نتایج جستجو برای: zagross forests
تعداد نتایج: 39428 فیلتر نتایج به سال:
گونه petasites albus (l.) gaertner به عنوان گزارش جدیدی از جنگلهای شمال ایران نام برده می شود. این گونه از petasites hybridus (l.) p. gaertner به علت داشتن کرک های دائمی تار عنکبوتی در زیر برگها و گل آذینی بلند و کشیده و گل های سفید رنگ با برگه های گریبانه ای غده دار متفاوت است.
increasing urbanisation and industrialisation have led to a dramatic reduction in forest area, and now only culturally protected remnants of natural forests and some new plantations remain in most areas of the north of iran. to investigate the status of the chemical and physical characteristics of soil under these remnant forests and assess the possible impacts of reforestation on soil properti...
Small and scattered patches of forests contrast sharply within the context flat monotonous dark green pastures in Dutch polder landscapes. These patches, with various types trees, are like little islands, surrounded by ditches. They not remnants original old peat swamp but farmers created past for particular purposes. Their names offer clear indications: addition to general name ‘small forests’...
In the years 2009–2013, China carried out its eighth national survey of forest resources. Based on the survey data, this paper used a biomass conversion function method to evaluate the carbon stores and carbon density of China’s arboreal forests. The results showed that: (1) By age group, the largest portion of carbon stores in China’s arboreal forests are in middle-aged forests. Over-mature fo...
this study aims to investigate the relationships between people?s livelihoods and the woodland resources of the ganaveh watershed in southern zagros, iran, as a basis for suggestions of strategies for sustainable management of the woodland resources and improvement of the livelihoods of people in the community. household data were collected through interviews with heads of households and member...
chestnut-leaved oak (quercus castaneifolia c. a. mey) is one of the most important native oaks of iran distributed in the hyrcanian forests. the pure and mixed stands of it cover about 6.5% of these forests. the species represents morphological variations which have resulted in the description of several infraspecific taxa by different authors. eight taxa were recognized as subspecies and varie...
economic and environmental logging is important for sustainable wood production in the caspian forests, north of iran. predetermination of the skid trail network and directional felling is a usual recommended method to reduce logging impact. the aim of this study was evaluation of directional felling and finding factors effective on felling error. totally 135 trees were selected randomly for di...
Hunting with firearms decimates primates of large and medium body size (>2 kg) that disperse the seeds of large-seeded trees. In continuous, un-fragmented forests of southeastern Peru regularly hunted with firearms for 30–40 years, large primates are extirpated and medium-sized (medium) primates are reduced 61% compared with protected forests. At hunted sites seedlings and small juveniles (<1 m...
Rates and spatial patterns of tree mortality are predicted to change during forest structural development. In young forests, mortality should be primarily density dependent due to competition for light, leading to an increasingly spatially uniform pattern of surviving trees. In contrast, mortality in old-growth forests should be primarily caused by contagious and spatially autocorrelated agents...
In the Great Lakes region, little data exist on the distribution of exotic earthworm species or their relative impacts to soil structure and plant communities in forest types other than those dominated by sugar maple. Our objective was to document the earthworm populations in relation to their proximity to human development (e.g., campgrounds, boat landings, roads) in beech-maple dominated fore...
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