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Human activities have caused the decline of numerous species and ecosystems. To promote ecosystem resilience, recent management efforts aim to maintain ecosystem patterns and processes within their historical range of variability. There has been substantial concern that quaking aspen, the most widely distributed tree in North America and the most important deciduous tree in the subalpine forests of the Rocky Mountains, has declined significantly in the western landscape during the 20th century. This reported decline has been attributed to conifer encroachment associated with fire exclusion, as well as other causes. To assess long-term changes in the extent of quaking aspen in a 175000-ha study area in western Colorado,...
Determining occurrence and distribution is an essential 1st step in conservation planning for rare species. Spatial habitat models can be used to increase efficiency of field surveys and to improve understanding about factors influencing animal distributions. We used a modeling approach to identify and prioritize potential habitat for survey efforts for an uncommon mammal, the pygmy rabbit (Brachylagus idahoensis), for which detailed habitat data are limited. A base map of potential habitat in Idaho was defined using vegetation type and soil depth data. Documented locations (n = 164) were used to evaluate additional habitat variables to prioritize the potential habitat for surveys. We conducted field surveys to...
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The project incorporates Heiltsuk Traditional Knowledge and Values into ecosystem-based management planning within Strategic Landscape Reserve Design (SLRD) Landscape Units. The SLRD process seeks to identify areas to set aside from logging (harvesting) over short and long term timeframes. Heiltsuk Traditional Use Studies (HTUS) identify harvesting and other types of cultural sites that are important to Heiltsuk well-being. HTUS data that were incorporated into a Geographic GIS was drawn on for this project, where Heiltsuk members collected spatial and photographic data so that culturally important sites and forest resources could be buffered from forestry and other development activities. The base-line study, Map...
The Modular Modeling System (MMS) is an integrated system of computer software that is being developed to provide the research and operational framework needed to support development, testing, and evaluation of physical-process algorithms, and to facilitate integration of user-selected sets of algorithms into operational physical-process models. MMS uses a module library that contains compatible modules for simulating a variety of water, energy, and biogeochemical processes. A model is created by selectively linking modules from the library using MMS model-building tools. A geographic information system (GIS) interface also is being developed for MMS to support a variety of GIS tools for use in characterizing and...
The Gunnison River drains a mountainous basin in western Colorado, and is a large contributor of water to the Colorado River. As part of a study to assess water resource sensitivity to alterations in climate in the Gunnison River basin, climatic and hydrologic processes are being modeled. A geographic information system (GIS) is being used in this study as a link between data and modelers - serving as a common data base for project personnel with differing specialties, providing a means to investigate the effects of scale on model results, and providing a framework for the transfer of parameter values among models. Specific applications presented include: (1) developing elevation grids for a precipitation model...
Studies to identify gaps in the protection of habitat for species of concern have been inconclusive and ham- pered by single-scale or poor multi-scale sampling methods, large minimum mapping units (MMU?s of 2 ha to 100 ha), limited and subjectively selected field observations, and poor mathematical and ecological models. We overcome these obstacles with improved multi-scale sampling techniques, smaller MMU?s (< 0.02 ha), an unbiased sampling design based on double sampling, improved mathematical models including species-area curves corrected for habitat heterogeneity, and geographic information system-based ecological models. We apply this landscape analysis approach to address resource issues in Rocky Mountain...
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This data release contains the analytical results and evaluated source data files of geospatial analyses for identifying areas in Alaska that may be prospective for different types of lode gold deposits, including orogenic, reduced-intrusion-related, epithermal, and gold-bearing porphyry. The spatial analysis is based on queries of statewide source datasets of aeromagnetic surveys, Alaska Geochemical Database (AGDB3), Alaska Resource Data File (ARDF), and Alaska Geologic Map (SIM3340) within areas defined by 12-digit HUCs (subwatersheds) from the National Watershed Boundary dataset. The packages of files available for download are: 1. LodeGold_Results_gdb.zip - The analytical results in geodatabase polygon feature...
Land-cover mapping efforts within the USGS Gap Analysis Program have traditionally been state-centered; each state having the responsibility of implementing a project design for the geographic area within their state boundaries. The Southwest Regional Gap Analysis Project (SWReGAP) was the first formal GAP project designed at a regional, multi-state scale. The project area comprises the southwestern states of Arizona, Colorado, Nevada, New Mexico, and Utah. The land-cover map/dataset was generated using regionally consistent geospatial data (Landsat ETM+ imagery (1999–2001) and DEM derivatives), similar field data collection protocols, a standardized land-cover legend, and a common modeling approach (decision...
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Aim The recent concern that quaking aspen (Populus tremuloides Michx.) has been declining in parts of western North America due to fire suppression is largely based on trends during the latter part of the 20th century. The aim of the current study was to compare the extent of aspen in the modern landscape with its extent in the late 19th century prior to fire suppression, and to assess the effects of elevation, late-19th century fires, and pre-fire forest composition on the successional status of aspen. Location North-west Colorado, USA. Methods We used a georeferenced 1898 map and modern maps to examine trends in aspen dominance since the late 19th century in a 348,586 ha area of White River and Routt National...
Land managers need better techniques to assess exotic plant invasions. We used the cross-correlation statistic, IYZ, to test for the presence of spatial cross-correlation between pair- wise combinations of soil characteristics, topographic variables, plant species richness, and cover of vascular plants in a 754 ha study site in Rocky Mountain National Park, Colorado, U.S.A. Us- ing 25 large plots (1000 m2) in five vegetation types, 8 of 12 variables showed significant spatial cross-correlation with at least one other variable, while 6 of 12 variables showed significant spatial auto-correlation. Elevation and slope showed significant spatial cross-correlation with all variables except percent cover of native and...
    map background search result map search result map Influences of infrequent fire, elevation and pre-fire vegetation on the persistence of quaking aspen (Populus tremuloides Michx.) in the Flat Tops area, Colorado, USA Implementing Ecosystem-based Management in the Central Coast of British Columbia: Support for Heiltsuk Participation in the Strategic Landscape Reserve Design Process - NPLCC Final Report Influences of infrequent fire, elevation and pre-fire vegetation on the persistence of quaking aspen (Populus tremuloides Michx.) in the Flat Tops area, Colorado, USA Implementing Ecosystem-based Management in the Central Coast of British Columbia: Support for Heiltsuk Participation in the Strategic Landscape Reserve Design Process - NPLCC Final Report