Treesearch

Water yield from forest and rangelands can be augmented by managing vegetation and snow to reduce evapotranspiration. Some arbitrary goals to increase water yield were chosen to illustrate the potential for increasing water yield, and treatments were hypothesized to get these increases.

A procedure was developed for surveying cross sections using a sag tape with unequal end elevations. The procedure is as accurate as traditional engineer's level surveys, is faster and easier, and can be programed for a digital computer by following the flow diagram which is provided.

Describes a theoretical model for calculating thermochemical properties of the gaseous fuel that burns in the free flame at the edge of a spreading fire in fine forest fuels. Predicted properties are the heat of combustion, stoichiometric air/fuel mass ratio, mass-averaged temperature, and mass fraction of unburned fuel in the gas mixture emitted from the flame-producing zone. These variables depend upon readily determined intrinsic properties of the fuel, the fuel moisture content, fuel particle surface/volume ratio, particle mass density, and fuel loading. Numerical examples are given...

Nutrient levels as a result of experimental clearcutting, shelterwood cutting, and group selection cutting - each with three levels of harvesting intensity - were studied in a larchfir forest in northwest Montana, experimentally logged with a skyline system. None of the treatments altered nutrient levels in an intermittent stream, nor were excessive amounts of nutrients lost in soil below the root zone. Under conditions on this site, skyline logging did not result in surface erosion or nutrient losses that would affect forest management.

Timber harvesting has a pronounced effect on the soil microflora by wood removal and changing properties. This paper gives a perspective on soil biology-harvesting relationships with emphasis on the northern Rocky Mountain region. Of special significance to forest management operations are the effects of soil micro-organisms on: the availability of soil nutrients, particularly nitrogen; the decay of woody plant material; and tree disease incidence. At present, no widespread detrimental impact on site quality in the northern Rocky Mountain region can be directly attributed to harvesting...

This paper illustrates how much, how long it takes, and the method in which young western larch responds to snow bend. A 13-year-old vigorous larch stand was flattened by a heavy, wet snow in June 1966 in northwestern Montana. We recorded photographically how two different crown classes (dominant and nondominant) of young larch subjected to four levels of snow beud (slight to severe) recuperated during the 11-year period following damage. The vigorous condition of the supple young larch contributed greatly to their remarkable recover.

Growth, phenology and frost tolerance of seedlings from 50 populations of Douglas-fir (Pseudotsuga menziesii var. glauca) were compared in 12 environments. Statistical analyses of six variables (bud burst, bud set, 3-year height, spring and fall frost injuries, and deviation from regression of 3-year height on 2-year height) showed that populations not only differed in mean performance, but also reacted differently to the environmental gradient. Most of the population environment interaction was attributable to heterogeneous regressions of population means on environmental means. For all...

Reports and evaluates the significance of weather conditions and logging activities on elk distribution. Recommendations for reducing the effects of disturbance on elk are presented.

Discusses both the historic and contemporary influences of economic in formulating USDA, Forest Service fire management policy in allocating money for fire management and in appraising fire effects. Includes a partial listing of publications that deal with resource valuation.

Thirty prescribed burns were attempted in pinyon-juniper woodlands from fall 1974 to fall 1976. These attempts were made out of fire season, during varied atmospheric conditions, and in several pinyon-juniper communities. An analysis of the successful burns provided us with a method for predicting burning success from windspeed, air temperature, and vegetation cover. An igniting technique is also discussed.