Treesearch

From 1965 to 1978, mountain pine beetles killed 25% of the pines taller than 4.5 feet in a study area in north-central Colorado. Average basal area was reduced from 92 to 58 square feet per acre. Mortality increased with tree diameter up to about 9 inches d.b.h. Larger trees appeared to be killed at random. Mortality was directly related to number of trees per acre and presence of dwarf mistletoe, but not to site index, elevation, and percent Douglas-fir in the stand.

Damage to shelterwood leave trees and to understory trees in shelterwood and clearcut logging units logged with skyline yarders was measured, and related to stand conditions, harvesting specifications, and yarding system-terrain interactions. About 23 percent of the marked leave trees in the shelterwood units were killed in logging, and about 10 percent had moderate to serious damage. About 40 percent of the understory trees ·were killed. Heaviest damage in shelterwood was associated with steeper slopes, more trees per acre, and cross-slope angle to the skyline. Understory damage was...

The important properties contributed to forest soils by decayed wood in the Northern Rocky Mountains make it desirable to determine the time required to reconstitute such materials in depleted soils. The ratio of fiber production potential (growth) to total quantity of wood in a steady state ecosystem provides estimates varying from approximately 100 to 300 years, depending on habitat type, for replacement of decayed soil wood. Radiocarbon dating of decayed wood in various stages of incorporation into the soil ranged from 100 to 550 years, depending on site and depth in soil. Species...

A simulation of white pine blister rust is described in both word and mathematical models. The objective of this first generation simulation was to organize and analyze the available epidemiological knowledge to produce a foundation for integrated management of this destructive rust of 5-needle pines. Verification procedures and additional research needs are also discussed.

Biomass determinations in singleleaf pinyon (Pinus monophylla) - Utah juniper (Juniperus osteosperma) stands in Nevada indicate that stem diameter and average crown diameter are the tree measurements most highly correlated with ovendry weights. The equations and tables developed provide a means for estimating the total aboveground biomass as well as the weights for the various size fractions by species. The tables can also be used to estimate the cordwood and slash resulting from fuelwood harvesting operations.

Potential production of ponderosa pine in the Black Hills is simulated for various combinations of stand density, site index, age, and thinning schedule. Such estimates are needed to project future development of stands managed in different ways for various uses.

Reports the Proceedings of a symposium held in Missoula, Mont., Nov. 28-30, 1979. Research involved investigation of alternative timber harvesting and processing practices that can achieve more intensive timber utilization.

Present concern for the potential impacts land use activities can have on the water resource has prompted an increased interest in evaluating the effects of forest management practices on Water yield and quality. The most widespread water quality problem associated with forest management and in particular silviculture and related road construction activities is accelerated site erosion with subsequent increased sedimentation of freshwater streams and lakes.

The purpose of this study was to assess the composite land use effects on water quality on a diversely developed tributary to the South Platte River in the Colorado Front Range. Data were collected over a two-year period to assess impacts of mountain home development, grazing and lake-based recreation on suspended solids, specific conductance, total dissolved solids, nitrate, chloride, fecal coliform and fecal streptococcal bacteria. Four specific treatment areas were evaluated for both their local and composite impact on the selected constituents. Treatments included grazing, road-fill...

This report contains edited and reviewed versions of papers presented at a workshop held at the University of Vermont in April 1980. Topics include sampling avian habitats, multivariate methods, applications, examples, and new approaches to analysis and interpretation.