Terrestrial Rates and Amplitudes of Changes in Ecoclimate Systems (TRACES) Completed
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.
Major- and trace-element characterization, expanded distribution, and a new chronology for the latest Pleistocene Glacier Peak tephras in western North America
A quarter-million years of paleoenvironmental change at Bear Lake, Utah and Idaho
Paleomagnetism and environmental magnetism of GLAD800 sediment cores from Bear Lake, Utah and Idaho
Climatic and limnologic setting of Bear Lake, Utah and Idaho
Endogenic carbonate sedimentation in Bear Lake, Utah and Idaho, over the last two glacial-interglacial cycles
Mineralogic Causes of Variations in Magnetic Susceptibility of Late Pleistocene and Holocene Sediment from Great Salt Lake, Utah
Geochemical evidence for hydroclimatic variability over the last 2460 years from Crevice Lake in Yellowstone National Park, USA
Quantitative estimation of bioclimatic parameters from presence/absence vegetation data in North America by the modern analog technique
A 2650-year-long record of environmental change from northern Yellowstone National Park based on a comparison of multiple proxy data
Influence of the diversion of Bear River into Bear Lake (Utah and Idaho) on the environment of deposition of carbonate minerals
Atlas of relations between climatic parameters and distributions of important trees and shrubs in North America: Ecoregions of North America
Chronology of the last glacial maximum in the upper Bear River Basin, Utah
- 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: 39Major- and trace-element characterization, expanded distribution, and a new chronology for the latest Pleistocene Glacier Peak tephras in western North America
The Glacier Peak tephra beds are among the most widespread and arguably some of the most important late Pleistocene chronostratigraphic markers in western North America. These beds represent a series of closely-spaced Plinian and sub-Plinian eruptions from Glacier Peak, Washington. The two most widespread beds, Glacier Peak 'G' and 'B', are reliably distinguished by their glass major and trace eleAuthorsS.C. Kuehn, D.G. Froese, P. E. Carrara, F.F. Foit, N.J.G. Pearce, P. RotheislerA quarter-million years of paleoenvironmental change at Bear Lake, Utah and Idaho
A continuous, 120-m-long core (BL00-1) from Bear Lake, Utah and Idaho, contains evidence of hydrologic and environmental change over the last two glacial-interglacial cycles. The core was taken at 41.95??N, 111.31??W, near the depocenter of the 60-m-deep, spring-fed, alkaline lake, where carbonate-bearing sediment has accumulated continuously. Chronological control is poor but indicates an averageAuthorsD. S. Kaufman, Jordon Bright, W.E. Dean, J. G. Rosenbaum, K. Moser, R. Scott Anderson, Steven M. Colman, C.W. Heil, Gonzalo Jiménez-Moreno, M. C. Reheis, K. R. SimmonsPaleomagnetism and environmental magnetism of GLAD800 sediment cores from Bear Lake, Utah and Idaho
A ???220,000-year record recovered in a 120-m-long sediment core from Bear Lake, Utah and Idaho, provides an opportunity to reconstruct climate change in the Great Basin and compare it with global climate records. Paleomagnetic data exhibit a geomagnetic feature that possibly occurred during the Laschamp excursion (ca. 40 ka). Although the feature does not exhibit excursional behavior (???40?? depAuthorsC.W. Heil, J.W. King, J. G. Rosenbaum, R. L. Reynolds, Steven M. ColmanClimatic and limnologic setting of Bear Lake, Utah and Idaho
Bear Lake is a large alkaline lake on a high plateau on the Utah-Idaho border. The Bear River was partly diverted into the lake in the early twentieth century so that Bear Lake could serve as a reservoir to supply water for hydropower and irrigation downstream, which continues today. The northern Rocky Mountain region is within the belt of the strongest of the westerly winds that transport moisturAuthorsW.E. Dean, W.A. Wurtsbaugh, V.A. LamarraEndogenic carbonate sedimentation in Bear Lake, Utah and Idaho, over the last two glacial-interglacial cycles
Sediments deposited over the past 220,000 years in Bear Lake, Utah and Idaho, are predominantly calcareous silty clay, with calcite as the dominant carbonate mineral. The abundance of siliciclastic sediment indicates that the Bear River usually was connected to Bear Lake. However, three marl intervals containing more than 50% CaCO3 were deposited during the Holocene and the last two interglacial iAuthorsW.E. DeanMineralogic Causes of Variations in Magnetic Susceptibility of Late Pleistocene and Holocene Sediment from Great Salt Lake, Utah
We describe here results of magnetic susceptibility (MS) measurements and magnetic mineralogy of sediments sampled in three cores from the south basin of Great Salt Lake. The cores were obtained in 1996 with a Kullenburg-type piston corer at sites in close proximity: core 96-4 at 41 deg 01.00' N, 112 deg 28.00' W and cores 96-5 and 96-6 at 41 deg 00.09' N, 112 deg 23.05' W. Cores 96-5 (2.16 m longAuthorsRichard L. Reynolds, Joseph G. Rosenbaum, Robert S. ThompsonGeochemical 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. DeanQuantitative estimation of bioclimatic parameters from presence/absence vegetation data in North America by the modern analog technique
The method of modern analogs is widely used to obtain estimates of past climatic conditions from paleobiological assemblages, and despite its frequent use, this method involved so-far untested assumptions. We applied four analog approaches to a continental-scale set of bioclimatic and plant-distribution presence/absence data for North America to assess how well this method works under near-optimalAuthorsR.S. Thompson, K. H. Anderson, P. J. BartleinA 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. PowerInfluence of the diversion of Bear River into Bear Lake (Utah and Idaho) on the environment of deposition of carbonate minerals
Bear River, the largest river in the Great Basin, had some of its flow diverted into Bear Lake through a series of canals constructed between 1911 and 1918, turning Bear Lake into a reservoir. The prediversion lake had an unusually high Mg2+ : Ca2+ ratio (38 by weight), which resulted in precipitation of CaCO3 as aragonite. The amount and mineralogy of the carbonate did not change immediately afteAuthorsW.E. Dean, R. M. Forester, Jordon Bright, R.Y. AndersonAtlas of relations between climatic parameters and distributions of important trees and shrubs in North America: Ecoregions of North America
Climate is the primary factor controlling the continental-scale distribution of plant species, although the relations between climatic parameters and species' ranges are only now beginning to be quantified. This volume examines the relations between climate and the distributions of (1) Kuchler's 'potential natural vegetation' categories for the 48 contiguous States of the United States of America,AuthorsRobert S. Thompson, Katherine H. Anderson, Richard T. Pelltier, Sarah L. Shafer, Patrick J. BartleinChronology of the last glacial maximum in the upper Bear River Basin, Utah
The headwaters of the Bear River drainage were occupied during the Last Glacial Maximum (LGM) by outlet glaciers of the Western Uinta Ice Field, an extensive ice mass (???685 km2) that covered the western slope of the Uinta Mountains. A well-preserved sequence of latero-frontal moraines in the drainage indicates that outlet glaciers advanced beyond the mountain front and coalesced on the piedmont.AuthorsB.J.C. Laabs, Jeffrey S. Munroe, J. G. Rosenbaum, K.A. Refsnider, D.M. Mickelson, B. S. Singer, M.W. Caffee