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Conclusions: Habitat changes resulting from timber harvest have altered the predator–prey balance leading to asymmetric predation affecting the survivial rates of endangered mountain caribou Thresholds/Learnings: As young forest stands increase in proportion to old forests, caribou population densities and survival rates decline as they become increasingly vulnerable to predation and extripation. Synopsis: Timber harvesting in areas of Mountain Caribou habitat have created landscapes of early seral forests. Such habitat changes have altered the predator–prey balance resulting in asymmetric predation in which predators are maintained by alternative prey (i.e. apparent competition). This study estimates survival...
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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...
Conclusions:Severe fire regimes create essential habitat conditions for certain habitat specialists.Thresholds/Learnings:
Conclusions:Report reviews how forests and their management affect the quality and quantity of downstream municipal water supplies in the state of OregonThresholds/Learnings:When >25% of the watershed's forest cover is clearcut in a short period of only a few months, there is a measurable increase in annual streamflows from the watershed.
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Synopsis: Classical demographic methods applied to life history data on the northern spotted owl yield an estimate of the annual geometric rate of increase for the population of λ = 0.96 ± 0.03, which is not significantly different from that for a stable population (λ = 1.00). Sensitivity analysis indicates that adult annual survivorship has by far the largest influence on λ, followed by the probability that juveniles survive dispersal, and the adult annual fecundity. Substantial temporal fluctuations in demographic parameters have little effect on the long-run growth rate of the population because of the long adult life expectancy. A model of dispersal and territory occupancy that assumes demographic equilibrium...
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Most of these data were collected in order to create a database of tree locations for use in calibrating remote sensing tools and products, particularly dead tree detection tools and canopy species maps. Data include tree locations, species identification, and status (live, dead, and, if dead, sometimes includes information on foliage and twig retention). They are a collection of different sampling efforts performed over several years, starting in a period of severe drought mortality. One csv table is included that shows data and validation results for an additional dataset that was used to test the NAIP derived dead tree detection model that is associated with this data release. Locations are not included for that...
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Synopsis: This study monitored the response of a species of pine bark beetle, Trypodendron lineatum, to direct and indirect measures of habitat availability in a forest subjected to various levels of harvest intensities. Four stand types (conifer dominated, mixed, deciduous dominated, and deciduous dominated with conifer understory) were treated with four levels of harvest intensity (unharvested, 50%, 80%, and 90% harvested). Prior to harvest, the pine bark beetle was most abundant in stands with many host trees (conifer dominated stands). In the first and second summers after harvest, pine beetle abundance increased exponentially with percent spruce cover and the number of spruce stumps in the stand. Beetles were...
Conclusions:Habitat fragmentation results in demographic changes in plant populations associated wtih increased extinction risk.Thresholds/Learnings:Trillium populations in forest remnants within 65m of forest clear-cut edges have almost no recruitment of young plants
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Synopsis: This study evaluated the effects of landscape management on the spread of mountain pine beetle colonization in Banff National Park, Alberta, Canada. Researchers used annual aerial survey data and geo-referenced locations of colonized trees that were cut and removed to assess if the area colonized and the spatial extent of pine beetles differed between monitoring and management zones. Pine beetles were allowed to follow their natural course in the monitoring zone, while an extensive eradication program involving cutting and burning colonized trees was established in the management zone. Management resulted in no detectable effect on the scale of the zone. However, at the sub-zone scale, the area affected...
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Synopsis: Because recent bark beetle population eruptions have exceeded the frequencies, impacts, and ranges documented during the previous 125 years, researchers have been prompted to determine what factors trigger broad scale outbreaks, and how do these factors interact? How do human activities, such as forest management, alter these interactions, and thus the frequency, extent, severity, and synchrony of outbreaks? Extensive host tree abundance and susceptibility, concentrated beetle density, favorable weather, optimal symbiotic associations, and escape from natural enemies must occur jointly for beetles to surpass a series of thresholds and exert widespread disturbance. Eruptions occur when key thresholds are...
    map background search result map search result map Changes in landscape composition influence the decline of a threatened woodland caribou population Distribution of bark beetle, Trypodendron lineatum in a harvested landscape Effect of management on spatial spread of mountain pine beetle (Dendroctonus ponderosae) in Banff National Park. Cross-scale drivers of natural disturbances prone to anthropogenic amplification: the dynamics of bark beetle eruptions Watershed analysis of forest fragmentation by clearcuts and roads in a Wyoming forest Demographic models of the northern spotted owl (Strix occidentalis caurina) Conifer Forest Land Cover in the Wyoming Basins Ecoregional Assessment area Proportion of Conifer Forest Land Cover (1-km scale) in the Wyoming Basins Ecoregional Assessment area Proportion of Conifer Forest Land Cover (3-km scale) in the Wyoming Basins Ecoregional Assessment area Proportion of Conifer Forest Land Cover (5-km scale) in the Wyoming Basins Ecoregional Assessment area Proportion of Conifer Forest Land Cover (18-km scale) in the Wyoming Basins Ecoregional Assessment area Proportion of Conifer Forest Land Cover (270-m scale) in the Wyoming Basins Ecoregional Assessment area Proportion of Conifer Forest Land Cover 540-m scale) in the Wyoming Basins Ecoregional Assessment area Dead Tree Detection Validation Data from Sequoia and Kings Canyon National Parks Dead Tree Detection Validation Data from Sequoia and Kings Canyon National Parks Effect of management on spatial spread of mountain pine beetle (Dendroctonus ponderosae) in Banff National Park. Distribution of bark beetle, Trypodendron lineatum in a harvested landscape Watershed analysis of forest fragmentation by clearcuts and roads in a Wyoming forest Changes in landscape composition influence the decline of a threatened woodland caribou population Demographic models of the northern spotted owl (Strix occidentalis caurina) Conifer Forest Land Cover in the Wyoming Basins Ecoregional Assessment area Proportion of Conifer Forest Land Cover (1-km scale) in the Wyoming Basins Ecoregional Assessment area Proportion of Conifer Forest Land Cover (3-km scale) in the Wyoming Basins Ecoregional Assessment area Proportion of Conifer Forest Land Cover (5-km scale) in the Wyoming Basins Ecoregional Assessment area Proportion of Conifer Forest Land Cover (18-km scale) in the Wyoming Basins Ecoregional Assessment area Proportion of Conifer Forest Land Cover (270-m scale) in the Wyoming Basins Ecoregional Assessment area Proportion of Conifer Forest Land Cover 540-m scale) in the Wyoming Basins Ecoregional Assessment area Cross-scale drivers of natural disturbances prone to anthropogenic amplification: the dynamics of bark beetle eruptions