نتایج جستجو برای: uneven aged stands
تعداد نتایج: 225767 فیلتر نتایج به سال:
Stem number distributions in uneven-aged forests are assumed to be stable, if they follow special functions, e.g. de Liocourt’s reverse J-shaped breast height diameter distribution. These distributions therefore are frequently regarded as a target in all-aged forests. Intending to convert an even-aged forest or any other forest, not yet exhibiting this sort of equilibrium, towards a steady stat...
Reduced frequency of fire in historically fire-adapted ecosystems may have adverse effects on ecosystem structure, function, and resilience. Lack of fire increases stand density and promotes successional replacement of seral dominant trees by late-successional, more shade-tolerant species. These changes are thought to increase competition for limited resources among trees and to increase physio...
Interest in uneven-aged silviculture has increased since advent of ecosystem management programs, which place greater emphasis on ecological values and ecosystem services while also harvesting timber from the forest. However, traditional uneven-aged approaches (e.g., BDq) are often criticized as too complex, costly, and requiring highly-trained staff. The ProportionalB method (Pro-B) addresses ...
Key words Structure was assessed in uneven-aged stands of loblolly (Pinus taeda) and shortleaf pine (P. echinata) that were subjected to prescribed winter burns on cycles of 0, 3, 6, and 9 years. Vegetation assessments were made in late summer of 1990, 10 years after a single hardwood control treatment (basal injection of nonpine woody plants >2.5 cm in ground-line diameter with TordorP 101 R);...
We compiled data from several independent, long-term silvicultural studies on USDA Forest Service experimental forests across a latitudinal gradient in the northeastern and north-central U.S.A. to evaluate factors influencing aboveground live-tree carbon sequestration mortality. Data represent five sites with more than 70,000 repeated tree records spanning eight decades, ecoregions, range of st...
Enhancement of forest growth through silvicultural modification of stand density is one strategy for increasing carbon (C) sequestration. Using the Fire and Fuels Extension of the Forest Vegetation Simulator, the effects of even-aged, uneven-aged and no-action management scenarios on C sequestration in a southern Appalachian red spruce-Fraser fir forest were modeled. We explicitly considered C ...
Logging disturbance is important in uneven-aged stands because harvests are frequent, merchantable trees are retained, and regeneration may be present. Logging disturbance was monitored during the establishment of a study testing the application of uneven-aged silvicufture in an irregularly aged, pine-hardwood stand. Disturbances were: (1) seedbed conditions averaging 56, 16, 9, and 17 percent ...
Periodic regeneration is crucial to creating or sustaining uneven-aged (UEA) stands of loblolly (Pinus tuedu L.) and shortleaf (p echinatu Mill.) pines. Although both species are shade intolerant, they have silvical characteristics that are conducive to natural regeneration in UEA stands. Their seed production is fairly consistent and good, and the wind-disseminated seeds are well dispersed thr...
We describe the application of neural networks adhering to the unsupervised learning paradigm to individual tree mortality prediction within forest growth modeling. The data set used for this study originates from permanent sample plots in uneven-aged Norway spruce (Picea abies L. Karst) stands in Austria. In addition we use the same data set and param-eterise a LOGIT model which represents the...
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