نتایج جستجو برای: forest trees
تعداد نتایج: 184211 فیلتر نتایج به سال:
Determining the exact position of a forest inventory plot—and hence the position of the sampled trees—is often hampered by a poor Global Navigation Satellite System (GNSS) signal quality beneath the forest canopy. Inaccurate geo-references hamper the performance of models that aim to retrieve useful information from spatially high remote sensing data (e.g., species classification or timber volu...
We present two constraints that partition the vertices of an undirected n-vertex, m-edge graph G = (V, E) into a set of vertex-disjoint trees. The first is the resource-forest constraint, where we assume that a subset R ⊆ V of the vertices are resource vertices. The constraint specifies that each tree in the forest must contain at least one resource vertex. This is the natural undirected counte...
diameter is such a notable characteristic in forest inventory that it is important to have a suitablemethod of its measurement, especially in coppice trees. this seems more important in zagros foreststhat most of them are covered with coppice trees. so this research was aimed to find an efficientmethod in studying the diameter at root collar (drc) of persian oak coppice trees as the mostimporta...
lack of forest management plan and forest road network caused that the traditional tree felling and processing was developed in hyrcanian forest. in this system, trees are felled, limbed and topped motor-manually. felled trees are processed with chainsaws into lumber and/or pulpwood. in order to evaluate this system, lumber processing was studied in two compartments of namkhaneh district in khe...
introduction forest ecosystems have continuously downgraded due to every environmental pressure including climate change, aerosols deposits, industrial pollutions and other degradation factors. the output soon or late would be a different forest. forest monitoring is a well-regulated and usually long running procedure, which has the ability to detect these phenomena and reactions based on aims ...
Composition and structure of a three-storied Fagus orientalis-dominated forest was investigated in the Caspian forests, north of Iran. Circular sampling plots of 1000 m2 occupied by advance growth and natural regeneration were randomly chosen where the initial cuttings (with shelterwood aim) were performed. Abundance of species at different growth stages and quality of seedlings and saplings we...
Wind disturbance profoundly shapes temperate forests but few studies have evaluated patterns and mechanisms of long-term forest dynamics following major windthrows. In 1990, we initiated a large hurricane simulation experiment in a 0.8-ha manipulation (pulldown) and 0.6-ha control area of a maturing Quercus rubra--Acer rubrum forest in New England. We toppled 276 trees in the pulldown, using a ...
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