Treesearch

At Lick Creek, from 1906 until the 1980’s carefully guided harvesting had selectively removed large trees, retaining vigorous ones but allowing unmerchantable small trees to proliferate. The small trees were occasionally thinned by hand, but this was expensive and generated hazardous slash fuels. In contrast, for hundreds if not thousands of years prior to 1900, frequent low-intensity fires had shaped the forest by killing most of the small trees and maintaining a low level of fuel loadings (Agee 1993; Arno and others 1995, 1997). Thus, the silvicultural activities evaluated by Gruell and...

Estimates of percent canopy cover generated by the Forest Vegetation Simulator (FVS) are corrected for crown overlap using an equation presented in this paper. A comparison of the new cover estimate to some others is provided. The cover estimate is one of several describing stand structure. The structure descriptors also include major species, ranges of diameters, tree heights, and heights to crown base for as many as three significant height strata. From these data a structural class is assigned to the stand using concepts defined by O'Hara and others (1996) with some subsequent enhancemen...

Birds are sensitive indicators of vegetation conditions because they have relatively narrow habitat requirements (Martin and Finch 1995). Resident bird populations are relatively stable in winter (Ralph et al. 1993) and more closely associated with specific habitats than during summer (Huff et al. 1991, Manuwal and Huff 1987). Winter can be critical for birds in northern latitudes because food and cover have restricted distribution or abundance (Chambers and McComb 1997). If birds are year-residents, land managers must understand their winter habitat needs to insure that sufficient habitat...

Since its development by Jim Bradley in the late 1970s, the Impact Monster, a wilderness education skit designed to teach minimum impact techniques, has been used as a wilderness education tool by federal land management agencies. This paper reports on an evaluation of the perceived effectiveness of the Impact Monster program and its content. Results indicate that the Impact Monster program remains a widely used wilderness education tool to teach appropriate wilderness behavior. In addition, the program is rated good to excellent by most study participants. Most participants considered a...

A single ponderosa pine tree found in the central Black Hills of SouthDakota revealed its age of more than 700 years by its tree rings taken from coring in 1992. The purpose of this study was to examine historic climatic patterns from the 13th century through most of the 20th century as inferred from ring widths of this and other nearby trees. The steep, rocky site where this tree was found helped this tree and its cohorts survive fires and other damaging agents. Our analysis indicated that both dry and wet spells of longer duration andmagnitude than the 1930’s drought have occurred...

The Central Arizona Highlands have been the focus of a wide range of research efforts designed to learn more about the effects of natural and human induced disturbances on the functioning, processes, and components of the region's ecosystems. The watershed research spearheaded by the USDA Forest Service and its cooperators continues to lead to a comprehensive understanding of the region's ecology, and to formulation of management guidelines that meet the increasing needs of people in the region, and throughout the Southwestern United States. This report assembles the pertinent details of...

Water use in the United States to the year 2040 is estimated by extending past trends in basic water-use determinants. Those trends are largely encouraging. Over the past 35 years, withdrawals in industry and at thermoelectric plants have steadily dropped per unit of output, and over the past 15 years some irrigated regions have also increased the efficiency of their water use. Further, per-capita domestic withdrawals may have finally peaked. If these trends continue, aggregate withdrawals in the U.S. over the next 40 years will stay below 10% of the 1995 level, despite a 41% expected...

This report documents trends in wildlife resources for the nation as required by the Renewable Resources Planning Act (RPA) of 1974. The report focuses on recent historical trends in wildlife as one indicator of ecosystem health across the United States and updates wildlife trends presented in previous RPA Assessments. The report also shows short- and long-term projections of some wildlife for documenting expected trajectories of resource change. National trends in four attributes of wildlife resources, including habitat, population, harvest, and users, set the context within which...

FBASE is a microcomputer relational database package that handles data collected using the R1/R4 Fish and Fish Habitat Standard Inventory Procedures (Overton and others 1997). FBASE contains standard data entry screens, data validations for quality control, data maintenance features, and summary report options. This program also prepares data for importation into an ARC/INFO Geographic Information System. Users have easy access to their habitat inventory data in both a raw and summarized format. FBASE is a stand-alone program and has minimal requirements for RAM and hard drive space,...

This assessment describes northern goshawk (Accipiter gentilis) habitat in the State of Utah. Because of fire exclusion, insect and disease epidemics, timber harvest, livestock grazing, or a combination of these factors the forests and woodlands of Utah have changed drastically since the early 1900's. Forests are now dominated by mid- and late successional species (Douglas-fir, white fir, and subalpine fir) rather than the early successional species (lodgepole and ponderosa pine). Along with these changes came suspected declines in goshawk populations. Goshawk habitat in Utah was assessed...