizona, School of Natural Resources.
M.S. Environmental Science. 2004. Montana State University
B.S. Ecology and Evolution in Botany & Zoology. 2000. Michigan State University
Research Interests
Greg Pederson is a research scientist working primarily on the role of climate variability in driving changes in water resources, and other biological and physical components of mountainous ecosystems in western North America. Of particular interest is the magnitude of low-frequency hydroclimatic variability and its implications for drought risk, as well as the climatic drivers associated with observed changes in mountain snowpack, streamflow, glaciers, and forest disturbance events. Understanding the time intervals and spatial scales over which these processes operate requires a long-term perspective, and for that I rely on proxy records primarily from tree-ring and lake sediments along with instrumental and modeled climate records. Recent and ongoing studies have addressed the susceptibility of natural resources to climate variability and change, and sought to apply both the modern and paleoclimatic records to present day resource management problems. Greg is affiliate faculty with the Earth Sciences department and the Institute on Ecosystems (IoE) at Montana State University. He grew up in Michigan and earned his B.S. in Ecology and Botany from Michigan State University, before moving to Montana to earn a M.S. from Montana State University. In 2010 he completed his Ph.D in watershed management and ecohydrology at the University of Arizona then returned to Bozeman Montana.
Current Research Projects Include:
- Drivers of Drought in the Upper Colorado River Basin [DOI Southwestern CSC]
- Multi-century perspectives on current and future streamflow in the Missouri River Basin [NSF P2C2]
- Reconstructions of Columbia River flow from winter and summer precipitation sensitive proxies in the Northwestern U.S. with implications for 21st century flow [CSC and CLU]
- A Broader view of North American climate over the past two millennia: Synthesizing paleoclimate records from diverse archives [USGS Powell Center]
- Holocene climate variability in Alaska from relict wood [DOI Alaska CSC]
- Holocene climates of the Northern Rockies from relict wood emerging from ice patches [CLU]
- Megadroughts and uncertainty in Upper Colorado River flow low-frequency variability [CLU]
Science and Products
Reconstructing Ancient Human and Ecosystem Responses to Holocene Climate Conditions
This research project will reconstruct Holocene climatic conditions to better understand human adaptation and response to past environmental variability.
Multi-century perspectives on current and future streamflow in the Missouri River Basin
The Missouri River system is the life-blood of the American Midwest providing water resources that drive agriculture, industry, hydroelectric power generation, and ecosystems. However, the Missouri River Basin (MRB) (Figure 1) is the only major river in the western U.S. for which hydrologic reconstructions from tree rings have not been generated in any systematic way. This knowledge gap is...
Drivers of Drought in the Upper Colorado River Basin
The purpose of this project is to investigate Colorado River basin droughts, and the role of temperature in influencing runoff efficiency. The project uses paleoclimatic data to extend instrumental climate and flow records, along with projected warming to assess the range of possible conditions that may be expected to occur and to determine how warming temperatures may influence river flow and...
Greg Pederson's Past Projects
This work is interdisciplinary and would not be possible without the collaboration of colleagues and their respective institutions. Research funding over the years has been provided by 1) the U.S. Geological Survey's National Research Program (NRP), the Climate and Land Use Program (CLU), the Southwestern and Alaska Climate Science Center, the Western Mountain Initiative (WMI), and the...
Broader view of North American climate over the past two millennia: Synthesizing paleoclimate records from diverse archives
Regional- to continental-scale paleoclimate syntheses of temperature and hydroclimate in North America are essential for understanding long-term spatiotemporal variability in climate, and for properly assessing risk on decadal and longer timescales. However, existing syntheses rely almost exclusively on tree-ring records, which are known to underestimate low-frequency variability and rarely...
Science and Forecasting to Inform Implementation of the Greater Yellowstone Coordinating Committee’s Whitebark Pine Management Strategy
The goal of this project was to inform implementation of the Greater Yellowstone Coordinating Committee (GYCC) Whitebark Pine (WBP) subcommittee’s “WBP Strategy” based on climate science and ecological forecasting. Project objectives were to: 1. Forecast ecosystem processes and WBP habitat suitability across the Greater Yellowstone Area (GYA) under alternative IPCC future scenarios; 2. Improve...
Integrating Climate and Biological Data into Management Decisions for the Greater Sage-Grouse and their Habitats
Climate affects both the demographics of the Greater sage-grouse bird and the condition and long-term viability of their habitats, including sage-steppe communities. This project builds on collaboration among federal land managers, state wildlife biologists, scientists, and other organizations to create a long-term framework for implementing adaptive management for the sage-grouse. The study...
Increased drought severity tracks warming in the United States’ largest river basin
Across the Upper Missouri River Basin, the recent drought of 2000 to 2010, known as the “turn-of-the-century drought,” was likely more severe than any in the instrumental record including the Dust Bowl drought. However, until now, adequate proxy records needed to better understand this event with regard to long-term variability have been lacking....
Martin, Justin; Pederson, Gregory T.; Woodhouse, Connie A.; Cook, Edward R.; McCabe, Gregory J.; Anchukaitis, Kevin J.; Wise, Erika K.; Erger, Patrick; Dolan, Larry S.; McGuire, Marketa; Gangopadhyay, Subhrendu; Chase, Katherine J.; Littell, Jeremy S.; Gray, Stephen; St. George, Scott; Friedman, Jonathan M.; Sauchyn, David J.; St. Jacques, Jeannine-Marie; King, John C. Dynamics, variability, and change in seasonal precipitation reconstructions for North America
Cool and warm season precipitation totals have been reconstructed on a gridded basis for North America using 439 tree-ring chronologies correlated with December-April totals and 547 different chronologies correlated with May-July totals. These discrete seasonal predictor chronologies are not significantly correlated with the alternate season and...
Stahle, David W.; Cook, Edward R; Burnette, Dorian J; Torbenson, Max C.A.; Howard, Ian M; Griffin, Daniel; Villanueva Diaz, Jose; Cook, Benjamin I.; Williams, Park A.; Watson, Emma; Sauchyn, David J.; Pederson, Neil; Woodhouse, Connie A.; Pederson, Gregory T.; Meko, David M.; Coulthard, Bethany; Crawford, Christopher J. Whitebark pine (Pinus albicaulis) growth and defense in response to mountain pine beetle outbreaks
Whitebark pine (Pinus albicaulis) is a critical forest species of Northern Rocky Mountain upper subalpine ecosystems, yet little is known about the physiological response of whitebark pine to disturbance (e.g. fire, bark beetles, and pathogens) across a range of diverse environmental gradients. Resin–based defenses have long been recognized as the...
Kichas, Nickolas E.; Hood, Sharon M.; Pederson, Gregory T.; Everett, Richard G.; McWethy, David B. 1200 years of Upper Missouri River streamflow reconstructed from tree rings
Paleohydrologic records can provide unique, long-term perspectives on streamflow variability and hydroclimate for use in water resource planning. Such long-term records can also play a key role in placing both present day events and projected future conditions into a broader context than that offered by instrumental observations. However,...
Martin, Justin; Pederson, Gregory T.; Woodhouse, Connie A.; Cook, Edward R; McCabe, Gregory J.; Wise, Erika K.; Erger, Patrick; Dolan, Larry; McGuire, Marketa; Gangopadhyay, Subhrendu; Chase, Katherine J.; Littell, Jeremy S.; Gray, Stephen; St. George, Scott; Friedman, Jonathan M.; Sauchyn, David J.; St. Jacques, Jannine; King, John W. Streamflow reconstruction in the Upper Missouri River Basin using a novel Bayesian network model
A Bayesian model that uses the spatial dependence induced by the river network topology, and the leading principal components of regional tree-ring chronologies for paleo-streamflow reconstruction is presented. In any river basin, a convergent, dendritic network of tributaries comes together to form the main stem of a river. Consequently, it is...
Ravindranath, Arun; Devineni, Naresh; Lall, Upmanu; Cook, Edward; Pederson, Gregory T.; Martin, Justin; Woodhouse, Connie A. An integrated framework for ecological drought across riverscapes of North America
Climate change is increasing the severity and extent of extreme droughts events, posing a critical threat to freshwater ecosystems, particularly with increasing human demands for diminishing water supplies. Despite the importance of drought as a significant driver of ecological and evolutionary dynamics, current understanding of drought...
Kovach, Ryan; Dunham, Jason B.; Al-Chokhachy, Robert; Snyder, Craig; Beever, Erik A.; Pederson, Gregory T.; Lynch, Abigail; Hitt, Nathaniel P.; Konrad, Christopher P.; Jaeger, Kristin; Rea, Alan H.; Sepulveda, Adam J.; Lambert, Patrick M.; Stoker, Jason M.; Giersch, J. Joseph; Muhlfeld, Clint C. Changing station coverage impacts temperature trends in the Upper Colorado River Basin
Over the Upper Colorado River Basin (UCRB), temperatures in widely used gridded data products do not warm as much as mean temperatures from a stable set of U.S. Historical Climatology Network (USHCN) stations, located at generally lower elevations, in most months of the year. This is contrary to expectations of elevation-dependent warming, which...
McAfee, Stephanie A.; McCabe, Gregory J.; Gray, Stephen; Pederson, Gregory T. Identifying major avalanche years from a regional tree-ring based avalanche chronology for the U.S. Northern Rocky Mountains
Avalanches not only pose a major hazard to people and infrastructure, but also act as an important ecological disturbance. In many mountainous regions in North America, including areas with existing transportation corridors, reliable and consistent avalanche records are sparse or non-existent. Thus, inferring long-term avalanche...
Peitzsch, Erich H.; Fagre, Daniel B.; Pederson, Gregory T.; Hendrikx, Jordy; Birkeland, Karl W.; Stahle, Daniel Placing the Common Era in a Holocene context: Millennial to centennial patterns and trends in the hydroclimate of North America over the past 2000 years
A synthesis of 93 hydrologic records from across North and Central America, and adjacent tropical and Arctic islands, reveals centennial to millennial trends in the regional hydroclimates of the Common Era (CE; past 2000 years). The hydrological records derive from materials stored in lakes, bogs, caves, and ice from extant glaciers, which have...
Shuman, Bryan; Routson, Cody C.; McKay, Nicholas P.; Fritz, Sherilyn; Kaufman, Darrell S.; Kirby, Matthew; Nolan, Connor; Pederson, Gregory T.; St. Jacques, Jeannine-Marie Hydroclimatology of the Missouri River basin
Despite the importance of the Missouri River for navigation, recreation, habitat, hydroelectric power, and agriculture, relatively little is known about the basic hydroclimatology of the Missouri River basin (MRB). This is of particular concern given the droughts and floods that have occurred over the past several decades and the potential future...
Wise, Erika K.; Woodhouse, Connie A.; McCabe, Gregory J.; Pederson, Gregory T.; St. Jacques, Jeannine-Marie Investigating runoff efficiency in upper Colorado River streamflow over past centuries
With increasing concerns about the impact of warming temperatures on water resources, more attention is being paid to the relationship between runoff and precipitation, or runoff efficiency. Temperature is a key influence on Colorado River runoff efficiency, and warming temperatures are projected to reduce runoff efficiency. Here, we investigate...
Woodhouse, Connie A.; Pederson, Gregory T. Application of synthetic scenarios to address water resource concerns: A management-guided case study from the Upper Colorado River Basin
Water managers are increasingly interested in better understanding and planning for projected resource impacts from climate change. In this management-guided study, we use a very large suite of synthetic climate scenarios in a statistical modeling framework to simultaneously evaluate how (1) average temperature and precipitation changes, (2)...
McAfee, Stephanie A.; Pederson, Gregory T.; Woodhouse, Connie A.; McCabe, Gregory J.