Skip to main content
Advanced Search

Filters: Categories: Publication (X) > Tags: {"type":"Taxa Keyword"} (X)

168 results (541ms)   

View Results as: JSON ATOM CSV
thumbnail
Synopsis: This report evaluates habitat requirements of the American badger according to parameters of soil texture, graminoid cover, slope, and proximity to roads. Badgers tend to prefer sandy loam and silty loam, medium and moderately coarse textured soils. In terms of graminoid coverage, badgers generally prefer open grassland habitat, but can also be found in agriculturally dominated landscapes containing isolated pockets of Richardson 's ground squirrel colonies. Graminoid coverage of 23% was chosen as the minimum requirement for suitable badger habitat. As slope increases, habitat suitability decreases to a point at which the likelihood of badgers existing there (i.e. cliffs and badlands) is extremely low...
thumbnail
Synopsis: Agricultural intensification and expansion are major present and future causes of global ecosystem disruption. Natural and semi-natural reserve areas in agroecosystems are thought to be important for preservation of essential ecosystem services such as pollination, but data about land use patterns and pollinator abundance are lacking. We assessed wild bee populations in canola fields in an agriculturally intense area where virtually all land was either tilled agricultural fields or semi-natural grazed pasturelands, with the expectation that mosaics of land use types may better support ecosystem services than homogenous crop areas. Fields were chosen in two categories, five with little or no pastureland...
thumbnail
Synopsis: The goal of this study was to examine contaminant loadings associated with stormwater runoff from recently burned areas in urban fringe areas of southern California, to derive regional patterns of runoff and contaminant loadings in this context. Postfire stormwater runoff was sampled from five wildfires that each burned between 115 and 658 km2 of natural open space between 2003 and 2009. The area is characterized by classic Mediterranean climate conditions of relatively mild to cool wet winter and warm to hot dry summers. Between two and five storm events were sampled per site over the first one to two years following the fires for basic constituents, metals, nutrients, total suspended solids, and polycyclic...
Conclusions:High proportions of native grass and low proportions of shrub cover are critical habitat components for maintaining viable sharp tailed grouse populations. *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:Ideal shrub cover ranges from 5% to 15% and the ideal proportion of native grassland cover is >75% for sharp-tailed grouse*.
Conclusions:Forest clearcutting differentialy affects birds of different ages. There is a threshold distance between reserves below which birds do not mind crossing clear cuts, making corridors more important as clearcut area and distance between forest reserves expandsThresholds/Learnings:
Conclusions:Results indicated that system and species-specific considerations are important when assessing the potential outcome of habitat loss and fragmentation on regional biotaThresholds/Learnings:
Conclusions:Report summarizes studies on the impacts of agricultural land use on water quality within Alberta. The impacts of agricultural activities on water quality depend strongly on the amount and distribution of land under cultivation, as well as other measures of agricultural intensity such as fertilizer expenses, chemical expenses and animal unit densities. Generally, streams draining watersheds with more agriculture had higher concentrations of nutrients, bacteria, and pesticides.Thresholds/Learnings:
Conclusions:The effects of landscape fragmentation depend on habitat structure, landscape context, the predator community, and the impact of parasitism. Because these factors differ substantially in western ecosystem compared to eastern forest ecosystems, it is difficult to make universal generalizations about the effects of landscape fragmentation on ecosystem processes and wildlife dynamicsThresholds/Learnings:
thumbnail
Synopsis: Wind erosion is considered a problem when the erosion level exceeds the tolerable limit for the soil or when the erosion level is great enough to damage the crops being grown. Wind erosion control must be tailored to each farming situation and may be achieved through a combination of practices that ultimately create isolated fields, the key to wind erosion control systems. Wind erosion control measures can be grouped into four components: (1) tree and shrub windbreaks; (2) annual and perennial vegetative barriers; (3) strip cropping and trap strips; and (4) crop residues and cover crops. Wind control system design involves 4 basic principles: (1) erosion rates are predicted using the wind erosion equation;...
thumbnail
Conclusions: The study recorded flushing responses (whether or not an animal fled in response to disturbance) and flush distances of 6 species of diurnal raptors exposed to walking and vehicle disturbances in order to calculate minimum distances for species-specific buffer zones. In general, walking disturbances resulted in more flushing than vehicle disturbances for all species except the prairie falcon. For walking disturbances, a linear relationship existed between flight distance and body mass, with lighter species flushing at shorter distances; however, this trend did not hold for vehicle disturbance. Birds flushed at much shorter distances in response to approaching vehicles. Thresholds/Learnings: Buffer...
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.
Conclusions:Within a watershed, about 10% of development is not subject to drainage regulations resulting in cumulative effects from urbanization that significantly degrade watersheds. Instead of regulatory thresholds (e.g. 10% EIA), process controls are required to mitigate the impacts of urbanization on aquatic systems. Without these controls, strict development limits are the only way to limit watershed degradation.Thresholds/Learnings:The study cautions against the use of discrete “thresholds” to predict specific physical and biological effects, but does suggest that thresholds are appropriate indicators for when the perception and tolerance of watershed impacts triggers a regulatory response.
Conclusions:Loss of wetland cover over a 40 year period resulted in increased peak flows, increased sediment, phosphorus and nitrogen flows, and decreased waterfowl populations.Thresholds/Learnings:
Conclusions:Woodland caribou cross roads less than expected for all time periods except calving and use areas close to roads less frequently than expected. Roads are semipermeable barriers to caribou movement with the greatest barrier effects occurring during late winter.Thresholds/Learnings:
Conclusions:Adult mortality appeared to be largely the result of predation, with cougars accounting for half of the known-cause mortalities. The much higher rate of mortality observed in the more developed portion of the study area supports a link between predation and forestry development.Thresholds/Learnings:
thumbnail
Synopsis: Windbreaks are a major component of successful agricultural landscapes. At the farm scale, they help control erosion and blowing snow, improve animal health and survival under winter conditions, reduce energy consumption of the farmstead, and enhance habitat diversity. At a landscape scale, they provide habitat for various types of wildlife and have the potential to contribute significant benefits to the carbon balance equation, thereby easing the economic burdens associated with climate change. The effectiveness of a windbreak is determined partially by its external structure including its height, length, orientation, continuity, width, and cross-sectional shape and partially by its internal structure...
thumbnail
Conclusions: Caribou demonstrated patterns of avoidance near linear features such as pipelines, roads, and other oil field structures. Females demonstrated heightened avoidance, especially during calving seasons. Thresholds/Learnings: Synopsis: This study documented the behavioural reactions of caribou to oil development in the circumpolar regions of the northern hemisphere. Researchers observed patterns of avoidance near linear features such as pipelines, roads, and other oil field structures. Female caribou, especially those accompanied by calves avoided these areas in particular. Male caribou were more apt to occupy areas influenced by oil field structures and activity. In summary, the patterns oil field development...
thumbnail
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...
Conclusions:Chemical concentrations, turbidity, changes in microclimate, and sediment production were affected to varying degrees by forest harvesting. No significant differences were found between pre-harvest and post-harvest concentrations except for calcium which was 5 times higher and sodium which was 20 times higher in the harvested watersheds. Concentrations declined over the 3 year post-harvest span.Turbidity and suspended sediment increased with road construction but declined rapidly to nearly background levels after 2 years. Air temperature increased after harvesting in all of the smaller watersheds but stream temperature was not affected.Thresholds/Learnings:
thumbnail
Conclusions: Report identifies regional patterns of habitat disturbance, land use practices, and population trends relative to greater sage-grouse. In general, the most important landscape characteristics influencing sage-grouse populations are the proximity of leks (areas in which males perform to nesting habitat for and The report examined findings from studies that indicate several area and distance specific conservation thresholds for maintaining viable sage-grouse habitat. Thresholds/Learnings: Male sage-grouse prefer sod-forming grasses or bare ground for leks; female sage-grouse prefer dense sagebrush stands surrounding leks for nesting; gentle terrain characterized by <10% slope; <5% of existing sagebrush...
map background search result map search result map Caribou in the Changing North Conservation Assessment of Greater Sage-Grouse and Sagebrush Habitats Demographic models of the northern spotted owl (Strix occidentalis caurina) Can pastureland increase wild bee abundance in agriculturally intense areas? Response of wintering grassland raptors to human disturbance. Stormwater contaminant loading following southern California wildfires Windbreaks in North American Agricultural Systems Design and use of field windbreaks in wind erosion control systems American Badger. Response of wintering grassland raptors to human disturbance. Demographic models of the northern spotted owl (Strix occidentalis caurina) Stormwater contaminant loading following southern California wildfires Conservation Assessment of Greater Sage-Grouse and Sagebrush Habitats Caribou in the Changing North Windbreaks in North American Agricultural Systems Design and use of field windbreaks in wind erosion control systems