نتایج جستجو برای: forest species changing
تعداد نتایج: 771031 فیلتر نتایج به سال:
Natural regeneration ensures the survival of forest stands and sustainable forest development. The present study was conducted to investigate the natural regeneration of Persian oak (Quercus macranthera fisch. & C.A.Mey. Ex Hohen) stands in Arasbaran protected forest. Measurement of the frequency of standard and coppice regenerations was carried out in one-hectare square plots (100 × 100 m) in ...
Tree marking can cause changes in forest. This study aimed to assess tree marking operation and to predict its effect on stand structure of Persian ironwood-hornbeam stands at Bahramnia forestry plan, north of Iran. Therefore 98 trees that were marked in compartment 9 of the mentioned forest in 2017 based on selection system and according to the recent laws of Forests, Range and Watershed Manag...
Douglas-fir forests in the interior Pacific Northwest are subject to sporadic outbreaks of the western spruce budworm, a species widely recognized as the most destructive defoliator in western North Amer-ica. Outbreaks of the western spruce budworm often occur synchronously over broad regions and lead to widespread loss of leaf area and decrease in growth rates in affected stands. In spite of t...
Species in the genus Castanea Mill. are one of the worthwhile species in the Hyrcanian forest of west Guilan (N Iran) with low region such as Siahmazgi, Ghalerodkhan and Visrod. that do not have good condition by reason of human interfering and disease. They have varying economic importance as nut tree crops, therefore, DNA barcoding technique can be a straightforward method for taxonomic statu...
Protection aspects are important in Zagros Forest because degradation and soil erosion is an important problem in this area. Consequently, the responsible organizations use needle-leaf species for forest restoration. The object of this study was investigation effect of exotics needle-leaves plantation on soil quality and compare with natural soil forest in Garan research station in Marivan. In ...
The key factor in understanding the forest ecosystems is forest structure. Spatial arrangement and location of trees are both one of the main components of forest stand structure. This study was carried out in Manesht protected area, Ilam province. In order to determine the ecological groups and spatial patterns of indicator species, we used fixed-area plots method. For data collection, 125 squ...
Palaeoecological evidence is used to investigate climatic and anthropogenic drivers of vegetation and fire dynamics through the past ~1200 years in the Eastern Arc Mountains, Tanzania. Pollen and charcoal analyses are supported by a chronology derived from five accelerator mass spectrometry ages, a 137Cs activity profile and marker horizons from two exotic pollen taxa. Pollen indicator taxa are...
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