نتایج جستجو برای: mixed and natural stands
تعداد نتایج: 16917246 فیلتر نتایج به سال:
—Past management practices have changed much of the native mixed pinehardwood forests on upland alluvial terraces of the western Gulf Coastal Plain to either pine monocultures or hardwood (angiosperm) stands. Changes in dominant tree species can alter soil chemical, biological, and physical properties and processes, thereby changing soil attributes, and ultimately, soil functions. Restoring the...
Trembling aspen (Populus tremuloides Michx.) generally grows as clones in which stems, ranging from many thousands to only a few, are interconnected by a common root system. When clones are very large, in one recorded case involving about 47␣ 000 stems joined together over a 43 ha area, aspen becomes a candidate for earth’s most massive and oldest organism. Recent analyses suggest that aspen cl...
Different functions, each in the form of a modified Weibull cumulative distribution function (cdf), were joined together to form a segmented cdfto approximate diameter distributions in forest stands. Estimates of five percentile points (the 0th, 25th, 50th, 75th, and 100th percentiles) were used to determine a segmented cdf. The segmented cdf and the Weibull distribution were fit to diameter da...
The article provides an analysis of changes in the areas Norway maple stands forests Republic Tatarstan from 1944 to 2019. According accounting data forest fund as 01.01.2020, area occupied by is 29.3 thousand hectares (2.5 % area), including 5.0 young growth 1st and 2nd age class, 21.4 middle-aged trees, 1.9 ripening trees 1.0 ripe trees. A reliable relationship was revealed between a decrease...
Log prices can vary significantly by grade: grade 1 logs are often several times the price per unit of grade 3 logs. Because tree grading rules derive from log grading rules, a model that predicts tree grades based on tree and stand-level variables might be useful for predicting stand values. The model could then assist in the modeling of timber supply and in economic optimization. Grade models...
Fire in the boreal region is the dominant agent of forest disturbance with direct impacts on ecosystem structure, carbon cycling, and global climate. Global and biome-scale impacts are mediated by burn severity, measured as loss of forest canopy and consumption of the soil organic layer. To date, knowledge of the spatial variability in burn severity has been limited by sparse field sampling and...
Post-harvest recovery of biodiversity is one important goals in modern forestry. A variable retention (VR) approach has been particular interest North America because it promotes rapid faunal recovery, while minimizing negative lasting impacts logging on the natural fauna. We studied responses rove beetles (Coleoptera: Staphylinidae) to a broad range harvests (2, 10, 20, 50 and 75% retention) c...
—Shortleaf pine (Pinus echinata Mill.) is the only naturally-occurring pine distributed throughout the Ozark-Ouachita Highlands. Once dominant on south-facing and ridgetop stands and important in mixed stands, it is now restricted to southand southwestfacing slopes in the Ouachita and southern Ozark Mountains, and to isolated pure and mixed stands in the northern Ozarks. Its position as a minor...
Whereas there is evidence that mixed-species approaches to production forestry in general can provide positive outcomes relative to monocultures, it is less clear to what extent multiple benefits can be derived from specific mixed-species alternatives. To provide such insights requires evaluations of an encompassing suite of ecosystem services, biodiversity, and forest management considerations...
this study aims at assessing the impact of land use change (from forest areas to forest parks) on some silvicultural characteristics of stands under recreational land use in boloran natural forest park, kuhdasht. for this purpose, three zones including non-recreation, extensive recreation and intensive recreation regions were chosen. in each zone 30 sample plots in a systematic random design (1...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید