نتایج جستجو برای: forest trees
تعداد نتایج: 184211 فیلتر نتایج به سال:
In many areas, chemical and biological characteristics of soils change when trees colonize meadows. To determine if the invasion of high meadows by forests in the central Cascade Mountains of Oregon altered soil properties, we measured soil properties along transects from mountain meadows through transition zones, where trees were becoming established, into mature forest. The differences observ...
Fire shapes the distribution of savanna and forest through complex interactions involving climate, resources and species traits. Based on data from central Brazil, we propose that these interactions are governed by two critical thresholds. The fire-resistance threshold is reached when individual trees have accumulated sufficient bark to avoid stem death, whereas the fire-suppression threshold i...
Forest roads are the base infrastructure foundation of forestry operations. These roads entail a complex engineering effort because they can cause substantial environmental damage to forests and include a high-cost construction. This study was carried out in four sample sites of Giresun, Trabzon(2) and Artvin Forest Directorate, which is in the Black Sea region of Turkey. The areas have both st...
Forest plots provide an effective means of presenting a wealth of information in a single graphic. Whether used to illustrate multiple results in a single study or the cumulative knowledge of an entire field, forest plots have become an accepted and generally understood way of presenting many estimates simultaneously. This article explores advanced uses of the forest plot with the intent of hig...
Tropical rainforest trees typically occur in low population densities and rely on animals for cross-pollination. It is of conservation interest therefore to understand how rainforest fragmentation may alter the pollination and breeding structure of remnant trees. Previous studies of the Amazonian tree Dinizia excelsa (Fabaceae) found African honeybees (Apis mellifera scutellata) as the predomin...
This paper describes a deterministic computer model for simulating forest dynamics. The model predicts the long-term dynamics of hollow-bearing trees which occur in a single-species (monotypic) forest stand under an array of different timber harvesting regimes over a time scale of centuries. It is applied to a number of different timber harvesting scenarios in the mountain ash (Eucalyptus regna...
the aim of this study was to develop a methodology to identify suitable habitat of the eurasian nuthatch (sitta europea) at kheyrood forest, northern alborz, iran. this study was carried out during spring to summer 2008. with attention to the area and topographic condition of kheyrood forest, patom, namkhane, gorazbon, cheler and baharbon were selected as data collecting series. the present stu...
Forest restoration is an increasingly important tool to offset and indeed reverse global deforestation rates. One low cost strategy to accelerate forest recovery is conserving scattered native trees that persist across disturbed landscapes and which may act as seedling recruitment foci. Ficus trees, which are considered to be critically important components of tropical ecosystems, may be partic...
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