Treesearch

Guidelines are provided to help the forest manager and silviculturist develop even- and/or uneven-aged cutting practices needed to convert old-growth spruce-fir forests into managed stands for a variety of resource needs. Guidelines consider stand conditions, succession, windfall risk, and insect and disease susceptibility. Cutting practices are designed to integrate timber production with increased water yield, maintained water quality, improved wildlife habitat, and enhanced opportunities for recreation and scenic viewing.

Two good, three heavy, and two bumper spruce seed crops were produced during a 15-year period. There was considerable variability in seed crops, however. Not all locations produced good to bumper seed crops when overall yearly ratings averaged good or better; conversely, some locations produced bumper seed crops in 3 or more years. Mathematical relationships, that should be useful in estimating potential sound seed production, were estimated between periodic annual15-year sound seed production and (1) periodic annual15-year total seed production and (2) selected stand parameters of...

Two cultural treatments were evaluated over a 6-year post-treatment period to determine their effect on regeneration of native woodlands in southwestern North Dakota. Cultural treatments included livestock exclusion and the combination of felling and removal of low-vigor trees and transplanting of woody plants. Shrub density varied by species when grazed and ungrazed treatments were compared. American elm (Ulmus americana) increased on grazed areas. Thinning and removal of decadent tree stems stimulated sprout regeneration of green ash (Fraxinum pennsylvanica) and American elm, and...

Ten-year survival and growth of seedlings from 77 parent trees from throughout the Black Hills were compared, using a cluster-analysis technique. Five clusters were identified that account for most of the variability in survival and growth of the open-pollinated families. One cluster, containing 6 families, exhibited exceptional survival and growth. Another, containing 12 families, exhibited poor survival and growth. The performance of families in these two groups appears to be related to location and elevation of parent trees.

Prescribed burning created a more favorable seedbed by exposing mineral soil and increasing soil moisture, resulting in a twenty-fold increase in the number of seeds germinating on burned compared to unburned sites.

Five equation systems are described which can be used to estimate upper stem diameter, total individual tree cubic-foot volume, and merchantable cubic-foot volumes to any merchantability imit (expressed in terms of diameter or height), both inside and outside bark. The equations provide consistent results since they are mathematically related and are fit using stem analysis data from plantation-grown red and loblolly pine. Comparisons are made to determine which equation system provides the best overall fit to a set of validation data for each species. Results indicate that a system based...

A unique selection of antelope bitterbrush (Purshia tridentata [Pursh] DC) recently became the first accession of this valuable western shrub species to be released for commercial seed collection and production. Chosen for its productivity, palatability, winter leafiness, cover value, and seedling vigor, 'Lassen' antelope bitterbrush is a useful shrub for wildlife and livestock ranges, conservation plantings, and reclamation projects on adapted sites in the Intermountain and Pacific Northwest regions.

Four treatments, all combinations of leaving or removing residual trees and shrubs or scarifying or not scarifying seedbeds, were evaluated for species differences in growth, vigor, and expression of dominance. Western larch was the dominant species in regeneration and growth but had begun to lose some of its advantage by age 25, particularly on scarified areas where overstocking commonly occurred. Douglas-fir was less sensitive to the treatments and, although significantly slower in absolute growth than larch, began to accelerate after 15 years of age. This study confirms that early...

A climatic description of the Glacier-Waterton Lakes Park area; mainly covers Glacier. Contains numerous tables, graphs, and maps showing the year-round pattern of climatic elements and 10-day details during fire season. Data analysis includes frequency distributions in addition to average values. Examines relationship of averages to topography, weather correlations between stations, persistence of weather, and climatic trends during this century.

Genetic differentiation of 64 populations from central Idaho was studied in field, greenhouse and laboratory tests. Analyses of variables reflecting growth potential, phenology, morphology, cold hardiness and periodicity of shoot elongation revealed population differentiation for a variety of traits. Regression models related as much as 61 percent of the variance among populations to the elevation and geographic location of the seed source. Clinical patterns of adaptive variation provide the basis for developing seed transfer guidelines that will control maladaptation in reforestation. In...