Publications
Filter Total Items: 1433
A new map of global ecological land units — An ecophysiographic stratification approach A new map of global ecological land units — An ecophysiographic stratification approach
In response to the need and an intergovernmental commission for a high resolution and data-derived global ecosystem map, land surface elements of global ecological pattern were characterized in an ecophysiographic stratification of the planet. The stratification produced 3,923 terrestrial ecological land units (ELUs) at a base resolution of 250 meters. The ELUs were derived from data on...
Authors
Roger Sayre, Jack Dangermond, Charlie Frye, Randy Vaughan, Peter Aniello, Sean P. Breyer, Douglas Cribbs, Dabney Hopkins, Richard Nauman, William Derrenbacher, Dawn J. Wright, Clint Brown, Charles Convis, Jonathan H. Smith, Laurence Benson, D. Paco VanSistine, Harumi Warner, Jill Janene Cress, Jeffrey J. Danielson, Sharon L. Hamann, Thomas Cecere, Ashwan D. Reddy, Devon Burton, Andrea Grosse, Diane TRUE, Marc Metzger, Jens Hartmann, Nils Moosdorf, Hans Durr, Marc Paganini, Pierre Defourny, Olivier Arino, Simone Maynard, Mark Anderson, Patrick Comer
Geomorphic evidence for enhanced Pliocene-Quaternary faulting in the northwestern Basin and Range Geomorphic evidence for enhanced Pliocene-Quaternary faulting in the northwestern Basin and Range
Mountains in the U.S. Basin and Range Province are similar in form, yet they have different histories of deformation and uplift. Unfortunately, chronicling fault slip with techniques like thermochronology and geodetics can still leave sizable, yet potentially important gaps at Pliocene–Quaternary (∼105–106 yr) time scales. Here, we combine existing geochronology with new geomorphic...
Authors
Magdalena A Ellis, Barnes Jason B, Joseph P. Colgan
By
Geology, Energy, and Minerals Mission Area, Energy Resources Program, Mineral Resources Program, National Laboratories Program, Science and Decisions Center, Groundwater and Streamflow Information Program, Geology, Minerals, Energy, and Geophysics Science Center, Geosciences and Environmental Change Science Center
U-Pb zircon geochronology of plutonism in the northern Peninsular Ranges batholith, southern California: Implications for the Late Cretaceous tectonic evolution of southern California U-Pb zircon geochronology of plutonism in the northern Peninsular Ranges batholith, southern California: Implications for the Late Cretaceous tectonic evolution of southern California
Utilizing both sensitive high-resolution ion microprobe (SHRIMP) and conventional isotope dilution–thermal ionization mass spectrometry (ID-TIMS) methods, crystallization and/or emplacement ages have been obtained for a suite of Cretaceous intermediate-composition plutonic samples collected along a roughly E-W–trending traverse through the northern Peninsular Ranges batholith. Previously...
Authors
Wayne R. Premo, Douglas M. Morton, Joseph L. Wooden, C. Mark Fanning
Applying threshold concepts to conservation management of dryland ecosystems: Case studies on the Colorado Plateau Applying threshold concepts to conservation management of dryland ecosystems: Case studies on the Colorado Plateau
Ecosystems may occupy functionally distinct alternative states, some of which are more or less desirable from a management standpoint. Transitions from state to state are usually associated with a particular trigger or sequence of triggers, such as the addition or subtraction of a disturbance. Transitions are often not linear, rather it is common to see an abrupt transition come about...
Authors
Matthew A. Bowker, Mark E. Miller, Steven L. Garman, Travis Belote
Pb-Sr-Nd-O isotopic characterization of Mesozoic rocks throughout the northern end of the Peninsular Ranges batholith: Isotopic evidence for the magmatic evolution of oceanic arc–continental margin accretion during the Late Cretaceous of southern Californ Pb-Sr-Nd-O isotopic characterization of Mesozoic rocks throughout the northern end of the Peninsular Ranges batholith: Isotopic evidence for the magmatic evolution of oceanic arc–continental margin accretion during the Late Cretaceous of southern Californ
Within the duration of the U.S. Geological Survey (USGS)–based Southern California Areal Mapping Project (SCAMP), many samples from the northern Peninsular Ranges batholith were studied for their whole-rock radioisotopic systematics (rubidium-strontium [Rb-Sr], uranium-thorium-lead [U-Th-Pb], and samarium-neodymium [Sm-Nd]), as well as oxygen (O), a stable isotope. The results of three...
Authors
Ronald W. Kistler, Joseph L. Wooden, Wayne R. Premo, Douglas M. Morton
The changing southwest The changing southwest
This chapter describes important geographical and socio-economic characteristics and trends in the Southwest—such as population and economic growth and changes in land ownership, land use, and land cover—that provide the context for how climate change will likely affect the Southwest. The chapter also describes key laws and institutions relevant to adaptive management of resources.
Authors
David M. Theobald, William Travis, Mark A. Drummond, Eric Gordon, Michelle Betsill
Digital-image processing and image analysis of glacier ice Digital-image processing and image analysis of glacier ice
This document provides a methodology for extracting grain statistics from 8-bit color and grayscale images of thin sections of glacier ice—a subset of physical properties measurements typically performed on ice cores. This type of analysis is most commonly used to characterize the evolution of ice-crystal size, shape, and intercrystalline spatial relations within a large body of ice...
Authors
Joan J. Fitzpatrick
Wyoming Basin Rapid Ecoregional Assessment: Work Plan Wyoming Basin Rapid Ecoregional Assessment: Work Plan
The overall goal of the Rapid Ecoregional Assessments (REAs) being conducted for the Bureau of Land Management (BLM) is to provide information that supports regional planning and analysis for the management of ecological resources. The REA provides an assessment of baseline ecological conditions, an evaluation of current risks from drivers of ecosystem change, and a predictive capacity...
Authors
Natasha B. Carr, Steven L. Garman, Annika Walters, Andrea Ray, Cynthia P. Melcher, Jeff S. Wesner, Michael S. O’Donnell, Kirk R. Sherrill, Nils C. Babel, Zachary H. Bowen
Loess origin, transport, and deposition over the past 10,000 years, Wrangell-St. Elias National Park, Alaska Loess origin, transport, and deposition over the past 10,000 years, Wrangell-St. Elias National Park, Alaska
Contemporary glaciogenic dust has not received much attention, because most research has been on glaciogenic dust of the last glacial period or non-glaciogenic dust of the present interglacial period. Nevertheless, dust from modern glaciogenic sources may be important for Fe inputs to primary producers in the ocean. Adjacent to the subarctic Pacific Ocean, we studied a loess section near...
Authors
Daniel R. Muhs, James R. Budahn, John P. McGeehin, E. Arthur Bettis, Gary L. Skipp, James B. Paces, Elisabeth A. Wheeler
Geochronology and paleoenvironment of pluvial Harper Lake, Mojave Desert, California, USA Geochronology and paleoenvironment of pluvial Harper Lake, Mojave Desert, California, USA
Accurate reconstruction of the paleo-Mojave River and pluvial lake (Harper, Manix, Cronese, and Mojave) system of southern California is critical to understanding paleoclimate and the North American polar jet stream position over the last 500 ka. Previous studies inferred a polar jet stream south of 35°N at 18 ka and at ~ 40°N at 17–14 ka. Highstand sediments of Harper Lake, the upstream...
Authors
Anna L. Garcia, Jeffrey R. Knott, Shannon Mahan, Jordan Bright
Land-use and land-cover change in three corn belt ecoregions: Similarities and differences Land-use and land-cover change in three corn belt ecoregions: Similarities and differences
Land use categorical changes, though not as numerous as one might suspect, vary by type within the three designated ecozones of the Corn Belt with the westernmost zone showing the most temporary change vis-a-vis the more permanent changes taking place in the eastern and central zones.
Authors
Roger F. Auch, Chris R. Laingen, Mark A. Drummond, Kristi Sayler, Ryan R. Reker, Michelle A. Bouchard, Jeffrey J. Danielson
Forest ecosystems: Vegetation, disturbance, and economics Forest ecosystems: Vegetation, disturbance, and economics
Forests cover about 47% of the Northwest (NW–Washington, Oregon, and Idaho) (Smith et al. 2009, fig. 5.1, table 5.1). The impacts of current and future climate change on NW forest ecosystems are a product of the sensitivities of ecosystem processes to climate and the degree to which humans depend on and interact with those systems. Forest ecosystem structure and function, particularly in
Authors
Jeremy S. Littell, Jeffrey A. Hicke, Sarah L. Shafer, Susan M. Capalbo, Laurie L. Houston, Patty Glick