Treesearch

The purpose of this study was to compare the sensitivity of nlodelled area burned to environmental factors across a range of independently-developed landscape-fire-succession models. The sensitivity of area burned to variation in four factors, namely terrain (flat, undulating and mountainous), fuel pattern (finely and coarsely clumped), climate (observed, warmer & wetter, and warmer & drier) and weather (year-to-year variability) was determined for four existing landscape-fire-succession models (EMBYR, FIRESCAPE, LANDSUM and SEM-LAND) and a new model implemented in the LAMOS inodelling...

Estimates of forest canopy cover are widely used in forest research and management, yet methods used to quantify canopy cover and the estimates they provide vary greatly. Four commonly used ground-based techniques for estimating overstory cover - line-intercept, spherical densiometer, moosehorn, and hemispherical photography - and cover estimates generated from crown radii parameters of the western Cascades variant of the Forest Vegetation Simulator (FVS) were compared in five Douglas-fir/western hemlock structure types in western Oregon. Differences in cover estimates among the ground-base...

Scaling biogeochemical processes to regions, continents, and the globe is critical for understanding feedbacks between the biosphere and atmosphere in the analysis of global change. This includes the effects of changing atmospheric carbon dioxide, climate, disturbances, and increasing nitrogen deposition from air pollution (Ehleringer and Field 1993, Vitousek et al. 1997). Quantification and uncertainty analysis of carbon pools and fluxes by terrestrial biota is needed to guide policy and management decisions. Unanswered questions include: (1) how and where is the terrestrial biosphere...

This guide presents a classification of the deep canyon and subalpine riparian and wetland vegetation types of the Malheur, Umatilla, and Wallowa-Whitman National Forests. A primary goal of the deep canyon and subalpine riparian and wetland classification was a seamless linkage with the midmontane northeastern Oregon riparian and wetland classification provided by Crowe and Clausnitzer in 1997. The classification is based on potential natural vegetation and follows directly from the plant association concept for riparian zones. The 95 vegetation types classified across the three national...

The goal of this study was to understand relationships between salmon habitat and landscape characteristics, summarized at multiple spatial scales, in a montane basin where forestry is the dominant land use. Specific study objectives were to (1) examine differences among spatial scales for landscape characteristics described with relatively coarse-resolution data, (2) compare the proportion of variation in stream habitat features explained by landscape characteristics summarized within and among different spatial scales, and (3) assess regression residuals for spatial autocorrelation.

We studied bushy-tailed woodrats (Neotonza cinerea occidentalis) in the eastern Washington Cascade Range to estimate their density and survival in 3 typical dry forest cover types. We predicted woodrat density to be high, moderate, and low in mature mixed-conifer forests, young mixed-conifer forests, and open ponderosa pine forests, respectively. We live-trapped on 8 x 8 grids (280 m) over an 8-day period each autumn for 4 years to obtain Huggins mark-recapture estimates of woodrat density. We captured woodrats 617 times and marked 193 individual woodrats in 12 sample stands during 42,165...

The hydrologic and biogeochemical responses of forested watersheds to inputs of rainfall and snowmelt can be an indicator of internal watershed function. In this study, we assess how the quantity and quality, both chemical and spectroscopic, of stream water DOC changes in response to a 6-day storm event during the wet season of 2003 in three small (

In many fire-dependent forests in the United States, changes occurring in the last century have resulted in overstory structures, conifer densities, down woody structure and understory plant communities that deviate from those described historically. With these changes, many forests are presumed to be unsustainable. Broad-scale treatments are proposed to promote stand development on trajectories toward more sustainable structures. Yet little research to date has identified the effects of these restoration treatments, especially in low elevation dry ponderosa pine (Pinus ponderosa) and...

The Community Socioeconomic Information System (CSIS) is a tool that allows users to retrieve 1990 and 2000 U.S. census data to examine conditions and trends for communities in western Washington, western Oregon, and northern California. The tool includes socioeconomic data for 1,314 communities in the entire region, including incorporated and unincorporated places. The tool delivers socioeconomic data using mapping and database features. In addition to providing data for one community, the tool produces community-level data at a variety of scales, including communities in areas surrounding...

Oregon white oak woodlands and savannas in the Puget Sound Region have been dramatically reduced in area owing in part to the invasion and eventual dominance of Douglas-fir in oak stands after Native American burning practices ended. We initiated a study in 2001 to examine the response of overtopped oaks to three types of release (full, partial, control) from Douglas-fir. Full and partial release treatments increased oaks' stem growth and acorn production and resulted in the formation of new branches. Our findings indicate that these overtopped oaks are capable of recovery, even after an...