Treesearch

Sequoia and Kings Canyon National Parks are among the premier destinations in the world for wilderness travel and camping. Over 93% of the spectacular mountain country that make up these parks has been designated as wilderness, with another 4% managed as wilderness. The parks are home to the highest peak in the lower 48 states, Mt. Whitney (14,495 feet), a 97-mile stretch of the famous John Muir Trail and also 101 miles of the Pacific Crest Trail. In all, there are more than 700 miles of maintained trail in the parks, as well as numerous opportunities to travel off trails. Wilderness...

In many U.S. federally designated wilderness areas, wildfires are likely to burn of their own accord due to favorable management policies and remote location. Previous research suggested that limitations on fire size can result from the evolution of natural fire regimes, specifically in places where fuels were recently reduced by previous burning. To explore the broader-scale importance of fire management on wilderness landscapes, we selected three study regions representing diverse ecosystems in the western U.S. and modeled the change in fire size distributions across a gradient defined...

Projected increases in wildfire and other climate-driven disturbances will affect populations and communities worldwide, including host-parasite relationships. Research in temperate forests has shown that wildfire can negatively affect amphibians, but this research has occurred primarily outside of managed landscapes where interactions with human disturbances could result in additive or synergistic effects. Furthermore, parasites represent a large component of biodiversity and can affect host fitness and population dynamics, yet they are rarely included in studies of how vertebrate hosts...

We examined temporal and spatial patterns of terrestrial amphibian species abundances and individual movements in western Oregon managed headwater forest stands using artifi cial cover object (ACO) arrays. Using mark-recapture methods, we estimated the eff ects of species and seasonality on apparent survival rates and recapture probabilities. We captured, marked, and released over 300 individual salamanders during 18 site visits between 2006 and 2009. Th ese captures were dominated by three plethodontid species: Ensatina (Ensatina eschscholtzii), Western Red-backed Salamander (Plethodon...

Th ere are emerging concerns for wildlife species associated with forested headwater systems. Given that headwater streams comprise a large portion of the length of fl owing waterways in western Oregon forests, there is a need to better understand how forest management aff ects headwater forest taxa and their habitats. Forest management strategies that consist of only partial canopy removal and retention of riparian buff ers may help ameliorate management eff ects on headwaters, especially relative to historical clearcutting practices. Our study investigated eff ects of upland forest...

Down wood provides important faunal microhabitat in forests for many invertebrate taxa, small mammals, and amphibians. Habitat suitability of down wood as refugia is an increasing concern in managed forests of the US Pacifi c Northwest, where overstory reduction may result in both reduced down wood recruitment and increased temperatures within logs, which may make them unsuitable habitat refugia. We examined temperature regimes inside logs and soils to assess buff ering capabilities against summer temperature extremes and potential habitat suitability for plethodontid salamanders. Temperatu...

Variable-density thinning has received a lot of public attention in recent years and has subsequently become standard language in most of the Willamette National Forest’s timber management projects. Many techniques have been tried, with varying on-the-ground successes. To accomplish variable-density thinning, the McKenzie River Ranger District currently uses combinations of techniques such as skips, gaps, dominant tree releases, variable thinning prescriptions, designation by description (DxD), and individually marked trees within the same harvest unit. Th e major challenge associated with...

Density management through thinning is the most important tool foresters have to aff ect stand development and stand structure of existing stands. Reducing stand density by thinning increases the growing space and resource availability (e.g., light, water, and nutrients) for the remaining trees. Th is can result in increased average tree growth. More available site resources can also encourage the development of understory vegetation and trees. Alternatively, the highest amounts of stand volume (or tree biomass) growth will generally occur when the site is fully occupied. The competition...

Since the early 1990s, several studies have been undertaken to determine the planning requirements, productivity, costs, and residual stand damage of harvest operations in thinning treatments designed to promote development of complex forest structure in order to enhance ecological functioning and biological diversity. Th ese studies include the Oregon State Universityled cooperative Coastal Oregon Productivity Enhancement (COPE) project, the Willamette (National Forest) Young Stand Project (WYS), and the Siuslaw (National Forest) Th inning and Underplanting for Diversity (STUDS) project....

Headwater streams and adjacent riparian areas provide reproductive, foraging, and dispersal habitat for many forest-dependent species, especially amphibians. Although previous studies have shown that the composition of aquatic and riparian animal communities is associated with spatial and temporal patterns of stream fl ow, the relationships among stream fl ow, climate, and thinning are not well known. We characterized stream flow conditions associated with 78 headwater reaches in 13 managed forest sites in the Coast Range and western Cascade Range, Oregon, USA, tracked periodically over a...