Filters: Tags: Isolation (X)
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Small aspen stands are disappearing from the landscape in the Southwest, so it is important to understand their contribution to the avian community. We sampled birds in 53 small, isolated aspen stands and 53 paired plots within the ponderosa pine forest in northern Arizona, during the 1996 and 1997 breeding seasons. Bird species richness and abundance were higher in aspen than in pine. However, bird species richness and abundance did not vary with size of the aspen patch or isolation index. In addition, direct ordination of species distributions with habitat factors suggested no distinct avian communities. This suggests that aspen stands do not harbor separate populations, but rather are locations where the regional...
Categories: Publication;
Types: Citation,
Journal Citation;
Tags: Biological Conservation,
Pinus ponderosa,
Populus tremuloides,
area,
birds,
Conclusions: At small spatial scales, where extirpation risks are high, landscape fragmentation will likely have long-term negative consequences on the genetic variation of individual assemblages of coastal cutthroat trout. Thresholds/Learnings: Synopsis: This study aimed to determine if coastal cutthroat trout were genetically structured within streams and to assess the effects of habitat fragmentation on coastal cutthroat trout genetic variation. Habitat fragmented by roads and other human disturbances acted as dispersal barriers, which strongly influenced coastal cutthroat trout genetic structure, diversity, and differentiation. At range-wide spatial scales, fragmentation potentially contributes to coastal cutthroat...
Categories: Publication;
Types: Citation,
Map Service,
OGC WFS Layer,
OGC WMS Layer,
OGC WMS Service;
Tags: Coast Range,
Conservation Genetics,
Dispersal,
Headwater streams,
Isolation,
These data are CSV files comprised of a heading and tables from Appendix 1 and Appendix 2 in the accompanying paper. The tables show the sampling dates and locations for the coachwhip (Masticophis flagellum) and striped racer (Masticophis lateralis) in pit-fall arrays (Fisher et al. 2008) monitored in southern California from 1995-2000. GPS data are shown in decimal degrees and were collected in the field using the WGS84 datum system. Elevation is in meters. Columns in the tables include a site ID number assigned to each site name, the year and calendar dates each site was sampled, number of arrays, number of sampling days, number of sampling occasions, and whether or not each of the target species were detected...
Conclusions:Patch area was shown to be an important determinant of species richness irrespective of habitat heterogeneity. Isolation in space was also a significant factors in determining the degree of species richness in a grassland landscape.Thresholds/Learnings:
Categories: Publication;
Types: Citation;
Tags: Denmark,
Land use configuration,
Landscape fragmentation,
Natural cover amount,
Natural cover heterogeneity,
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