Results
526 - 550 of 1229 Items << < 17 18 19 20 21 22 23 24 25 26 > >>
526 - 550 of 1229 Items << < 17 18 19 20 21 22 23 24 25 26 > >>
|
To predict how species establish and disperse within novel communities, the spatial scale at which competition, predation, and habitat interact must be understood. We explored how these factors affect the distribution and abundance of the exotic...
2003-12-01
|
|
Plankton samples for this present study were collected from an
area off the southern Oregon coast, extending westward to about 83
kilometers offshore. Over this sampling area, 41 species of adult
copepods were identified, including representatives...
1970-11-30 (iso8601)
|
|
We, the U.S. Fish and Wildlife Service (Service), announce the opening of a public comment period on the proposed and final designation of critical habitat for the Klamath River and Columbia River populations of bull trout [Salvelinus...
2005-05-25
2008-08-18 2005-06-22 |
|
The Pacific Northwest has a relatively low diversity of primary freshwater fishes
with most of the endemism and diversity in the Columbia River and Klamath River.
However, the Oregon Coastal Subprovince defined as the coastal rivers from Miami...
2008-12-19 (iso8601)
|
|
Human-induced fragmentation of forests is increasing, yet the consequences of these landscape changes to vertebrate communities are poorly understood. Despite progress in our understanding of how bird communities
respond to forest fragmentation...
1993-08-05 (iso8601)
|
|
By acting as novel competitors and predators, a single invasive species can detrimentally affect multiple native species in different trophic levels. Although quantifying invasive effects through single-species interactions is important,...
2017-03-10
|
|
Disturbance and microclimate interact to play a central role influencing the composition and structure of plant communities. In this thesis, I examined plant community composition and structure twenty years after high severity wildfires with and...
2007-11-19 (iso8601)
|
|
Questions of assemblage persistence, resiliency arid continuity in time were investigated with data from seasonal bottom trawl surveys conducted by the Northeast Fisheries Center, Woods Hole,
Massachusetts, from 1963-1978. Cluster analysis proved...
1982-10-26 (iso8601)
|
|
Field, greenhouse, growth chamber and laboratory experiments
evaluated factors affecting establishment, survival and production
of birdsfoot trefoil (Lotus corniculatus L.) and alfalfa (Medicago
sativa L.)
Field studies investigated the effects of...
1964-02-10 (iso8601)
|
|
Low intertidal communities of Oregon and Panama have many predator
and herbivore species. This diversity of consumers is important to the
organization of both communities because of qualitative differences
among the consumer species in their...
1982-09-28 (iso8601)
|
|
A systematic study was made of the species comprising
Phacelia section Miltitzia. These species, which are commonly
found in the Great Basin physiographic province of western North
America, are distinguished from other members of Phacelia by...
1979-10-18 (iso8601)
|
|
Few landscapes are immune to invasion by exotic plant species. The forested landscape in the western Cascade Range of Oregon appears to have some barriers to invasion, but the extensive road network provides a corridor and habitat for a suite of...
1997-06-27 (iso8601)
|
|
Two studies on Catherine Creek and Meadow Creek of the Upper Grande Ronde
River basin, quantified several physical and biotic influences on woody riparian community
composition and structure. The Catherine Creek study examined the association of...
1998-06-10 (iso8601)
|
|
The Wetland Reserve Program (WRP) is one conservation tool that mitigates national wetland loss and a primary goal for the program includes optimizing wildlife habitat by restoring wetland functions and values. Few studies have evaluated the WRP,...
2010-11-22 (iso8601)
|
|
Zooplankton were collected from adjacent littoral and limnetic sites in Lake Mead, Nevada-Arizona, USA. Limnetic species dominated both littoral and limnetic zooplankton communities; littoral species rarely exceeded 2% of monthly total zooplankton...
1991-01-01
|
|
Monitoring wildlife habitats has become important to forest ecosystem
management because it provides valuable information about the response of forests
and their species to harvest practices, impacts from recreational use, conservation
efforts,...
2000-02-15 (iso8601)
|
|
Demersal fishes were sampled at seven stations located inshore of Heceta Bank, on Oregon's continental
shelf, over a 2-yr period with a 3-m beam trawl designed to catch small fiatfishes. Two general
assemblages of fishes were recognized: a shallow...
1978 (iso8601)
|
|
The spatial distribution of plankton is highly aggregated, so one might expect that a vertically migrating animal enters a biotic environment that is markedly different each evening and that the changes in environment between daylight periods...
1970 (iso8601)
|
|
Most reserves fail to capture the habitat heterogeneity necessary to maintain viable
populations of wide-ranging species. Methods to determine defensible dimensions of
reserves and reserve networks are needed. The primary goal of this study was to...
2004-06-09 (iso8601)
|
|
The Jack Metcalf Papers document two
decades of Metcalf’s political career as a Washington State Senator and as
Representative for Washington State’s 2nd Congressional District. Collection
materials comprise a small amount of records...
|
|
Population dynamics of coral reef fishes and spiny lobster appear to be determined by variable recruitment interacting with post-settlement processes, particularly predation. The risk of predation may be modified by the scaling between prey and...
1997-04-10 (iso8601)
|
