Treesearch

Pacific martens (Martes caurina) remain common in montane regions of the Pacific states, yet their distribution and status on the Olympic Peninsula, Washington, is uncertain. Between 1968–2008, six reliable marten detections exist; a dead juvenile female (2008) indicates martens were reproducing on the Peninsula within the last decade. To assess the status of martens, we describe carnivore surveys conducted from 1991–2008 (n = 223 stations). Additionally, we present results from three survey efforts we conducted from 2013–2016 (n = 747 stations). Although a suite of carnivore species was...

Microsites, local features having the potential to alter the environment for seedling regeneration, may help to define likely trends in high-elevation forest regeneration pattern. Although multiple microsites may exist in any alpine treeline ecotone (ATE) on any continent, some microsites appear to enhance density of seedling regeneration better than others. Known seedling regeneration stresses in the ATE include low temperature, low substrate moisture, high radiation, drought, wind, and both high and low snowfall amount. Relationships among various microsite types, annual temperature,...

Forested landscapes support a diversity of ecological processes and organisms having direct value to society. Assessments placing monetary value on forest processes and organisms can help inform management actions affecting these ecosystem services. The temperate rain forest ecoregion along the west coast of North America is home to five species of Pacific salmon Oncorhynchus spp. that support subsistence, personal-use, sport, and commercial fisheries. This study aimed to quantify the number and monetary value of commercially caught Pacific salmon originating from Alaska's Tongass and...

Integrating climate-smart principles into riparian and upland forest management can facilitate effective and efficient land use and conservation planning. Emerging values of forested headwater streams can help forge these links, yet climate effects on headwaters are little studied. We assessed associations of headwater discontinuous streams with climate metrics, watershed size, and forest-harvest treatments. We hypothesized that summer streamflow would decrease in warm, dry years, with possible harvest interactions. We field-collected streamflow patterns from 65 discontinuous stream...

The 1912 Douglas-Fir Heredity Study is one of the first studies undertaken by the US Forest Service, and one of the first forest genetics studies in North America. The study considers provenance variation of 120 parent trees from 13 seed sources planted at five test sites in the Pacific Northwest. The unique, long-term nature of the study makes it valuable to revisit and consider its biological and historical significance. This analysis considers how far climatically Douglas-fir populations may be moved without incurring unacceptable declines in growth and survival. Results indicate that...

National forest law enforcement officers regularly encounter “nonrecreational” campers whose tenure exceeds established stay limits (generally 2 weeks). Some long-term occupants are homeless and seek use of the forest as a temporary or long-term residence. Long-term nonrecreational campers present myriad concerns for forest officials, who seek to balance public access and resource conservation. In addition to biophysical impacts because of waste, disposal of chemicals, soil compaction, and damage to vegetation, nonrecreational campers can alter the social environment being shared with...

We tested the effects of phosphorus (P) fertilization and soil water on the growth, physiology, and total nitrogen (N) accumulation in N-fixing Scotch broom in Olympia, WA. We manipulated soil water and P availability via irrigation and fertilization, respectively, in a completely randomized 2 x 2 factorial on potted one-year old Scotch broom seedlings (n = 20) in an N-deficient sand. There was substantial evidence that increased-irrigation and P-fertilization had similar positive effects on N accumulation in Scotch broom approximately equally. High-irrigation rates were more often...

The practice of removing fire-killed trees from burned forests (or “postfire salvage logging”) has sparked public controversy and scientific debate when conducted on public lands in the United States. This review synthesizes the current scientific literature on the subject, providing an update to a 2000 literature review (PNW-GTR-486) and subsequent synthesis (PNW-GTR-776). Forty-three published studies are reviewed, summarizing ecological effects on wildlife, vegetation, fuels, soils, and other environmental variables. Several key themes emerge from the review and specific research topics...

Old forests are often patchily distributed in contemporary forested landscapes leading to conservation concerns for species dependent on these forest types. In the absence of broad-scale recovery of old forests, conservation initiatives have emphasized connecting forested landscapes to facilitate movement of genes or individuals. We assessed forest connectivity for a low-vagile arboreal rodent (red tree vole; Arborimus longicaudus), an obligate of old forests within a distinct population segment that is a candidate for listing under the US Endangered Species Act in the northern Oregon...

Exposure of nontarget wildlife to anticoagulant rodenticides (AR) is a global conservation concern typically centered around urban or agricultural areas. Recently, however, the illegal use of ARs in remote forests of California, USA, has exposed sensitive predators, including the federally threatened northern spotted owl (Strix occidentalis caurina). We used congeneric barred owls (S. varia) as a sentinel species to investigate whether ARs pose a threat to spotted owls and other old-forest wildlife in northern regions of the Pacific Northwest. We analyzed the liver tissue from 40 barred...