Vegetation changes caused by climatic variations and/or land use may have large impacts on forests, agriculture, rangelands, natural ecosystems, and endangered species. Climate modeling studies indicate that vegetation cover, in turn, has a strong influence on regional climates, and this must be better understood before models can estimate future environmental conditions. To address these issues, this project investigates vegetational response to climatic change, and vegetation-land surface impacts on climate change. The project involves calibration of the modern relations between the range limits of plant species and climatic variables, relations that are then used: 1) to estimate past climatic fluctuations from paleobotanical data for a number of time periods within the late Quaternary; 2) to 'validate' climate model simulations of past climates; 3) to explore the potential influences of land cover changes on climate change; and 4) to estimate the potential future ranges of plant species under a number of future climate scenarios. Project methodologies and data are also part of the national global change assessment of potential impacts of future climate changes.
Develop techniques and data sets to elucidate the modern relations among plant species distributions and climatic parameters in North America.
We developed a 25-km equal-area grid for modern climate for North America and compared the distributions of approximately 400 important plant species with these data (USGS Prof. Paper 1650). We also developed an analogue-based method of estimating past climate from these data and paleobotanical assemblages. This effort continues as we add additional species to the data set and as we devise new methods of portraying and transmitting the results to the scientific community.
Estimate past climatic conditions from paleobotanical data, based on the modern climate-vegetation relations identified using the methods described above.
We have worked with the NOAA paleoclimatology program and the University of Colorado to establish a packrat midden database and to augment the North American Pollen Database with pollen data from western North America. We have also taken a leading role in an international effort to document changes in biomes through the late Quaternary in North America. From these efforts we are preparing synoptic-scale reconstructions and regional lapse rate reconstructions for (initially) the Last Glacial Maximum at 21ka and the mid-Holocene at 6 ka. We will compare the results of different approaches to reconstructing climate based on both species-level and biome-level data, as well as implementing methods being developed by European colleagues.
Explore numerical model simulations of past climates by comparing simulated and observed past plant distributions.
The ability of climate models to simulate climates different from that of the present-day can be evaluated by comparing features of simulated past climates with geological data. We are using the relations identified from modeling using the gridded data described above to simulate the past ranges of selected plant species (based on numerical climate model simulations) for key past time intervals and will compare these with observed paleobotanical data. The results provide insights into both the direction and amplitude of errors in the model climate simulations, and are critical for modeling future climatic conditions.
Investigate the impacts of vegetation and other land-cover changes on climate.
Over the past 15 years climate modelers have become increasingly aware that changes in the land surface (as well as in the ocean) can strongly influence the direction and amplitude of climate changes. Project members will be develop landscape reconstructions for North America for (initially) the Last Glacial Maximum and 6 ka. These reconstructions will be used as boundary conditions for a series of numerical model simulations that will iteratively explore the role of land surface and ocean feedbacks in climate change.
Estimate potential changes in the distributions of plant species and biomes under a range of future climate scenarios.
Our initial approach was to use the modern climate/land surface relations with a selected numerical climate model simulation of a 2xCO2 climate to explore the potential impacts of future climate change on vegetation and hydrology in the western United States (USGS Circular 1153). As part of the national assessment of impacts of climate change, we are expanding this approach to include a range of simulations by different climate modeling groups, as well as to use information from the BIOME6000 effort to incorporate the effects of higher levels of atmospheric carbon dioxide on plant physiology and water utilization.
Below are publications associated with this project.
Atlas of relations between climatic parameters and distributions of important trees and shrubs in North America: Revisions for all taxa from the United States and Canada and new taxa from the western United States
Atlas of relations between climatic parameters and distributions of important trees and shrubs in North America—Modern data for climatic estimation from vegetation inventories
Introduction to paleoenvironments of Bear Lake, Utah and Idaho, and its catchment
Enhanced Late Holocene ENSO/PDO expression along the margins of the eastern North Pacific
Holocene record of precipitation seasonality from lake calcite δ18O in the central Rocky Mountains, United States
A 2650-year-long record of environmental change from northern Yellowstone National Park based on a comparison of multiple proxy data
Geochemical evidence for hydroclimatic variability over the last 2460 years from Crevice Lake in Yellowstone National Park, USA
A Composite Depth Scale for Sediments from Crevice Lake, Montana
Tree-ring dated landslide movements and seismic events in southwestern Montana, USA
Late Quaternary sedimentary features of Bear Lake, Utah and Idaho
Allogenic sedimentary components of Bear Lake, Utah and Idaho
Sedimentary constraints on late Quaternary lake-level fluctuations at Bear Lake, Utah and Idaho
- Overview
Vegetation changes caused by climatic variations and/or land use may have large impacts on forests, agriculture, rangelands, natural ecosystems, and endangered species. Climate modeling studies indicate that vegetation cover, in turn, has a strong influence on regional climates, and this must be better understood before models can estimate future environmental conditions. To address these issues, this project investigates vegetational response to climatic change, and vegetation-land surface impacts on climate change. The project involves calibration of the modern relations between the range limits of plant species and climatic variables, relations that are then used: 1) to estimate past climatic fluctuations from paleobotanical data for a number of time periods within the late Quaternary; 2) to 'validate' climate model simulations of past climates; 3) to explore the potential influences of land cover changes on climate change; and 4) to estimate the potential future ranges of plant species under a number of future climate scenarios. Project methodologies and data are also part of the national global change assessment of potential impacts of future climate changes.
Develop techniques and data sets to elucidate the modern relations among plant species distributions and climatic parameters in North America.
We developed a 25-km equal-area grid for modern climate for North America and compared the distributions of approximately 400 important plant species with these data (USGS Prof. Paper 1650). We also developed an analogue-based method of estimating past climate from these data and paleobotanical assemblages. This effort continues as we add additional species to the data set and as we devise new methods of portraying and transmitting the results to the scientific community.
Estimate past climatic conditions from paleobotanical data, based on the modern climate-vegetation relations identified using the methods described above.
We have worked with the NOAA paleoclimatology program and the University of Colorado to establish a packrat midden database and to augment the North American Pollen Database with pollen data from western North America. We have also taken a leading role in an international effort to document changes in biomes through the late Quaternary in North America. From these efforts we are preparing synoptic-scale reconstructions and regional lapse rate reconstructions for (initially) the Last Glacial Maximum at 21ka and the mid-Holocene at 6 ka. We will compare the results of different approaches to reconstructing climate based on both species-level and biome-level data, as well as implementing methods being developed by European colleagues.
Explore numerical model simulations of past climates by comparing simulated and observed past plant distributions.
The ability of climate models to simulate climates different from that of the present-day can be evaluated by comparing features of simulated past climates with geological data. We are using the relations identified from modeling using the gridded data described above to simulate the past ranges of selected plant species (based on numerical climate model simulations) for key past time intervals and will compare these with observed paleobotanical data. The results provide insights into both the direction and amplitude of errors in the model climate simulations, and are critical for modeling future climatic conditions.
Investigate the impacts of vegetation and other land-cover changes on climate.
Over the past 15 years climate modelers have become increasingly aware that changes in the land surface (as well as in the ocean) can strongly influence the direction and amplitude of climate changes. Project members will be develop landscape reconstructions for North America for (initially) the Last Glacial Maximum and 6 ka. These reconstructions will be used as boundary conditions for a series of numerical model simulations that will iteratively explore the role of land surface and ocean feedbacks in climate change.
Estimate potential changes in the distributions of plant species and biomes under a range of future climate scenarios.
Our initial approach was to use the modern climate/land surface relations with a selected numerical climate model simulation of a 2xCO2 climate to explore the potential impacts of future climate change on vegetation and hydrology in the western United States (USGS Circular 1153). As part of the national assessment of impacts of climate change, we are expanding this approach to include a range of simulations by different climate modeling groups, as well as to use information from the BIOME6000 effort to incorporate the effects of higher levels of atmospheric carbon dioxide on plant physiology and water utilization.
- Publications
Below are publications associated with this project.
Filter Total Items: 39Atlas of relations between climatic parameters and distributions of important trees and shrubs in North America: Revisions for all taxa from the United States and Canada and new taxa from the western United States
This is the seventh volume in an atlas series that explores the relations between the geographic distributions of woody plant species and climatic variables in North America. A 25-kilometer (km) equal-area grid of modern climatic and bioclimatic variables was constructed from weather data. The geographic distributions of selected tree and shrub species were digitized, and the presence or absence oAuthorsRobert S. Thompson, Katherine H. Anderson, Richard T. Pelltier, Laura E. Strickland, Sarah L. Shafer, Patrick J. Bartlein, Andrew K. McFaddenAtlas of relations between climatic parameters and distributions of important trees and shrubs in North America—Modern data for climatic estimation from vegetation inventories
Vegetation inventories (plant taxa present in a vegetation assemblage at a given site) can be used to estimate climatic parameters based on the identification of the range of a given parameter where all taxa in an assemblage overlap ("Mutual Climatic Range"). For the reconstruction of past climates from fossil or subfossil plant assemblages, we assembled the data necessary for such analyses for 53AuthorsRobert S. Thompson, Katherine H. Anderson, Richard T. Pelltier, Laura E. Strickland, Sarah L. Shafer, Patrick J. BartleinIntroduction to paleoenvironments of Bear Lake, Utah and Idaho, and its catchment
In 1996 a group led by the late Kerry Kelts (University of Minnesota) and Robert Thompson (U.S. Geological Survey) acquired three piston cores (BL96-1, -2, and -3) from Bear Lake. The coring arose from their recognition of Bear Lake as a potential repository of long records of paleoenvironmental change. They recognized that the lake is located in an area that is sensitive to changes in regional clAuthorsJoseph G. Rosenbaum, Darrell S. KaufmanEnhanced Late Holocene ENSO/PDO expression along the margins of the eastern North Pacific
Pacific climate is known to have varied during the Holocene, but spatial patterns remain poorly defined. This paper compiles terrestrial and marine proxy data from sites along the northeastern Pacific margins and proposes that they indicate 1) suppressed ENSO conditions during the middle Holocene between ∼8000 and 4000 cal BP with a North Pacific that generally resembled a La Niña-like or more negAuthorsJohn A. Barron, Lesleigh AndersonHolocene record of precipitation seasonality from lake calcite δ18O in the central Rocky Mountains, United States
A context for recent hydroclimatic extremes and variability is provided by a ∼10 k.y. sediment carbonate oxygen isotope (δ18O) record at 5–100 yr resolution from Bison Lake, 3255 m above sea level, in northwestern Colorado (United States). Winter precipitation is the primary water source for the alpine headwater lake in the Upper Colorado River Basin and lake water δ18O measurements reflect seasonAuthorsLesleigh AndersonA 2650-year-long record of environmental change from northern Yellowstone National Park based on a comparison of multiple proxy data
Geochemical, stable-isotope, pollen, charcoal, and diatom records were analyzed at high-resolution in cores obtained from Crevice Lake, a varved-sediment lake in northern Yellowstone National Park. The objective was to reconstruct the ecohydrologic, vegetation, and fire history of the watershed for the last 2650 years to better understand past climate variations at the forest-steppe transition. ThAuthorsC. Whitlock, W. Dean, J. Rosenbaum, L. Stevens, S. Fritz, B. Bracht, M. PowerGeochemical evidence for hydroclimatic variability over the last 2460 years from Crevice Lake in Yellowstone National Park, USA
A 2460-year-long hydroclimatic record for Crevice Lake, Yellowstone National Park, Montana was constructed from the ??18O values of endogenic carbonates. The ??18O record is compared to the Palmer Hydrologic Drought Index (PHDI) and Pacific Decadal Oscillation (PDO) indices, as well as inferred discharge of the Yellowstone River. During the last century, high ??18O values coincide with drought conAuthorsL.R. Stevens, W.E. DeanA Composite Depth Scale for Sediments from Crevice Lake, Montana
As part of a study to derive records of past environmental change from lake sediments in the western United States, a set of cores was collected from Crevice Lake, Montana, in late February and early March 2001. Crevice Lake (latitude 45.000N, longitude 110.578W, elevation 1,713 meters) lies adjacent to the Yellowstone River at the north edge of Yellowstone National Park. The lake is more than 31AuthorsJ. G. Rosenbaum, G. Skipp, J. Honke, C. ChapmanTree-ring dated landslide movements and seismic events in southwestern Montana, USA
Because many tree species can live for several centuries or longer (Brown 1996), tree-ring analysis can be a valuable tool to date geomorphic events such as landslides, earthquakes, and avalanches in regions lacking long historical records. Typically, a catastrophic landslide will destroy all trees on the landslide, but trees on slower moving landslides may survive. For example, the Slumgullion eaAuthorsPaul E. Carrara, J. Michael O'NeillLate Quaternary sedimentary features of Bear Lake, Utah and Idaho
Bear Lake sediments were predominantly aragonite for most of the Holocene, reflecting a hydrologically closed lake fed by groundwater and small streams. During the late Pleistocene, the Bear River flowed into Bear Lake and the lake waters spilled back into the Bear River drainage. At that time, sediment deposition was dominated by siliciclastic sediment and calcite. Lake-level fluctuation during tAuthorsJ. P. SmootAllogenic sedimentary components of Bear Lake, Utah and Idaho
Bear Lake is a long-lived lake filling a tectonic depression between the Bear River Range to the west and the Bear River Plateau to the east, and straddling the border between Utah and Idaho. Mineralogy, elemental geochemistry, and magnetic properties provide information about variations in provenance of allogenic lithic material in last-glacial-age, quartz-rich sediment in Bear Lake. Grain-size dAuthorsJ. G. Rosenbaum, W.E. Dean, R. L. Reynolds, M. C. ReheisSedimentary constraints on late Quaternary lake-level fluctuations at Bear Lake, Utah and Idaho
A variety of sedimentological evidence was used to construct the lake-level history for Bear Lake, Utah and Idaho, for the past ???25,000 years. Shorelines provide evidence of precise lake levels, but they are infrequently preserved and are poorly dated. For cored sediment similar to that in the modern lake, grain-size distributions provide estimates of past lake depths. Sedimentary textures proviAuthorsJ. P. Smoot, J. G. Rosenbaum