Treesearch

Dramatic fluctuations in food resources are a key feature of many habitats, and many species have evolved a movement strategy to exploit food resources that are unpredictable in space and time. The availability of food resources may be a particularly strong determinant of habitat quality for irruptive bird species. We studied the apparent foraging success of Black-backed Woodpeckers (Picoides arcticus), an irruptive species that responds opportunistically to pulsed food resources in burned forests and mountain pine beetle (MPB) infestations. Prior investigations revealed that the highest...

Establishment of native grasses is a primary objective of restoration in Pinus ponderosa var. scopulorum (P. & C. Lawson) forests in the southwestern United States. Interactions among native grasses and soil microorganisms generate feedbacks that influence the achievement of this objective. We examined soil chemical properties and communities of plants and soil microorganisms in clear-cuts and P. ponderosa stands thinned and maintained at low and medium tree densities for over 40 years along with high density (unthinned) stands. Phospholipid fatty acids (PLFA) in soils were analyzed to...

Monitoring is the collection of data over time. We monitor many things: temperatures at local weather stations, daily changes in sea level along the coastline, annual prevalence of specific diseases, sunspot cycles, unemployment rates, inflation, commodity futures-the list is virtually endless. In wildlife biology, we also conduct a lot of monitoring, most commonly measuring state variables that either directly or indirectly relate to the size and areal extent of wildlife populations. Most of these activities, both in wildlife biology and more generally, are not strongly targeted at...

The Fire, Fuel, and Smoke Science Program (FFS) of the U.S. Forest Service, Rocky Mountain Research Station focuses on fundamental and applied research in wildland fire, from fire physics and fire ecology to fuels management and smoke emissions. Located at the Missoula Fire Sciences Laboratory in Montana, the scientists, engineers, technicians, and support staff in FFS conduct national and international, cutting-edge work in wildland fire research and develop research and management tools and applications designed to improve understanding of wildland fire as well as safe and effective...

Residential development is a leading driver of land-use change, with important implications for biodiversity, ecosystem processes, and human well-being. We reviewed over 500 published scientific articles on the biophysical, economic, and social effects of residential development and open space in the US. We concluded that current knowledge of the effects of this type of development on social and natural systems is inadequate for achieving key objectives of sustainability, including a viable environment, a robust economy, and an equitable society. Most biophysical studies measured species-...

This chapter discusses the study of disturbance and succession as they relate to wildlife. As such, the discussion is confined to those disturbance processes that change the physical attributes of habitat, leading to a postdisturbance trajectory. However, even with this narrowing of the scope of disturbances discussed, there remain formidable obstacles prior to any coherent discussion of disturbance. The first, and most fundamental, is definitional: what constitutes disturbance and succession, and what is habitat? The concepts of disturbance, habitat, and succession are highly scale-depende...

Big sagebrush (Artemisia tridentata) is one of the most widespread and abundant plant species in the intermountain regions of western North America. This species occupies an extremely wide ecological niche ranging from the semi-arid basins to the subalpine. Within this large niche, three widespread subspecies are recognized. Montane ecoregions are occupied by subspecies vaseyana, while subspecies wyomingensis and tridentata occupy basin ecoregions. In cases of wide-ranging species with multiple subspecies, it can be more practical from the scientific and management perspective to assess...

Soil quality assessments are essential for determining impacts on belowground microbial community structure and function. We evaluated the suitability of active carbon (C), a rapid field test, as an indicator of soil biological quality in five paired forest stands (clear cut harvested 40 years prior and unharvested) growing on volcanic ash-cap soils in northern Idaho. Active C was compared with several traditional measures of soil microbial properties (microbial biomass, respiration, fungal hyphal biomass, bacterial number and biomass and PLFA community structure). Despite the significant...

Understanding the local context that shapes collective response to wildfire risk continues to be a challenge for scientists and policymakers. This study utilizes and expands on a conceptual approach for understanding adaptive capacity to wildfire in a comparison of 18 past case studies. The intent is to determine whether comparison of local social context and community characteristics across cases can identify community "archetypes" that approach wildfire planning and mitigation in consistently different ways. Identification of community archetypes serves as a potential strategy for...

Milder winters have contributed to recent outbreaks of Dendroctonus ponderosae in Canada, but have not been evaluated as a factor permitting concurrent outbreaks across its large range (ca.1500 9 1500 km) in the western United States (US). We examined the trend in minimum air temperatures in D. ponderosae habitats across the western US and assessed whether warming winters explained the occurrence of outbreaks using physiological and population models.