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Conclusions: In response to logging, songbirds demonstrated “habitat compensation” by moving into different adjacent habitats across a fragmented landscape. Thresholds/Learnings: Synopsis: This study investigates the degree to which species respond differently to logging across different scales in Alberta’s boreal mixed-wood forests. Researchers tracked changes in the composition and abundance of songbirds at the patch-level and landscape level, finding significant variation between the two spatial scales. The results suggest that predictions of organism response based on the island biogeographic model are limited, and that—while responses varied across species—songbirds demonstrated “habitat compensation” by moving...
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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...
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...
Conclusions:Results indicate that breeding bird species richness patterns significantly increased with fragment size. Area-sensitive species required patches of suitable habitat at least 5-55 ha in size. Edge and vegetation-restricted species were more affected by overall habitat loss of habitat than reductions in average patch size.Thresholds/Learnings:Area-sensitive species required patches of suitable habitat at least 5-55 ha in size, and regularly avoided smaller grassland fragments even when they were composed of suitable habitat
Conclusions:Higher percentages of forest cover within the watershed and within a 30m buffer were related to healthy fish communities and water quality, while near stream grasslands and urban land cover in the watershed contributed negatively to the health of fish communities and water quality.Thresholds/Learnings:High percentages of forest cover within a 30m riparian buffer were related to healthy fish communities and water quality. Fish density increased with increase in the average length of riparian vegetation without gaps (>30m).
Conclusions:Unsuitable habitat surrounding a patch of suitable habitat creates islands of high species density from which successful dispersion becomes difficult. Therefore, habitat surrounding a patch, rather than the quality of the patch itself, may be a more important determining factor of species abundance.Thresholds/Learnings:
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:
Conclusions:Random camping and off-highway vehicles have impacted water quality in the Ghost-Waiparous basin of Alberta. Sediment loading coefficients in the lower regions of the Waiparous and Ghost rivers were much greater than would be expected in rivers draining a similar forested environment in the upper foothills of southern Alberta and were even greater than loading coefficients in streams draining agricultural lands at lower elevations where sediment erosion is a common problem.Thresholds/Learnings:
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Conclusions: Soil texture, native prairie and grassland cover, and proximity to linear disturbances affect habitat suitability for burrowing owls. Native prairie coverage was considered the most critical variable in determining the most suitable habitat. The higher the percentage of native prairie, the more suitable it is for burrowing owl habitat.*Note that this study generated landscape level models with coarse variables, and the thresholds and values used may not be directly applicable to other areas or for site-specific analysis. Thresholds/Learnings: Synopsis: This report provides information on the habitat suitability requirements of the burrowing owl. Due to limited available data, the model that this...
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Conclusions: Presents environmental indicators for the purpose of guiding future planning efforts. These include 16 key indicators incorporating 64 separate measures highlighting the status and trends in environmental issues, as well targets to guide planning efforts. Thresholds/Learnings: Road density thresholds: Grizzly Bear 0.4km/km2; Black Bear 1.25km/km2; Elk 0.62 km/km2; and Bull Trout 0.1-1.31 km/km2 Synopsis: This document represents British Columbia’s third environmental indicators report, including 16 key indicators incorporating 64 separate measures highlighting the status and trends in environmental issues. The information is grouped into six theme areas: biodiversity, water, stewardship, human health...
Synopsis: This foundational text focuses on the distribution patterns of landscape elements that affect flows of animals, plants, energy, mineral nutrients and water in an ecosystem. The book also discusses the ecological implications of landscape change over time. The book introduces the important and well documented concepts of patches, corridors, and a background matrix and the building blocks of landscape (figure 4). The patch-corridor-matrix model is thus comprised of these three principle components which, together, constitute a landscape mosaic: Patches are “relatively homogenous non-linear areas that differ from their surroundings”. Corridors are “strips of a particular patch type that differ from the adjacent...
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Conclusions: Seismic cutline proportion did not explain landscape use by grizzly bears, but secondary effects of cutlines on landscape structure did. Declining use was mainly associated with increasing proportions of closed forest, and increasing variation of inter-patch distances, while use was mainly increasing with increasing mean patch size. Thresholds/Learnings: Bears appear to use areas more when landscape patches tend to be larger, and mean patch size is generally reduced with additional seismic cutlines. Also, bears appear to use areas more when landscape patches are consistently spaced, and the spacing between landscape patches becomes more variable with additional seismic cutlines. Synopsis: This study...
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Conclusions: Increasing seismic line density from 0 to 8 km/km2 resulted in a 38% decline and an 82% decline in bird abundance when individuals used lines as territory boundaries or avoided edges by 50 m, respectively. When tested with ovenbirds, male ovenbirds showed a distinct use of one side of the seismic line, suggesting lines acted as territory boundaries. Ovenbirds declined with seismic line density when a threshold seismic line density of 8.5 km/km2 was reached. Above the threshold, Ovenbirds declined 19% for each 1 km/km2 increase in seismic line density. Thresholds/Learnings: Synopsis: In the boreal plains of Alberta, Canada, energy sector exploration has resulted in extensive dissection of the landscape...
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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...
Synopsis: This book is the foundational text for understanding landscape ecology in terms of pattern/process relationships. Forman introduces the concept of “indispensible patterns” of habitat and habitat linkages that, if protected, can conserve the majority of important ecological function in a landscape. While all or specific attributes of an ecosystem may not be protected by these measures, the most important assets will retain their integrity if the essential general patterns are maintained. Forman’s Indispensable Landscape Patterns are related to both configuration and connectivity and fragmentation (figure 1). Forman suggests that the following patterns are indispensable in maintaining an ecologically viable...
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Synopsis: Species status assessments are often hindered by a paucity of demographic, abundance, or distributional data. Although extinction-risk correlates have been identified, their wide applicability may be compromised by differences in the variables examined, modeling technique, and phylogenetic or distributional scale. Here, we apply a common analytical approach to examine 14 possible extinction-risk correlates for mammals, fishes, and birds throughout Canada. Among mammals, risk is positively and strongly correlated with road density and age at maturity for land animals and weakly with body size for sea dwellers. Delayed maturity is of primary importance to predicting risk status in fishes, with small body...
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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...
map background search result map search result map Environmental Trends in British Columbia 2002 Fragments are not islands: patch vs landscape perspectives on songbird presence and abundance in a harvested boreal forest. Modeling and field-testing of Ovenbird (Seiurus aurocapillus) responses to boreal forest dissection by energy sector development at multiple spatial scales. Seismic cutlines, changing landscape metrics, and grizzly bear landscape use in Alberta Comparative evaluation of experimental approaches to the study of habitat fragmentation effects 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. Correlates of Vertebrate Extinction Risk in Canada. Burrowing Owl Fragments are not islands: patch vs landscape perspectives on songbird presence and abundance in a harvested boreal forest. Seismic cutlines, changing landscape metrics, and grizzly bear landscape use in Alberta Multi-scale effects of habitat loss and fragmentation on lesser prairie-chicken populations in the US souther Great Plains. A landscape approach to conserving wetland bird habitat in the prairie pothole region of eastern South Dakota. Comparative evaluation of experimental approaches to the study of habitat fragmentation effects Modeling and field-testing of Ovenbird (Seiurus aurocapillus) responses to boreal forest dissection by energy sector development at multiple spatial scales. Environmental Trends in British Columbia 2002 Correlates of Vertebrate Extinction Risk in Canada.