Treesearch

I investigated trends in bird species populations, guild structure, and bird communities along a riparian altitudinal cline in the Medicine Bow National Forest of southeastern Wyoming. Streamside habitats were divided into three elevational zones: low-elevation (2050 to 2260 m) cottonwood zone, mid-elevation (2290 to 2530 m) mixed shrub willow zone, and high elevation (2590 to 2990 m) subalpine willow zone. Vegetational complexity decreased from low to high zones, with loss of vertical habitat layers and increased foliage density and dominance of dwarf willows. Ground and lower-canopy...

The Fourth Biennial Wildlife Symposium was held at the historic Hotel Colorado in Glenwood Springs, Colorado, from February 6-8, 1989. In spite of some very cold wcather, the attendees came from many parts of the United States and Canada. As in previous years, they represented government, industry, academic and professional organizations, including nonprofits. Thorne Ecological Institute, with the co-sponsorship of several members of industry and other fine groups, is most pleased to present these Symposia every two years. They draw together biologists, wildlife managers and administrators...

I assessed relationships among habitat structure, nest-site selection, and reproductive outcome of House Wrens (Troglodytes aedon) by establishing three nest-box grids in riparian woodlands in southeastern Wyoming. Over a 3-year period, 37% of the boxes contained House Wren nests; 20% contained unused nests built by male House Wrens; and 42% were never used by wrens. Direct discriminant analyses separated three box-use groups (unused, 1-year use, 2- to 3-year use) and three nesting outcome possibilities (failure all years, 1-year success, 2- to 3-year success) along gradients of habitat...

I examined patterns of variance in habitat use and habitat overlap in 20 breeding bird species found along a riparian vegetational gradient in southeastern Wyoming to test whether habitat use in species differed (1) from availability of random habitat resources, (2) among elevational zones, and (3) between species that inhabited only one zone and species that occupied multiple zones. I sampled habitat features in bird territories and at random stations on 10 8.1-ha study grids distributed over an elevational gradient of 940 m. Principal components analysis was performed on both randomly...

It is difficult to design systems for national and global resource inventory and analysis that efficiently satisfy changing, and increasingly complex objectives. It is proposed that individual inventory, monitoring, modeling, and remote sensing systems be specialized to achieve portions of the objectives. These separate systems can be statistically linked to accomplish all objectives, which might simplify statistical designs and improve efficiency and timeliness. This might be accomplished using an estimation technique known as the Kalman filter, which combines a theoretical or empirical...

The 1989 National Silviculture Workshop was held in Petersburg, Alaska, and the Stikine Area of the Tongass National Forest. The purpose of the workshop was to discuss, review, and share information about the silvicultural challenges and opportunities facing the Forest Service in the coming decade.

Whitebark pine (Pinus albicaulis) is a long-lived tree inhabiting the upper subalpine forest and timberline zone on high mountains of Western North America. The species' habitat, life history, growth and yield, mortality factors, special uses, and genetics are described.

This is the third publication describing the BEHAVE system of computer programs for predicting behavior of wildland fires. This publication adds the following predictive capabilities: distance firebrands are lofted ahead of a wind-driven surface fire, probabilities of firebrands igniting spot fires, scorch height of trees, and percentage of tree mortality. The system includes a separate module for graphing moisture content of fine, dead fuels. Basic assumptions, limitations, and application of the prediction models are discussed. Previous publications in the BEHAVE series are BEHAVE: fire...

lncreases in annual streamflow and peak streamflows were determined on four small watersheds following timber harvesting and road building. The measured hydrologic changes are compared to those predicted by a methodology commonly used in the Forest Service's Northern Region, the equivalent clearcut area procedure. lncreases in peak streamflows are discussed with respect to their potential to modify the channel system.

This report comprises a handbook for managing western white pine in northern ldaho and western Montana, under the threat of white pine blister rust. Various sections cover the history of the disease and efforts to combat it, the ecology of the white pine and Ribes, alternate host of the rust, and techniques for evaluating the rust hazard and attenuating it. The authors advocate an integrated control strategy based on local stand conditions. Options include planting resistant strains of pine, excising cankers, and chemical, mechanical, and silvicultural control of Ribes.