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Conclusions: The negative effects of patch size and isolation on species may not occur until the landscape consists of less than 10% suitable habitat for birds, and 30% suitable habitat for mammals. Thresholds/Learnings: The negative effects of patch size and isolation on species may not occur until the landscape consists of less than 10% suitable habitat for birds, and 30% suitable habitat for mammals. Synopsis: This study involved a review of studies on birds and mammals in habitat patches in landscapes with different proportions of suitable habitat. The findings demonstrate that there exists a threshold in proportion of suitable habitat in the landscape, above which fragmentation becomes pure habitat loss....
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Conclusions: Watersheds with low indices of biotic integrity (IBI) have been heavily developed. The biggest factors contributing to low IBIs were the presence of large dams, introduced fish, and road density. Dams at low to middle elevations had the greatest effect on IBI. Thresholds/Learnings: Dams at low to middle elevations had the greatest effect on IBI. Synopsis: Researchers developed a watershed index of biotic integrity to evaluate the biological health of 100 watersheds in the Sierra Nevada of California. In general, watersheds with low indices of biotic integrity (IBI) have been heavily developed by hydraulic mining, agriculture, and hydroelectric dams. The biggest factors contributing to low IBIs were...
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Synopsis: Researchers analyzed variation in crop pollination services provided by native, unmanaged, bee communities on organic and conventional farms situated along a gradient of isolation from natural habitat. Pollination services from native bees were significantly, positively related to the proportion of upland natural habitat in the vicinity of farm sites, but not to any other factor studied, including farm type, insecticide usage, field size and honeybee abundance. The scale of this relationship matched bee foraging ranges. Stability and predictability of pollination services also increased with increasing natural habitat area. This strong relationship between natural habitat area and pollination services...
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Synopsis: The individual species and aggregate community contributions of native bees to crop pollination are documented, on farms that varied both in their proximity to natural habitat and management type (organic versus conventional). On organic farms near natural habitat, we found that native bee communities could provide full pollination services even for a crop with heavy pollination requirements (e.g., watermelon, Citrullus lanatus), without the intervention of managed honey bees. Agricultural intensification diminished these pollination services by roughly 3- to 6-fold. The decline of native bee pollination services with agricultural intensification resulted in significant reductions in both diversity and...
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Synopsis: This study examined the spatial patterns and factors influencing small terrestrial vertebrate road-kill aggregations in the Bow River Valley of Alberta, Canada. Mammal and bird road-kill indices were consistently higher on low volume parkway roads than on the high-speed, high volume Trans-Canada highway (TCH). Birds were more vulnerable to collisions than mammals on the TCH. Low volume parkway road-kills were less likely to occur on raised sections of road, and tended to occur close to vegetative cover far from wildlife passages and culverts. Highway sections with forested medians were less significant barriers to forest birds than open grassy medians. Since forest dwelling birds are reluctant to cross...
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Conclusions: The proportion of sage-grouse nests located within 3 vs 5 km suggested that a 5 km buffer around a lek encompassed the majority of nests. The results indicate that land managers should strive to maintain a 5 km buffer around known sage-grouse lek locations in order to ensure sage-grouse breeding success. Thresholds/Learnings: A 5000m buffer around sage-grouse leks encompassed the majority (64%) of sage-grouse nests. Synopsis: This study used radio-telemetry to determine nesting patterns of Greater Sage-Grouse relative to leks in a relatively contiguous sagebrush habitat in Wyoming. The proportion of nests located within 3 vs 5 km suggested that a 5 km buffer around a lek encompassed the majority of...
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Conclusions: Caribou mortalities attributed to wolf predation were generally closer to a corridor, indicating that linear corridors may enhance wolf predation efficiency. Therefore, caribou existing closer to linear corridors are at a higher risk of depredation than those farther from corridors. Thresholds/Learnings: Synopsis: This study tested the hypothesis that linear corridors affect caribou and wolf activities by examining the distribution of telemetry locations of caribou and wolves, as well as locations of caribou mortality and caribou predation by wolves relative to linear corridors caused by roads, seismic lines, power lines, and pipeline rights-of-way. Caribou mortalities attributed to wolf predation...
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Conclusions: When isolated, larger patch size correlates with higher species density and occurence in area-sensitive grassland birds Thresholds/Learnings: Synopsis: This paper examines the influence of landscape fragmentation and isolation of Conservation Reserve Program (CRP) grasslands on grassland breeding bird populations in the northern Great Plains states. The study explores the relationship between species occurrence and density, and patch size by tracking 15 bird species on 303 restored grassland areas. Locating CRP grassland fields near existing grasslands, or establishing one large CRP field rather than several small fields, benefits area-sensitive grassland bird species. Caveats: Inconsistent findings...
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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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Synopsis: This study examines the influence of landscape fragmentation on trophic cascades in southern California. Results indicate that, as habitat fragmentation negatively affects the persistence of coyote populations, the abundance of smaller meso-predators increase, resulting in higher mortality rates in scrub-breeding birds. Fragment size was a strong indicator of coyote abundance, and coyote abundance was a strong indicator of bird diversity, as coyotes kept down the number of meso-predators that prey on birds. The positive effect of fragment area and the negative effect of fragment age were the strongest determinants of bird diversity in this system. Conclusions: Fragment size correlates with coyote abundance,...
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Conclusions: Summarizes findings from a review of literature intended to identify critical thresholds for conservation based in empirical studies of landscape fragmentation. Presents a conceptual overview of landscape fragmentation and habitat loss, as well as guidelines and thresholds relating to landscape indicators such as patch size, habitat amount, edge effects, riparian buffers, and habitat connectivity. Thresholds/Learnings: Many. See Kennedy et al. 2003. Synopsis: This report summarizes findings from a review of literature intended to identify critical thresholds for conservation based in empirical studies of landscape fragmentation. In presenting a conceptual overview of landscape fragmentation and habitat...
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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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Synopsis: The objective of this study was to examine initial effects of the 2003 Lost Creek wildfire (southwestern Rocky Mountains of Alberta) on concentrations and production (yield and total export) of several nitrogen (N) forms, and to explore initial recovery of these effects within the first 3 years after the fire. During the first postfire year, nitrate (NO3–), dissolved organic nitrogen (DON), and total nitrogen (TN) concentrations in severely burned watershed streams were 6.5, 4.1, and 5.3 times greater, respectively, than those in reference streams. Weaker effects were evident for concentrations of ammonium (NH4+; 1.5 times) and total particulate nitrogen (TPN; 3.0 times). A rapid decline in mean watershed...
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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...
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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: There was a significant reduction in ovenbird pairing success at compressor sites (77%) compared with noiseless wellpads (92%). These differences were apparent regardless of territory quality or individual male quality. Noise interferes with a male's song, such that females may not hear the male's song at greater distances and/or females may perceive males to be of lower quality because of distortion of song characteristics Thresholds/Learnings: Synopsis: Anthropogenic noise is rapidly increasing in wilderness areas as a result of industrial expansion. This study assessed pairing success and age distribution of male ovenbirds, Seiurus aurocapilla, in the boreal forest of Alberta, Canada, in areas around...
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Conclusions: Prescribed burns did not supply the stream ecosystem with potentially important nutrient pulses that are often observed after wildfires. Prescribing higher severity burns to more closely mimic wildfires would enhance N cycling in productivity in N-limited headwater watersheds. Thresholds/Learnings: Synopsis: This study aimed to compare the short-term effects of spring prescribed burns and wildfires on Nitrogen cycling dynamics in headwater watersheds of central Idaho. Fire affected N dynamics in both terrestrial and aquatic components of the watershed ecosystem after wildfires but were limited to the terrestrial ecosystem after prescribed burns. Streamwater NO3 concentrations were affected significantly...
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Synopsis: Natural habitats are considered inherently indispensable to the global economy by conservationists, but few natural ecosystems afford direct and quantifiable economic benefits. Quantification of natural land value can provide compelling evidence favoring preservation over development. Wild bees are important pollinators of many crop plants, and natural patches in agroecosystems enhance pollinator services and crop yield. Bee abundance was greatest in canola fields that had more uncultivated land within 750 m of field edges and seed set was greater in fields with higher bee abundance. A cost–benefit model that estimates profit in canola agroecosystems with different proportions of uncultivated land is presented....
map background search result map search result map Chronic industrial noise affects pairing success and age structure of ovenbirds Seiurus aurocapilla. Area requirements of grassland birds: a regional perspective. Weidemeyer's Admiral Distribution of caribou and wolves in relation to linear corridors Conservation Thresholds for Land Use Planners Influences of barriers to movement on within-watershed genetic variation of coastal cutthroat trout Effects of spring prescribed burning and wildfires on watershed nitrogen dynamics of central Idaho headwater areas Seasonal distribution and habitat use patterns of elk in the Jack Morrow Hills Planning Area Spatial distribution of greater sage-grouse nests in relatively contiguous sagebrush habitats. Richardson's Ground Squirrel. Effects of habitat fragmentation on birds and mammals in landscapes with different proportions of suitable habitat: a review. A fish-based index of biological integrity for assessing river condition in Central Alberta Evaluating the biotic integrity of watersheds in the Sierra Nevada, California. Short-horned Lizard Crop pollination from native bees at risk from agricultural intensification The area requirements for an ecosystem serivce: crop pollination by native bee communities in California Pollinators provide economic incentive to preserve natural land in agroecosystems Wildfire Impacts on nitrogen concentration and production from headwater streams in southern Alberta's Rocky Mountains. Mesopredator release and avifaunal extinctions in a fragmented system. Spatial patterns and factors influencing small vertebrate fauna road-kill aggregations. Influences of barriers to movement on within-watershed genetic variation of coastal cutthroat trout Wildfire Impacts on nitrogen concentration and production from headwater streams in southern Alberta's Rocky Mountains. Seasonal distribution and habitat use patterns of elk in the Jack Morrow Hills Planning Area A fish-based index of biological integrity for assessing river condition in Central Alberta Distribution of caribou and wolves in relation to linear corridors Crop pollination from native bees at risk from agricultural intensification The area requirements for an ecosystem serivce: crop pollination by native bee communities in California Evaluating the biotic integrity of watersheds in the Sierra Nevada, California. Spatial patterns and factors influencing small vertebrate fauna road-kill aggregations. Spatial distribution of greater sage-grouse nests in relatively contiguous sagebrush habitats. Mesopredator release and avifaunal extinctions in a fragmented system. Chronic industrial noise affects pairing success and age structure of ovenbirds Seiurus aurocapilla. Pollinators provide economic incentive to preserve natural land in agroecosystems Area requirements of grassland birds: a regional perspective. Richardson's Ground Squirrel. Conservation Thresholds for Land Use Planners Effects of habitat fragmentation on birds and mammals in landscapes with different proportions of suitable habitat: a review.