Treesearch

A land-classification system based upon potential natural vegetation is presented for the forests of Montana. It is based on an intensive 4-year study and reconnaissance sampling of about 1,500 stands. A hierarchical classification of forest sites was developed using the habitat type concept. A total of 9 climax series, 64 habitat types, and 37 additional phases of habitat types are defined. A diagnostic key is provided for field identification of the types based on indicator species used in development of the classification. More Information

Nitrogen and phosphorus fertilizers were applied to the soil surface in a 2-0 ponderosa pine plantation on the Payette National Forest in west-central Idaho. The study area was located in an Abies grandis/Acer glabrum habitat type on a basalt soil. The fertilizer treatments did not increase survival or growth of the trees, nor did they increase the amount of competing vegetation. The only significant response was a reduction in survival caused by the high level nitrogen treatments.

The 1978 National Fire-Danger Rating System (NFDRS) updates the danger rating system developed in the early 1970's and published by Deeming and others in 1972. Numerous changes have been made to correct deficiencies and to incorporate new technology. The results of this work are presented in two publications. This publication covers the general information on the NFDRS and its application; a second publication (Burgan and others 1977) contains the nomograms and directions for calculating fire-danger ratings manually.

Natural regeneration success of Engelmann spruce in clearcut openings, with adequate seed, is controlled by weather and aspect and modified by seedbed conditions. Small clearcut openings of 1-2 hectares can be successfully regenerated on north exposures with mineral soil seedbeds and shade. However, successful natural regeneration in openings on south aspects is not possible, and shade is absolutely essential for any survival. Drought was the most serious cause of mortality, but significant losses also resulted from heat girdle, frost heaving, and clipping by birds.

Several rating systems have been proposed to describe the intensity of dwarf mistletoe infection in individual trees or stands, but the 6-class dwarf mistletoe rating (DMR) system, described in 1956, has been most widely adopted. This system is being used for several dwarf mistletoe host/parasite combinations in western North America. Uses and limitations of the 6-class system are discussed, and several applications of the system are cited.

Cattle and mule deer competed very little for forage on a central Colorado ponderosa pine-bunchgrass range during the spring-summer-fall grazing season. Species they selected for the bulk of their diets were quite different. Diets overlapped most for fringed sagebrush and sunsedge. Fringed sagebrush was used heavily by both deer and cattle in April-May. Sunsedge was cnsumed in small amounts by both animals throughout most of the grazing season. Management of the timber stand increased forage for both types of animals. Also, timber stand improvement practices resulted in short-term availabil...

Topics discussed include: (1) cutting methods, (2) stand structure goals, which involve choosing a residual stocking level, selecting a maximum tree size, and establishing a diameter distribution using the "q" technique, and (3) harvesting and removal of trees. Examples illustrate how to determine realistic stand structures for the initial entry for specific stand conditions, and management and silvicultural constraints.

The role of deer and cattle in the failure of aspen stands to regenerate on Beaver Mountain in southern Utah was investigated by a series of exclosures constructed in 1934. Three-fourths of each exclosure was clearcut of aspen in 1934. Aspen reproduction, shrubs, and herbaceous understory were measured in 1937, 1942, 1949, and 1975. Implications of wildlife and livestock use on aspen reproduction are discussed.

Summary tables are presented for aboveground biomass and nutrient concentrations for 20 aspen trees (Populus tremuloides Michx.) that were sampled at two study sites in Utah and Wyoming. Trees were divided into seven components - leaves, current twigs, old twigs, deadwood (branches), branches, bark, and bole wood. Samples from each component were analyzed for nitrogen, phosphorus, potassium, calcium, sodium, magnesium, zinc, iron, and percent ash.

Twelve presented and 15 contributed papers highlight what is known about this unique, diminishing vegetative type: characteristics, classification systems, associated fauna, use conflicts, management alternatives, and research needs. Speakers stressed the continuity and interrelationships of riparian ecosystems, their wildlife and vegetation, historic and current uses.