Treesearch

To provide information on comparative habitat use, we studied radiotagged Mexican spotted owls (Strix occidentalis lucida: n = 13) and great horned owls (Bubo virginianus: n = 4) in northern Arizona. Home-range size (95% adaptive kernel estimate) did not differ significantly between species during either the breeding or nonbreeding season. Home ranges overlapped considerably between species, but overlap in use of individual stands was limited. Relative area of 4 canopy-cover classes (

This proceedings contains 50 papers including an overview of shrubland ecosystem dynamics in a changing environment and several papers each on vegetation dynamics, management concerns and options, and plant ecophysiology as well as an account of a Jornada Basin field trip. Contributions emphasize the impact of changing environmental conditions on vegetative composition especially in the Jornada Basin and Chihuahuan Desert but also in other parts of western North America and the world.

This is a compendium of experimental forests, ranges, watersheds, and other outdoor laboratories, formally established by the Forest Service and Agricultural Research Service of the U.S. Department of Agriculture, and the universities in Utah, Idaho, and Montana. The purposes, histories, natural resource bases, data bases, past and current studies, locations, and who to contact for information are given for these areas that represent ecosystems ranging from deserts to cold subalpine forests.

A study of the water chemistry of Colorado Rocky Mountain Front Range alpine/subalpine lakes and streams in wilderness ecosystems was conducted during the summer of 1995 by the USDA Forest Service Arapaho and Roosevelt National Forests and Rocky Mountain Forest and Range Experiment Station, and the University of Colorado Institute of Alpine and Arctic Research. Data were collected to examine the water chemistry of Front Range high-elevation lakes and their sensitivity to atmospheric deposition, particularly nitrogen saturation. Water chemistry data from synoptic surveys of high-elevation...

Seral, fire dependent lodgepole pine (Pinus contorta Dougl.) communities are an important component of upper elevation forests throughout the Northern Rockies, where they cover 4 million acres, or about 17 percent of the land base. On the Bitterroot National Forest, lodgepole pine occurs mostly between 5,500 and 7,500 feet.

In many National Forests, much watershed restoration work involves road removal. Most National Forests have more roads than can be maintained with decreased budgets limiting the amount of roads that can be removed in any given year. Setting priorities for road closure based on the impacts and risks involved in closing, removing, or discontinuing maintenance has become a major challenge for forest managers. Stability and erosion risks are associated with unmaintained roads, and the same risks are associated with various removal strategies, such as culvert removal, surface ripping, outsloping...

The Columbia River Basin SUccession Model (CRBSUM) simulates broad-scale landscape changes as a consequence of various land management policies. CRBSUM is a spatially explicit, deterministic model with stochastic properties that simulates changes in vegetation cover types and structural stages on landscapes over long periods. CRBSUM was used to simulate coarse-scale landscape changes in the Interior Columbia River Basin as a result of four management scenarios called management futures. CRBSUM results have an inherent 1 to 5 percent variability because of the stochastic structure of the...

An ecological process model of vegetation dynamics mechanistically simulates longterm stand dynamics on coniferous landscapes of the Northern Rocky Mountains. This model is used to investigate and evaluate cumulative effects of various fire regimes, including prescribed burning and fire exclusion, on the vegetation and fuel complex of a simulation landscape composed of many stands. Detailed documentation of the model FIRE-BGC (a FIRE BioGeoChemical succession model) with complete discussion of all model parameters is followed with results of an application of the FIRE-BGC to a whitebark...

Presents highlights of Idaho's forest resources as of 1991. Describes the extent, condition, and location of the State's forests, focusing on timberland, includes statisticaltables providing data by area, ownership, forest type, species, volume, mortality, growth, and removals for timberland.

Riparian systems are a small but important resource in the southwestern USA and northern Mexico because of the diverse, dynamic, and complex biophysical habitats they provide. Wildfires have always produced the most significant impacts on riparian hydrology, geomorphology, and biology. Prescribed fires have not been used to any great extent in the Madrean Province for vegetation management in riparian systems. The unique geophysical characteristics of the Madrean Archipelago make it especially responsive to climatic events. Water yield, peakflow, and sediment yields after wildfires can be...