Skip to main content
Advanced Search

Filters: Types: Map Service (X) > Tags: {"scheme":"https://www.sciencebase.gov/vocab/category/Landscape%20Patterns%20Catalog/TaxaKeywords"} (X) > Extensions: Citation (X) > Types: OGC WFS Layer (X)

98 results (23ms)   

View Results as: JSON ATOM CSV
thumbnail
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:...
thumbnail
Synopsis: The effects of the 17,400 ha Cerro Grande fire patch in New Mexico on erosion and sedimentation processes were analyzed by this study, located in the Jemez Mountains upstream of the Los Alamos Reservoir, New Mexico. This study provides a unique data set demonstrating post-fire erosion rates relative to pre-fire conditions. The fire affected a large fraction of the watershed, with 32% of the basin experiencing a moderate to high severity burn, including some of the steepest mountainous portions of the basin. Average sediment deposition was 150 m3/year prior to the fire, equivalent to an average basin-wide denudation rate of 0.009 mm/year. The year after the fire, over 21,800 m3 of sediment accumulated in...
thumbnail
Conclusions: Marten capture rates were negatively correlated with increasing proximity of open areas and increasing extent of high-contrast edges. Forested landscapes were unsuitable for martens when the average nearest-neighbor distance between open, non-forested patches was <100m. Thresholds/Learnings: Synopsis: This study aimed to determine whether American marten abundance changed with incremental increases in habitat fragmentation caused by the combined effects of natural openings and timber clearcuts. Researchers evaluated differences in marten capture rates in 18 study sites with different levels of fragmentation. Martens appeared to respond negatively to low levels of habitat fragmentation, even with remaining...
thumbnail
Conclusions: Elk habitat selection ratios varied in response to road pattern. Regularly spaced roads negatively influenced habitat selection, whereas a clumped pattern supported larger blocks of road-free habitat. Road density threshold at which elk could still occur in high numbers: 1.5 km/km⊃2; Thresholds/Learnings: Road density threshold at which elk could still occur in high numbers: 1.5 km/km⊃2; Synopsis: This study tested 3 aspects of an elk road density model to determine patterns of elk behavior relative to road density and configuration. The study compared model predictions with observed values of elk habitat selection at varying levels of road density. It also compared the effect of different spatial...
thumbnail
Synopsis: This study examined the reluctance of different birds species to cross habitat gaps in a fragmented forest landscape. Researchers induced birds in the post-fledging period to cross gaps of varying widths and to choose between routes through woodland or across open areas by attracting them with recorded chickadee mobbing calls. Overall, birds were twice as likely to travel through 50 m of woodland than they were to travel through 50 m of open gap areas to reach the recording. When given a choice of traveling through woodland or across a gap, the majority of birds preferred woodland routes, even when they were three times longer than shortcuts in the open. Birds did not just use movement corridors, but strongly...
thumbnail
Synopsis: Agronomic intensification has transformed many agricultural landscapes into expansive monocultures with little natural habitat. A pervasive concern is that such landscape simplification results in an increase in insect pest pressure, and thus an increased need for insecticides. We tested this hypothesis across a range of cropping systems in the Midwestern United States, using remotely sensed land cover data, data from a national census of farm management practices, and data from a regional crop pest monitoring network. We found that, independent of several other factors, the proportion of harvested cropland treated with insecticides increased with the proportion and patch size of cropland and decreased...
thumbnail
Synopsis: Large scale natural disturbances from wildfire and severe insect infestations can significantly impact water quality downstream of forested headwaters. Forest fires impact water quality due to sediment input of the ash and soot and by chemical changes to surface and groundwater. This has recently been extensively studied in southwestern Alberta, after the “Lost Creek” wildfire of 2003. Four years of comprehensive hydrology and water quality data from seven watersheds were evaluated and synthesized to assess the implications of wildfire and post-fire intervention (salvage logging) on downstream drinking water treatment. Burned and unburned reference watersheds were examined by the authors. Far more contaminants...
thumbnail
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...
thumbnail
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...
thumbnail
Synopsis: The study examined the effects of road networks on suburbanizing ecosystems, using grassland bird distribution to explore the relative ecological importance of variables relative to linear disturbances and the effect of road traffic volumes. The study found that roads primarily affect ecological variables for 1) distance from road and 2) habitat patch size. The study also found that road traffic volumes are correlated to avian distribution, suggesting that traffic volumes have an ecological effect. The research suggests that traffic noise is the primary ecological effect of roads and that roads with higher traffic volumes extend the road effect zone outwards of 100 m and up to 1,200 m. Given the ecological...
thumbnail
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...
thumbnail
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...
thumbnail
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...
thumbnail
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...
thumbnail
The study examined the effects of forest harvest practices that approximate natural disturbance processes to evaluate whether these practices help conserve biodiversity. Past research has shown that management practices that mimic natural disturbance events such as forest fires is a successful habitat conservation strategy, particularly for boreal forest bird communities. The study investigated how bird communities differed between postharvest and postfire stands in the mid-boreal region of Alberta. The research found that the most significant difference between postfire and postharvest landscapes is the amount and orientation of residual live and dead trees. Postfire stands consist largely of standing dead trees...
thumbnail
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...
thumbnail
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...
thumbnail
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 The influence of forest fragmentation and landscape pattern on American martens. 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. Changes in bird communities in boreal mixedwood forest: harvest and wildfire effects over 30 years. Landscape indictors of human impacts to riverine systems Elk distribution and modeling in relation to roads A Five Year Record of Sedimentation in the Los Alamos Reservoir, New Mexico, Following the Cerro Grande Fire Implications of land disturbance on drinking water treatability in a changing climate: Demonstrating the need for source water supply and protection strategies. Forest fragmentation of the coterminous United States: assessing forest intactness through road density and spatial characteristics. Gap crossing decisions by forest songbirds during the post-fledgling period. Road traffic and nearby grassland bird patterns in a suburbanizing landscape. Seismic cutlines, changing landscape metrics, and grizzly bear landscape use in Alberta Comparative evaluation of experimental approaches to the study of habitat fragmentation effects Agricultural landscape simplification and insecticide use in the Midwestern United States. 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. A Five Year Record of Sedimentation in the Los Alamos Reservoir, New Mexico, Following the Cerro Grande Fire Elk distribution and modeling in relation to roads Implications of land disturbance on drinking water treatability in a changing climate: Demonstrating the need for source water supply and protection strategies. Fragments are not islands: patch vs landscape perspectives on songbird presence and abundance in a harvested boreal forest. Road traffic and nearby grassland bird patterns in a suburbanizing landscape. Seismic cutlines, changing landscape metrics, and grizzly bear landscape use in Alberta The influence of forest fragmentation and landscape pattern on American martens. Multi-scale effects of habitat loss and fragmentation on lesser prairie-chicken populations in the US souther Great Plains. Gap crossing decisions by forest songbirds during the post-fledgling period. 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 Changes in bird communities in boreal mixedwood forest: harvest and wildfire effects over 30 years. Modeling and field-testing of Ovenbird (Seiurus aurocapillus) responses to boreal forest dissection by energy sector development at multiple spatial scales. Agricultural landscape simplification and insecticide use in the Midwestern United States. Environmental Trends in British Columbia 2002 Forest fragmentation of the coterminous United States: assessing forest intactness through road density and spatial characteristics. Correlates of Vertebrate Extinction Risk in Canada. Landscape indictors of human impacts to riverine systems