Treesearch

Variation among habitat associations of 31 riparian bird species in southeastern Wyoming was analyzed using a weighted-means ordination. Three principal components explained 86.7% of the variation among habitat associations of bird species. The components showed high positive loadings for variables associated with canopy, shrub size, and vegetation height.

Budworms (Choristoneura spp.) have repeatedly defoliated millions of hectares of conifers throughout North America. The seriousness of the problem is underscored by research findings in eastern Canada and the northern U.S. Rocky Mountains that the extent, severity, and frequency of bud worm outbreaks have increased in the 20th century, primarily as a result of human-induced changes in forest structure and composition (Blais 1983, Carlson and others 1983, Fellin and others 1983).

A compilation of 11 papers in which authorities discuss the impacts of fire on wildlife habitat and wildlife populations. Presentations cover bobwhite quail, nongame birds, white-tailed deer, bighorn and Stone's sheep; and the response to burning of curlleaf cercocarpus, aspen, evergreen ceanothus, and antelope bitterbrush.

The Fool Creek watershed at the Fraser Experimental Forest, Colorado was harvested using a pattern of alternating clearcut and forested strips in 1956. Today, with almost 30 years of postharvest record, subtle impacts on the hydrology of the watershed can be detected that were not significant in the past. In addition to the depositional increases in the snowpack in the openings, average peak water equivalent over the entire watershed has been increased (9%). Long-term, postharvest, climatic records now available show a strong correlation between estimated increases in flow and winter and...

Seasonal variation in nest site selection by the Abert's towhee (Pipilo aberti) was studied in honey mesquite (Prosopis glandulosa) habitat along the lower Colorado River from March to July, 1981. Stepwise discriminant function analysis identified nest vegetation type, nest direction, and nest height as the three most important variables that characterized the difference between early and late nest sites. Early nests were typically placed low on the southeastern sides of small shrubs or mistletoe, while later nests were built higher in mesquite and mistletoe. Although mesquite was a...

A land-classification system based upon potential natural vegetation is presented for the coniferous forests of central and southern Utah. It is based on reconnaissance sampling of about 720 stands. A hierarchical taxonomic classification of forest sites was developed using the habitat type concept. Seven climax series, 37 habitat types, and six additional phases of habitat types are defined and described. A diagnostic key, using conspicuous indicator species, provides for field identification of the types.

The 1985 National Silviculture Workshop was held in Rapid City, South Dakota, and the Black Hills National Forest. The purpose of the workshop was to discuss, review, and share information and experiences regarding successful silvicultural treatment that may have application in other Regions.

Beetle-killed trees in the Front Range of Colorado were observed for their rate and direction of falling. No trees fell within the 2 years following infestation. Thereafter, trees generally fell at the rate of 3-5% per year unless winds exceeded 75 mph. Most trees fell to the east and broke off between ground level and 2 feet above ground.

The COVER model predicts vertical and horizontal tree canopy closure, tree foliage biomass, and the probability of occurrence, height, and cover of shrubs in forest stands. This paper documents use of the COVER program, an adjunct to the Stand Prognosis Model. Preparation of input, interpretation of output, program control, model characteristics, and example applications are describe.

Dwarf shrews (Sorex nanus), masked shrews (Sorex cinereus), and Merriam shrews (Sorex merriami) were most abundant in riparian and sagebrush-grass habitat types in southeastern Montana. Litter cover was greater in areas occupied by shrews than in areas without shrews. Microhabitat humidity, as related to litter cover and vegetation structure, appears to affect shrew distribution in southeastern Montana.