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Conclusions: Valleys are the only areas capable of sustaining sufficient habitat for the butterfly species, Weidemeyer's Admiral. Consequently, all other areas (i.e. plains, uplands, benches, escarpments, plateaus) were deemed unsuitable. Additionally, areas devoid of shrub cover did not meet the habitat requirements of this specialized species. Thresholds/Learnings: Synopsis: Two variables were selected to model potential habitat for the butterfly species, Weidemeyer's Admiral. Topographical features derived from the Agricultural Region of Alberta Soils Inventory Database (AGRASID) and percent shrub cover derived from the Native Prairie Vegetation Baseline Inventory developed by Alberta Environment were used to...
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Conclusions: Richardson's ground squirrels prefer short grass native prairie / pasture but can also occupy small isolated islands within cropland. These squirrels prefer open prairies and tend to select against heavily forested areas. *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: A threshold amount of 20% graminoid coverage is the minimum suitable proportion for habitat suitability for Richarson's ground squirrel. Areas with less than 20% forest/shrub cover were considered sutiable habitat, while those greater than 40% were considered unsuitable*. ...
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Synopsis: The short-horned lizard is Alberta's only lizard. It is indigenous to semi-arid, short grass portions of the northern Great Plains and usually found in rather rough terrain. This report evaluated habitat suitability requirements for the short-horned lizard according to the following parameters: Topographical Features: Most of the daily movement patterns during the summer rarely exceeded 30m, and generally occurred along the slopes of the valleys or valley bottoms. Consequently, all valleys and all prairie habitat within 100m of valleys are considered the best potential habitat. Native Prairie Class: Native Prairie Class (NPC) is derived from the Native Prairie Vegetation Baseline Inventory developed...
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Conclusions: Report describes the development of a multi-metric, fish-based Index of Biological Integrity (IBI) to assess the health of aquatic ecosystems on the Battle River, Alberta. The IBI was highly sensitive to cumulative anthropogenic disturbance. Impaired integrity of fish assemblages was detectable at road densities as low as 0.7km/km2 Thresholds/Learnings: Impaired integrity of fish assemblages was detectable at road densities as low as 0.7km/km2. Synopsis: Report describes the development of a multi-metric, fish-based Index of Biological Integrity (IBI) to assess the health of aquatic ecosystems on the Battle River, Alberta. The IBI was highly sensitive to cumulative anthropogenic disturbance. Impaired...
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Conclusions: Elk consistently selected for big basin sagebrush, greasewood, and tree cover; and consistently selected against Wyoming sagebrush, mixed shrub, and bare ground/sand. Selection patterns were similar during the winter, except big basin sagebrush and mixed shrubs were selected in proportion to their availability. Elk tend to prefer areas characterized by edge habitat where quality forage and cover habitats are in close proximity to one another. Thresholds/Learnings: Elk use was highest in summer in areas characterized by diverse habitats and >2800m away from major roads. High use areas during winter were similar, although elk tended to use areas slightly closer to roads (>2100m away), which is largely...
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...
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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...
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Conclusions: The nature of the surrounding matrix contributes significantly to the degree of patch isolation; matrix modification may improve habitat connectivity and genetic distribution in fragmented landscapes. Thresholds/Learnings: Synopsis: This study challenges traditional assumptions about the uniform nature of the matrix, and the reliance on distance alone as an indicator of patch isolation, by testing whether the type of inter-patch matrix contributes significantly to patch isolation in butterfly populations. The author tracked the movement of six butterfly species between patches of meadow habitat through two natural matrix types (conifer forest and willow thicket). All taxa of butterflies studied responded...
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Conclusions: Habitat associations of prairie rattlesnakes appear to differ depending on whether snakes are hibernating, foraging, or reproducing. Most rattlesnake hibernacula occur within 4 km of a major river, drainage, or coulee, on relatively gentle slopes, but they migrate as far as 25 km away from dens in summer. High road densities present unfavorable habitat conditions for snakes because they are a significant cause of mortality. *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: Most rattlesnake hibernacula occur within 4 km of a major river, drainage, or...
Conclusions:The occurence of bull trout in mid-boreal stream is negatively related to two metrics of industrial activity: percent forest harvesting and road density. Bull trout abundance was positively related to elevation, and negatively related to stream width, slope, and levels of forest harvesting.Thresholds/Learnings:Timber harvest on up to 35% or more of individual subbasins is projected to result in the extripation of bull trout from up to 43% of stream reaches, especially those that support high densities of bull trout.
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Conclusions: The amount of upstream impervious area affects downstream fish habitat quality, channel stability, and water quality. The use of riparian buffers can reduce the magnitude of urban impacts, however, they cannot fully mitigate the impacts of upstream development in the watershed. Threshold percentages of impervious areas , as well as the percentage of forest cover in a watershed appear to be the most effective indicators of watershed health. Thresholds/Learnings: Impervious areas should be kept at or below 10% of a watershed, and forest cover should be maintained at a minimum of 65% in order to effectively mitigate the impacts of urbanization and development on watersheds. Synopsis: This paper articulates...
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Synopsis: This study examined the effect of road improvement and environmental variables on exotic and native plant diversity in roadside verges and adjacent semi-arid grassland, shrubland, and woodland communities of southern Utah. Researchers measured the cover of exotic and native species in roadside verges and both the richness and cover of exotic and native species in adjacent interior communities (50 meters beyond the edge of the road) along 42 roads stratified by level of road improvement (paved, improved surface, graded, and four-wheel drive track). Exotic species richness and cover were more than 50% greater, and the richness of native species 30% lower, at patch interiors adjacent to paved roads than those...
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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...
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Synopsis: This model is based around Native Prairie Cover types, and Soil Texture. Native Prairie Class (NPC) is derived from the Native Prairie Vegetation Baseline Inventory developed by AlbertaEnvironment. Class I is comprised of greater than 75% native prairie components (i.e. shrubs, graminoids, riparian areas, lakes, wetlands, and trees), Class 2 is 50 - 75%, Class 3 is 25 - 50%, Class 4 is 1 - 25%, and Class 5 is no native prairie components. Native prairie is probably the most important and limiting factor for ferruginous hawks. Although hawks have been found in areas that were primarily under cultivation), they were in close proximity to prairie in good condition. Overall NPC was selected over its individual...
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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...
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Conclusions: Emigration rates are closely tied to edge structure. Low contrast edges promote edge permeability Thresholds/Learnings: Synopsis: The behavior of two butterfly species, one habitat specialist and one habitat generalist, were tracked at four prairie edges to determine the extent to which edge structure affects emigration. The specialist species responded strongly to all edges, and was particularly affected by edge density. The generalist species responded strongly only to high contrast edges. Emigration rates are closely tied to edge structure. Therefore, promoting low contrast edges in conservation planning may positively influence edge permeability and species richness in highly fragmented landscapes.
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Synopsis: A simulation model, modified from percolation theory, was empirically tested to determine if population distribution patterns correlated with different landscape patterns, for different species across a landscape. Using two grasshopper species in a short-grass prairie of north-central Colorado, the experiment found that the threshold for population aggregation (random to clumped distribution) was differentially affected by dispersal ranges and habitat specialization for habitat generalists and habitat specialists, respectively. Habitat generalists aggregated differentially depending on dispersal abilities. Generalist species with good dispersal abilities aggregated when <35% of the landscape consisted...
Conclusions:Area requirements for wetland birds species vary depending on the degree of landscape heterogeneity and landscape pattern.Thresholds/Learnings:Black terns required 6.5 ha of suitable wetland habitat for nesting and foraging in heterogeneous landscapes, but required 15.4-32.6 ha in homogenous landscapes
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Conclusions: Areas for roosting are likely the most limiting factor for the Western Small-footed Myotis. Unlike various other bats, this myotis does not roost in trees, but rather under rocks, and in holes and crevices found in rock outcrops within cliffs and coulees. Summer roosts can be found in cavities within cliffs, boulders, vertical banks, the ground, and talus slopes. Distance to water was also a significant factor affecting habitat suitability Thresholds/Learnings: Habitat for western small-footed myotis bats is ideally located within 1000m of water. Habitat located >3000m from water is deemed unsuitable. Synopsis: Areas for roosting are likely the most limiting factor for the Western Small-footed Myotis....
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Conclusions: Four plant species have been tested in the majority of field evaluations, while plants native to the test area and perennial plants are particularly underrepresented. Native plants useful in restoration of rare ecosystems can increase natural enemy abundance and provide ecosystem services as much as widely recommended non-natives. Thresholds/Learnings: Synopsis: The intentional provision of flowering plants and plant communities in managed landscapes to enhance natural enemies is termed habitat management and is a relatively new but growing aspect of conservation biology. The focus of most habitat management research has been on understanding the role of these plant-provided resources on natural enemy...
map background search result map search result map Western Small-footed Myotis (Myotis ciliolabrum ciliolabrum) Butterfly responses to habitat edges in highly fragmented prairies of central Iowa. The matrix matters: effective isolation in fragmented landscapes. Weidemeyer's Admiral Influences of barriers to movement on within-watershed genetic variation of coastal cutthroat trout Maximizing ecosystem services from conservation biological control: The role of habitat management Seasonal distribution and habitat use patterns of elk in the Jack Morrow Hills Planning Area Ferruginous Hawk. Critical thresholds in species responses to landscape structure. Effects of landscape structure on nest predation on roadsides of a mid-western agroecosystem: a multi-scale analysis. Richardson's Ground Squirrel. Urbanization of aquatic systems: degradation thresholds, stormwater detection, and the limits of mitigation. A fish-based index of biological integrity for assessing river condition in Central Alberta Distribution of bark beetle, Trypodendron lineatum in a harvested landscape Short-horned Lizard Prairie Rattlesnake. Roads as conduits for exotic plant invasions in a semi-arid landscape. Influences of barriers to movement on within-watershed genetic variation of coastal cutthroat trout The matrix matters: effective isolation in fragmented landscapes. Seasonal distribution and habitat use patterns of elk in the Jack Morrow Hills Planning Area Urbanization of aquatic systems: degradation thresholds, stormwater detection, and the limits of mitigation. Distribution of bark beetle, Trypodendron lineatum in a harvested landscape A fish-based index of biological integrity for assessing river condition in Central Alberta Butterfly responses to habitat edges in highly fragmented prairies of central Iowa. Effects of landscape structure on nest predation on roadsides of a mid-western agroecosystem: a multi-scale analysis. Roads as conduits for exotic plant invasions in a semi-arid landscape. Critical thresholds in species responses to landscape structure. Western Small-footed Myotis (Myotis ciliolabrum ciliolabrum) Richardson's Ground Squirrel. Maximizing ecosystem services from conservation biological control: The role of habitat management