Treesearch

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.

Relationships for predicting duff reduction, mineral soil exposure, and consumption of downed woody fuel were determined to assist in planning prescribed fires. Independent variables included lower and entire duff moisture contents, loadings of downed woody fuels, duff depth, National Fire-Danger Rating System 1,000-hour moisture content, and Canadian Duff Moisture Codes. Results apply to a number of mesic forest cover types.

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.

This paper reports methodology for investigating recreation choice behavior using grounded, naturalistic research methods. How these techniques can be coordinated with other social research methods is described. Naturalistic methods are preferred over other approaches to uncover recreationists' decision making processes at work.

The State of Montana, in cooperation with the U.S. Forest Service and Bonneville Power Administration, is conducting a five-vear study on the impacts of a 500-kV transmission line on elk habitat and hunter opportunity. In fall 1983, baseline data on hunting patterns and quality were collected from over 600 hunters interviewed in three western Montana study areas. A cluster analysis revealed seven types of hunters, each of which should be affected differently by the transmission line impacts. Hypotheses developed will be tested during two subsequent hunter surveys in 1985 and 1986.

Substitutes become an issue when people are constrained from participating in desired activities. This study investigates and compares activity and resource substitutes for recreational salmon fishing in New Zealand. Results suggest that resource substitution and inventories need more attention, user perceptions of substitutes are important, substitutes can be asymmetrical, activity substitutes may be hard to find, and substitutability studies need to be integrated with availability studies.