Publications
Filter Total Items: 1333
Changes in vegetation and biological soil crust communities on sand dunes stabilizing after a century of grazing on San Miguel Island, Channel Island National Park, California
San Miguel Island is the westernmost of the California Channel Islands and one of the windiest areas on the west coast of North America. The majority of the island is covered by coastal sand dunes, which were stripped of vegetation and subsequently mobilized due to droughts and sheep ranching during the late 19th century and early 20th century. Since the removal of grazing animals, vegetation and
Authors
Kristine L. Zellman
Late quaternary paleoseismology of the west valley fault zone: Insights from the Baileys Lake trench site
No abstract available.
Authors
Michael D. Hylland, Christopher B. DuRoss, Greg N. McDonald, Susan S. Olig, Charles G. Oviatt, Shannon Mahan, Anthony J. Crone, Stephen F. Personius
Quantifying and valuing ecosystem services: An application of ARIES to the San Pedro River basin, USA
A large body of research exists that identifies and values ecosystem services - the benefits that ecosystems provide to humans (MA, 2005) - and their underlying ecological processes. However, the development of software decision support tools that integrate ecology, economics and geography that can be independently used within the public, private, academic and NGO sectors is a more recent phenomen
Authors
Kenneth J. Bagstad, Darius J. Semmens, Ferdinando Villa, Gary Johnson
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 observations an
Authors
Magdalena A Ellis, Barnes Jason B, Joseph Colgan
By
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
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
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 sampled by dee
Authors
Joan J. Fitzpatrick
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 for evaluat
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
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 Chitina,
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
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-most pluv
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 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
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 relativel
Authors
Jeremy S. Littell, Jeffrey A. Hicke, Sarah L. Shafer, Susan M. Capalbo, Laurie L. Houston, Patty Glick
Constraints on the age of the Great Sand Dunes, Colorado, from subsurface stratigraphy and OSL dates
The age of the Great Sand Dunes has been debated for nearly 150 yr. Seven ages ranging from Miocene to late Holocene have been proposed for them. This paper presents new information—chiefly subsurface stratigraphic data, OSL dates, and geomorphic evidence—that indicates that the Great Sand Dunes began to form in the latter part of the middle Pleistocene. The dunes overlie a thick wedge of piedmont
Authors
Richard F. Madole, Shannon Mahan, Joseph H. Romig, Jeremy C. Havens