coliform bacteria in sierra nevada wilderness lakes and streams: what is the impact of backpackers, pack animals, and cattle?the presence of coliform bacteria indicates a watershed risk for harboring microbes capable of causing human disease. we hypothesized that water from watersheds that have different human- or animal-use patterns would have differing risks for the presence of coliform bacteria. methods; water was collected in wilderness areas of the sierra nevada range in california. a total of 60 sites from lakes or streams were selected to statistically differentiate the risk categories: 1) high use by backpacke ...200616538940
using forest inventory data to assess fisher resting habitat suitability in california.the fisher (martes pennanti) is a forest-dwelling carnivore whose current distribution and association with late-seral forest conditions make it vulnerable to stand-altering human activities or natural disturbances. fishers select a variety of structures for daily resting bouts. these habitat elements, together with foraging and reproductive (denning) habitat, constitute the habitat requirements of fishers. we develop a model capable of predicting the suitability of fisher resting habitat using ...200616826999
risk factors for coliform bacteria in backcountry lakes and streams in the sierra nevada mountains: a 5-year provide a 5-year longitudinal assessment of risk of acquiring disease from sierra nevada wilderness area lakes and streams. this study examines the relative risk factors for harmful water microorganisms, using coliforms as an indicator.200818513116
using topography to meet wildlife and fuels treatment objectives in fire-suppressed landscapes.past forest management practices, fire suppression, and climate change are increasing the need to actively manage california sierra nevada forests for multiple environmental amenities. here we present a relatively low-cost, repeatable method for spatially parsing the landscape to help the u.s. forest service manage for different forest and fuel conditions to meet multiple goals relating to sensitive species, fuels reduction, forest products, water, carbon storage, and ecosystem restoration. usin ...201020872142
canine distemper in an isolated population of fishers (martes pennanti) from california.four fishers (martes pennanti) from an insular population in the southern sierra nevada mountains, california, usa died as a consequence of an infection with canine distemper virus (cdv) in 2009. three fishers were found in close temporal and spatial relationship; the fourth fisher died 4 mo later at a 70 km distance from the initial group. gross lesions were restricted to hyperkeratosis of periocular skin and ulceration of footpads. all animals had necrotizing bronchitis and bronchiolitis with ...201223060505
conservation of avian diversity in the sierra nevada: moving beyond a single-species management a result of past practices, many of the dry coniferous forests of the western united states contain dense, even-aged stands with uncharacteristically high levels of litter and downed woody debris. these changes to the forest have received considerable attention as they elevate concerns regarding the outcome of wildland fire. however, attempts to reduce biomass through fuel reduction (i.e., thinning of trees) are often opposed by public interest groups whose objectives include maintaining habi ...201323667579
historical and contemporary dna indicate fisher decline and isolation occurred prior to the european settlement of california.establishing if species contractions were the result of natural phenomena or human induced landscape changes is essential for managing natural populations. fishers (martes pennanti) in california occur in two geographically and genetically isolated populations in the northwestern mountains and southern sierra nevada. their isolation is hypothesized to have resulted from a decline in abundance and distribution associated with european settlement in the 1800s. however, there is little evidence to ...201223300783
regional variation in home-range-scale habitat models for fisher (martes pennanti) in california.we analyzed recent survey data and mapped environmental variables integrated over a home range scale of 10 km2 to model the distribution of fisher (martes pennanti) habitat in california, usa. our goal was to identify habitat factors associated with the current distribution of fishers in california, and to test whether those factors differ for widely disjunct northern and southern populations. our analyses were designed to probe whether poor habitat quality can explain the current absence of fis ...200718213963
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