Treesearch

Post-fire rehabilitation treatments are commonly implemented after high-severity wildfires, but few data are available about the efficacy of these treatments. This study assessed post-fire erosion rates and the effectiveness of seeding, straw mulching, and contour felling in reducing erosion after a June 2000 wildfire northwest of Loveland, Colorado. Site characteristics and sediment yields were measured on 12 burned and untreated control plots and 22 burned and treated plots from 2000 to 2003. The size of the hillslope plots ranged from 0.015 to 0.86 ha. Sediment yields varied significantl...

After the 1998 North 25 Fire in the Wenatchee National Forest, eight study sites were established on steep, severely burned hillslopes to examine the effectiveness of postfire seeding and fertilizing treatments in increasing cover to reduce hillslope erosion, and to measure the nutrient content of the eroded sediment. At each site, four 4 by 9 m plots were located with four randomly applied treatments: seed (winter wheat, Triticum estivum) at 34 kg ha-1, fertilizer (75% ammonium nitrate and 25% ammonium sulfate) at 31 kg ha-1, seed and fertilizer, and untreated control. Sediment fences...

As part of the Russian FIRE BEAR (Fire Effects in the Boreal Eurasia Region) Project, replicated 4-ha experimental fires were conducted on a dry Scotch pine (Pinus sylvestris)/lichen (Cladonia sp.)/feathermoss (Pleurozeum schreberi) forest site in central Siberia. Observations from the initial seven surface fires (2000-2001) ignited under a range of burning conditions quantified the different fuel consumption and fire behavior characteristics (e.g., rate of spread, fireline intensity, etc.) possible in this particular forest fuel type. Experimental results and dendrochronological study of...

The Canada lynx (Lynx canadensis) was listed as a threatened species under the Endangered Species Act (USDI Fish and Wildlife Service 2000) in 2000 and is a species of conservation concern in the United States. New insights into the basic demography of southern lynx populations are needed. Data describing population age structures, including maximum ages, will allow biologists to better evaluate how well spatially isolated lynx populations can withstand cyclic or stochastic environmental variations, which may temporarily depress reproduction. Longevity data may also allow researchers to...

The contentious and litigious history associated with managing Northern Goshawks (Accipiter gentilis) has focused much research attention toward understanding this species’ life history. Results from these studies address many key information needs that are useful to managers and decision makers, but many pressing information needs exist to address key conservation questions. Our goal was to assess the current state of knowledge in light of recent research. We focused on published information, but we also include unpublished studies if necessary to address key information needs. We...

Snow-track surveys to detect rare carnivores require unequivocal species identification because of management and political ramifications associated with the presence of such species. Collecting noninvasive genetic samples from putative wolverine (Gulo gulo) snow tracks is an effective method for providing definitive species identification for use in presence-absence surveys. We completed 54 backtracks of approximately 1.4 km each and collected 169 hairs and 58 scats. Amplification rates of mitochondrial DNA (mtDNA) used for species identification were 62% and 24% for scats and hairs,...

Biological control of exotic invasive plants using exotic insects is practiced under the assumption that biological control agents are safe if they do not directly attack non-target species. We tested this assumption by evaluating the potential for two host-specific biological control agents (Urophora spp.), widely established in North America for spotted knapweed (Centaurea maculosa) control, to indirectly elevate Sin Nombre hantavirus by providing food subsidies to populations of deer mice (Peromyscus maniculatus), the primary reservoir for the virus. We show that seropositive deer mice...

Golden-mantled ground squirrels are commonly associated with high-elevation habitats near or above upper timberline. This species also occurs in fire-adapted, low-elevation forests that are targeted for forest health restoration (FHR) treatments intended to remove encroaching understory trees and thin overstory trees. Hence, the golden-mantled ground squirrel may be affected by FHR treatments, but little is known about its habitat associations within these forest types. We sampled mature western larch and ponderosa pine forests in western Montana to determine the macro- and microhabitat...

Environmental characteristics of a site may greatly influence the establishment and impact of biological control agents on the target weed. A biological control agent that is highly successful in one region may be virtually ineffective in another (Gurr and Wratten 2000). To maximize the use of limited availability of agents and financial resources, we should try to improve the success of our biological control releases by understanding the site requirements of individual biological control agents.

This paper summarizes our efforts to investigate the nature, behavior, and implications of positional error and attribute error in spatiotemporal datasets. Estimating the combined influence of these errors on map analysis has been hindered by the fact that these two error types are traditionally expressed in different units (distance units, and categorical units, respectively. We devised a conceptual model that enables the translation of positional error into terms of thematic error, allowing a simultaneous assessment of the impact of positional error on thematic error - a property that is...