SEARCH · USGS Science
Results for “Ecology”
Search indexed USGS publications on groundwater, aquifers, geologic maps, mineral resources and earthquakes. Explore source records by subject and place.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Deer in Arizona and New Mexico: their ecology and a theory explaining recent population decreases
No abstract available.
Effect of sediment transport and flow regulation on the ecology of gravel-bed rivers
No abstract available.
Discussion of: 'Ecological implications of river regulation of the United Kingdom' by R. W. Edwards and D. T. Crisp
No abstract available.
Results of a workshop concerning ecological zonation in bottomland hardwoods
Under Section 404 of the Clean Water Act, the U.S. Environmental Protection Agency (EPA) has regulatory responsibilities concerning the discharge of dredged or fill material into the Nation's waters. In addition to its advisory role in the U.S. Army Corps of Engineers' permit program, EPA has a number of specific authorities, including formulation of the Section 404(b)(1) Guidelines, use of Section 404(c) to prohibit disposal at particular sites, and enforcement actions for unauthorized discharges. A number of recent court cases focus on the geographic scope of Section 404 jurisdiction in potential bottomland hardwood (BLH) wetlands and the nature of landclearing activities in these areas that require a permit under Section 404. Accordingly, EPA needs to establish the scientific basis for implementing its responsibilities under Section 404 in bottomland hardwoods. EPA is approaching this task through a series of workshops designed to provide current scientific information on bottomland hardwoods and to organize that information in a manner pertinent to key questions, including the following. What are the characteristics of bottomland hardwoods (in terms of hydrology, soils, vegetation, fish, wildlife, agricultural potential, and the like) and how can the functions (e.g., flood storage, water quality maintenance, detrital export) that they perform best be quantified? How do perturbations like landclearing, levee construction, and drainage impact the functions that bottomland hardwoods perform and how can these effects best be quantified? And finally, how significant are the impacts and how is their significance likely to change under various management scenarios? The first workshop in this series was held December 3-7, 1984, in St. Francisville, Louisiana. The workshop was attended by over 40 scientists and regulators (see ACKNOWLEDGMENTS section) and facilitated by the editors of this report under an Interagency Agreement between EPA and the U.S. Fish and Wildlife Service. The general objective of the workshop was to examine ways in which the structure and function of BLH ecosystems can be characterized and, in particular, to investigate the utility of a conceptual framework developed at a workshop held in Lake Lanier, Georgia, in 1980. In this framework, the transition from aquatic habitats to upland habitats through a BLH ecosystem is divided into six zones based on concomitant variation in the soil moisture regime and associated vegetation (Table 1). The zonation concept is of particular interest to EPA from at least two perspectives. The first is simply as a framework for organizing information. If the zones are discernible in the field, have recognizable characteristics, and perform identifiable functions, they might form a useful basis for tasks such as assessing the impacts of a particular site-specific activity. The second is the potential utility of the zonation concept in identifying the wetland portions of BLH communities. If the zones can be recognized in the field, and if one or more of them can be shown consistently to have wetland characteristics (i.e., perform functions, such as detrital export, often attributed to wetlands), while others do not, then the zones might have utility in identifying areas that fall under the jurisdiction of Section 404. The workshop itself was divided into two parts. The first was a series of papers in which authors described current research and data-synthesis activities in the context of the zonation concept. The second was a series of six workgroups in which participants discussed the zonation concept from the perspective of hydrology, soils, vegetation, fish, wildlife, and ecosystem processes. This report is a compilation of the written material from those workgroups, much of which was produced at the workshop. The formal papers presented in the first part of the workshop have been distributed to participants under separate cover, but are referenced in this report by citations such as: (Jones, workshop presentation).
An ecological problem-solving process for managing special-interest species
We present a structured problem-solving process that can help resolve wildlife management issues. Management goals for wildlife species are expressed in terms of populations to be attained and maintained. Habitat quantity and quality necessary to achieve those population goals can then be determined. Proposed land-use changes are evaluated in terms of how they will contribute toward recovery of extinction of the species of interest.
Ecologic atlas of benthic foraminifera of the Gulf of Mexico
Explore the source record for details and available documents.
Human activities and ecological processes in bottomland hardwood ecosystems: the report of the Ecosystem Workgroup
No abstract available.
Ecology of wetlands in Big Meadows, Rocky Mountain National Park, Colorado
No abstract available.
Selected development needs for assessing ecological risk at the community and ecosystem level
No abstract available.
Ecological characteristics of fish assemblages in two seasonally inundated palustrine wetlands
No abstract available.
Ecology of wildfire, wildlife, and snowfall in Glacier National Park, Montana
No abstract available.
Characterizing multitemporal alpine snowmelt patterns for ecological inferences
No abstract available.
Book review of The little green bird: ecology of the willow flycatcher by Robert A. McCabe
No abstract available.