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Synopsis: Remotely sensed data and GIS were used to compare the effects of clear-cutting and road-building on the landscape pattern of the Bighorn National Forest, Wyoming. Landscape patterns were quantified for each of 12 watersheds on a series of four maps that differed only in the degree of clear-cutting and road density. Researchers analyzed several landscape pattern metrics for the landscape as a whole and for the lodgepole pine and spruce/fir cover classes across the four maps to determine the relative effects of clear-cutting and road building on the pattern of each watershed. At both the landscape and cover class scales, clear-cutting and road building resulted in increased fragmentation as represented...
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Synopsis: Researchers measured the effects of grassland amount and fragmentation on upland and wetland songbird and duck densities and nest success across 16 landscapes in southern Alberta. By comparing these landscape-level effects with local-scale responses, including distance to various edges and vegetation characteristics, the study demonstrated that few species were in fact influenced by grassland amount or fragmentation. In contrast, distance to edge and local vegetation characteristics had significant effects on densities and nest success of many species. Landscape level effects were much less apparent when local characteristics were included in the models. Therefore, researchers concluded that local habitat...
Synopsis: This paper aimed to quantify the relative importance of habitat area and configuration, as well as the contrast in resistance between habitat and non-habitat, on genetic differentiation patterns. Using spatially explicit, individual-based simulation modeling, researchers found that habitat configuration had stronger relationships with genetic differentiation than did habitat area. The pattern of habitat in a landscape will affect the distribution of the population and the degree of connectivity across it, resulting in differential patterns of gene flow. Researchers also evaluated the predictive ability of six widely used landscape metrics and found that patch cohesion and correlation length of habitat...
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This map represents a potential Conservation Target (CT) for PFLCC's 'Pine Flatwoods and Dry Prairie' (PFDP) Priority Resource (PR). The potential CT is Landscape Configuration. . This layer was created for an initial investigation of potential CT's suggested at brainstorming workshops. The initial investigation entails locating available datasets to address the suggested CT as closely as possible and performing minimal analyses to determine their usefulness. The final set of CT's and their associated datasets will be chosen after targets (e.g., endpoints) are established as a threshold for achieving a conservation success for that CT. The available data layer to address landscape configuration is CLIP 4.0 core...
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This map represents a potential Conservation Target (CT) for PFLCC's 'Pine Flatwoods and Dry Prairie' (PFDP) Priority Resource (PR). The potential CT is Landscape Configuration. . This layer was created for an initial investigation of potential CT's suggested at brainstorming workshops. The initial investigation entails locating available datasets to address the suggested CT as closely as possible and performing minimal analyses to determine their usefulness. The final set of CT's and their associated datasets will be chosen after targets (e.g., endpoints) are established as a threshold for achieving a conservation success for that CT. The available data layer to address landscape configuration is CLIP 4.0 core...
Conclusions: Assessments of metapopulation structure must consider landscape pattern, but also the non-linear responses of organisms to such patterns Thresholds/Learnings: Synopsis: This study used beetles to empirically test the reliability of neutral percolation models to predict critical thresholds of landscape connectivity. Beetle movements declined sharply when grass cover dropped below 20% of the experimental plot. The findings of this study differed from what was predicted by the model, indicating that landscape connectivity is not dependent on spatial pattern alone, but is also highly dependent how individual organisms move within and among patches depending on the amount of cover. The results suggest that...
Synopsis: This study aimed to independently examine the effects of varying amounts and configurations of habitat at a landscape scale, with particular attention to critical persistence thresholds. A discrete reaction-diffusion model was used to estimate long-term equilibrium population persistence of a hypothetical species in a patchy landscape. When examined over a broad range of habitat amount and arrangements, population size was largely determined by the proportion of habitat (amount) in a landscape. However, when habitat coverage dropped below 30-50%, population response deviated, coinciding with a persistence threshold. Species persistence declined rapidly at this threshold range (50% for low degrees of aggregation,...
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Conclusions: Nest predators with different home-range sizes and habitat affinities responded to landscape configuration in different ways. Influence of landscape structure varied across scale. Thresholds/Learnings: Herbaceous cover was negatively associated with predation in roadsides whereas the proximity of woody cover was positively associated with predation rates. Synopsis: This study evaluated the influence of habitat structure and spatial configuration on nest predation in central Iowa. In a multi-scale analysis of 10 artificial ground nests along 136 roadsides across six watersheds, researchers found that predation was affected by the surrounding landscape mosaic. Nest predators with different home-range...
Conclusions: Structurally complex landscapes support more species than simple landscapes, implying that habitat patches in complex landscapes receive a higher diversity of potential colonists from the overall species pool than do patches of the same size and quality in less complex landscapes. Thresholds/Learnings: Synopsis: Structurally complex landscapes support more species than simple landscapes, implying that habitat patches in complex landscapes receive a higher diversity of potential colonists from the overall species pool than do patches of the same size and quality in less complex landscapes. Movement across habitats is a common phenomenon in many species and the spillover of organisms from natural habitats...
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Synopsis: This study attempts to build a forest fragmentation database for the conterminous United States by utilizing high-resolution NLCD data, roads, and a series of fragmentation indices that quantify forest landscape patterns. The paper outlines a methodology for assessing forest fragmentation and provides a comprehensive data set to be used as a base for further investigation at smaller scales. Conclusions: A forest fragmentation database for the conterminous United States was built to quantify forest landscape patterns nationwide. The paper outlines a methodology for assessing forest fragmentation and provides a comprehensive data set to be used as a base for further investigation at smaller scales. Thresholds/Learnings:...
Synopsis: This study tested the null hypothesis that densities of mammalian populations are constant over patches of varied size. In other words, performance as estimated by density does not covary with patch area. Researchers used a composite database from published studies and found that densities of 20 out of 32 species did not vary with patch area. Five species showed increasing density-area relationships and seven species showed decreasing density-area relationships. Landscapes comprised of smaller, less isolated patched tended to have negative density-area relationships and landscapes with large, more isolated patched tended to have positive density-area relationships. These results indicate that there are...
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Synopsis: This study investigated the magnitude of change in landscape structure resulting from road and logging since the onset of timber harvesting in 1950. Overall, roads were found to have had a greater impact on landscape structure than logging. A three-fold increase in road density between 1950 and 1993 accounted for most of the changes in landscape configuration including mean patch size, edge density, and core area. Change in landscape structure varied as a function of landscape extent. At a large scale of 228,000 ha, change in landscape change over time was trivial, suggesting that the landscape is capable of incorporating disturbances with minimal impact. At intermediate scales of 1000-10,000 ha, change...
Conclusions:Bird and medium sized mammal population densities were affected by the arrangement and density of exurban housing developments, with both species groups avoiding developments up to 180 away. The composition of native wildlife is altered in the vicinity of exurban housing developments.Thresholds/Learnings:Avian densities were altered up to 180m away from homes on the perimeter of ex-urban developments.
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Synopsis: Large-scale patterns of land use and fragmentation have been associated with the decline of many imperiled wildlife populations. Lesser prairie-chickens (Tympanuchus pallidicinctus) are restricted to the southern Great Plains of North America, and their population and range have declined by > 90% over the past 100 years. Our objective was to examine scale-dependent relationships between landscape structure and change and long-term population trends for lesser prairie-chicken populations in the southern Great Plains. We used a geographic information system (GIS) to quantify landscape composition, pattern and change at multiple scales (extents) for fragmented agricultural landscapes surrounding 10 lesser...
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Synopsis: Resource managers confronted with preserving ecosystems for prairie wetland birds in fragmented landscapes require landscape studies that direct conservation efforts over broad geographic regions. We investigated the role of local and landscape factors affecting habitat suitability by integrating remotely sensed wetland and land-cover data with wetland bird habitat models. We linked habitat models with locations of easement and fee-title wetlands to evaluate spatial location and extent of protected, suitable habitat. We also simulated impacts of the loss of small wetlands on suitability of larger wetlands for mobile species that use multiple wetlands. Lastly, we evaluated the efficacy of waterfowl habitat...
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Conclusions: The proportion of wetlands in the watershed at different scales affects dissolved organic carbon (DOC) concentrations in downstream lakes and rivers. Thresholds/Learnings: Synopsis: This study quantifies how the proportion of wetlands in the watershed at different scales affects dissolved organic carbon (DOC) concentrations in downstream lakes and rivers. Whether the watershed influence varies with season or hydrologic type of lake was also examined. The scaling and modelling approach used offered a useful way to examine heterogeneity of land cover types within the watershed and spatial arrangements, while allowing generality of conclusions with a large sample size. Zones of increasing distance from...


    map background search result map search result map Landscape indictors of human impacts to riverine systems Forest fragmentation of the coterminous United States: assessing forest intactness through road density and spatial characteristics. Effects of landscape structure on nest predation on roadsides of a mid-western agroecosystem: a multi-scale analysis. Comparative evaluation of experimental approaches to the study of habitat fragmentation effects Watershed analysis of forest fragmentation by clearcuts and roads in a Wyoming forest A landscape approach to conserving wetland bird habitat in the prairie pothole region of eastern South Dakota. Multi-scale effects of habitat loss and fragmentation on lesser prairie-chicken populations in the US souther Great Plains. A multi-scale analysis of avian response to habitat amount and fragmentation in the Canadian dry mixed-grass prairie. PFDP Configuration PFDP Configuration Multi-scale effects of habitat loss and fragmentation on lesser prairie-chicken populations in the US souther Great Plains. A multi-scale analysis of avian response to habitat amount and fragmentation in the Canadian dry mixed-grass prairie. A landscape approach to conserving wetland bird habitat in the prairie pothole region of eastern South Dakota. Effects of landscape structure on nest predation on roadsides of a mid-western agroecosystem: a multi-scale analysis. Watershed analysis of forest fragmentation by clearcuts and roads in a Wyoming forest Comparative evaluation of experimental approaches to the study of habitat fragmentation effects PFDP Configuration PFDP Configuration Forest fragmentation of the coterminous United States: assessing forest intactness through road density and spatial characteristics. Landscape indictors of human impacts to riverine systems