Treesearch

A key element of forest management is the maintenance of sufficient densities of snags (standing dead trees) to support associated wildlife. Management factors that influence snag densities, however, are numerous and complex. Consequently, accurate methods to estimate and model snag densities are needed. Using data collected in 2002 and Current Vegetation Survey (CVS) data collected in 1993-1996, we built models to explain variation in snag densities in northeast Oregon forests in relation to human access and associated management factors. Models that best explained snag densities differed...

The population of the Western Arctic Herd, estimated at 490,000 caribou (Rangifer tarandus granti) in 2003, is at its highest level in 30 years. Twenty permanent range transects were established in the winter range of the Western Arctic Herd in 1981 to assess the impacts of grazing. These transects were revisited in 1995 and 1996 (1995/96). Only 18 of the transects were re-located, so an additional 7 transects were established in 1996. In 2005, all 25 remaining transects were revisited. Lichen coverage dropped by a relative 45.1% between 1981 and 1995/96 and by an additional relative 25.6%...

The objective of this study was to quantity the extent and distribution of conifer cover increase in the Greater Yellowstone Ecosystem (GYE) between 1985 and 1999. In many locations across the GYE, conifer forests have increased in density and expanded into grasslands and shrub lands, but the actual extent of change is unknown. Accurate quantification is critical for assessment of ecological consequences, including biogeochemical cycling. The study area was located in the GYE, encompassing parts of Montana, Wyoming, and Idaho, U.S.A. We used a combination of aerial photos, Landsat satellite...

Two series of single and stereo photographs display a range of natural conditions and fuel loadings in sagebrush with grass and ponderosa pinejuniper types in central Montana. Each group of photos includes inventory information summarizing vegetation composition, structure, and loading; woody material loading and density by size class; forest floor depth and loading; and various site characteristics. The natural fuels photo series is designed to help land managers appraise fuel and vegetation conditions in natural settings.

A series of single and stereo photographs display a range of natural conditions and fuel loadings in evergreen and deciduous oak/juniper woodland and savannah ecosystems in southern Arizona and New Mexico. This group of photos includes inventory data summarizing vegetation composition, structure, and loading; woody material loading and density by size class; forest floor coverage and loading; and various site characteristics. The natural fuels photo series is designed to help land managers appraise fuel and vegetation conditions in natural settings.

This study evaluated the ability to generate prescriptions for a wide variety of stands when the goal is to reduce crown fire potential. Forest managers charged with reducing crown fire potential while providing for commodity and ecological production have been hampered by the complexity of possible management options. A program called Stand-Level Optimization with Multiple Objectives (SLOMO) was developed that uses a dynamic programming based algorithm to find near-optimal solutions for a number of problem formulations. Sixty-four stand types from eastern Oregon were evaluated with SLOMO...

As landscape-scale assessments and modeling become a more common method for evaluating alternatives in integrated resource management, new techniques are needed to display and evaluate outcomes for large numbers of stands over long periods. In this proof of concept, we evaluate the potential to provide financial support for silvicultural treatments by selling timber harvested during treatments designed to achieve nontimber objectives such as fire hazard reduction or wildlife habitat improvement. We introduce the concept of dimensionless indices to describe and compare physical accessibility...

Timber harvest may contribute to increased landsliding frequency through increased soil saturation or loss of soil strength as roots decay. This study assessed the effects of forest harvest on hillslope hydrology and linked hydrologic change before and after harvest with a simple model of hillslope stability. Observations of peak water table heights in 56 groundwater monitoring wells showed that soil saturation levels on hillslopes differed significantly with harvest intensity at one of the two study locations following 25, 75,and 100 percent harvest. Before the forest was cut 100 percent,...

Grazing cattle and timber harvest are common practices associated with forested rangelands. Therefore, the objective was to document the effects of timber harvest and herbivory on nutritional quality and botanical composition of steer diets in grand fir (Abies grandis [Dougl. ex D. Don] Lindl.) and ponderosa pine (Pinus ponderosa P. & C. Lawson) forests. Three replicated grand fir sites were arranged as a split-plot design; timber harvest treatments--1) no harvest (CON), 2) thinning (TH), 3) clearcut (CL)--were whole plots, and herbivory treatments--1) large ungulate grazing (Graze), 2)...

Earth observation with Landsat and other moderate resolution sensors is a vital component of a wide variety of applications across disciplines. Despite the widespread success of the Landsat program, recent problems with Landsat 5 and Landsat 7 create uncertainty about the future of moderate resolution remote sensing. Several other Landsat-like sensors have demonstrated applicability. in key fields of earth observation research and could potentially complement or replace Landsat. The objective of this paper is to review the range of applications of 5 satellite suites and their Landsat-like...