نتایج جستجو برای: shelterwood
تعداد نتایج: 147 فیلتر نتایج به سال:
The Aleza Lake Shelterwood Case Study is a recent introduction of uniform shelterwood methods to interior spruce-subalpine fir forests in central British Columbia. The goal of this operational trial is to test spruce shelterwood prescriptions designed for local conditions, and to monitor and report on post-harvest silvicultural results. Potential risks and operational disadvantages are also bei...
We propose a spatial aggregation method to solve an optimal harvest scheduling problem for strip shelterwood management. Strip shelterwood management involves either a two-cut system with a preparatory-removal cut cycle, or a three-cut system with a preparatory-establishment-removal cut cycle. In this study we consider these connected sequential cuts as one decision variable, then employ conven...
After more than 50 years of research and selective breeding, blight-resistant American chestnut (Castanea dentata) trees will soon be available for planting into the species’ pre-blight range. Increased understanding of the regeneration requirements of pure American chestnut (C. dentata [Marsh.] Borkh.) will increase the success of future efforts to establish blight-resistant chestnut. We quant...
The ability to restore American chestnut (Castanea dentata) through the planting of blight-resistant (Cryphonectria parasitica) trees is currently being tested. Forest-based research on the species’ silvicultural requirements and chestnut blight development are lacking. Pure American chestnut seedlings were planted in a two-age shelterwood forest with low residual basal area and in a midstory-r...
Results of an 11 yr study of the growth and survival of planted northern red oak (Quercus rubra L.) seedlings (2-0 bare-root) are presented. More than 4,000 seedlings were planted under shelterwood overstories that were harvested 3 yr after planting. Results are expressed as planted-tree dominance probabilities. Dominance probability is the probability that a planted tree will live to attain a ...
The northern flying squirrel (Glaucomys sabrinus) is the primary prey of northern spotted owls (Strix occidentalis caurina) and California spotted owls (S. o. occidentalis) throughout much of the owls' ranges. Flying squirrel abundance patterns, however, are poorly documented. Using capture-recapture techniques to estimate density, we compared flying squirrel densities among 3 types of fir (Abi...
The use of shelterwoods to favour the development of natural or underplanted seedlings is common in temperate forests but rare in the pine forests of the Mediterranean area. Our aim was to assess the use of shelterwoods in Aleppo pine (Pinus halepensis) woodlands in southern France to promote the survival and growth of two co-occurring oak species: the deciduous Quercus pubescens and the evergr...
We compared abundances of seven species of forest rodents among three types of fir (Abies concolor and A. magnifica) forest: unlogged old-growth, unlogged mature, and shelterwood-logged old-growth. Small mammals were livetrapped during summers 1991 and 1992 in four grids within each type of forest; grids were located in the Lassen National Forest in northeastern California. Shelterwood-logged f...
Shortleaf pine (Pinus echinata Mill.) seed production was monitored for 4 yr in stands harvested by a range of evenand uneven-aged reproduction cutting methods. The fifty-two 35–40 ac stands were distributed throughout the Ouachita Mountains from central Arkansas to eastern Oklahoma. Seed crops were characterized as good, poor, poor, and bumper, averaging 109,000, 18,000, 5,000, and 379,000 sou...
Within the Central Rocky Mountains, spruce beetle populations have the potential to rapidly transition from endemic to epidemic levels in the spruce-fir (Engelmann spruce and subalpine fir) forest type. Conventional management has focused on creating resistance to spruce beetle outbreaks by manipulating the overstory density and composition. Three silvicultural treatments, single tree selection...
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