نتایج جستجو برای: diversity of vegetation density

تعداد نتایج: 21214870  

Assessment of forest soil and vegetation characteristics provides basic and essential information for the protection and rehabilitation measures in forest ecosystems. Therefore, regard to the importance of this issue, the distribution of different soil properties and vegetation diversity in relation to conservation management and degradation investigated in the oak forests of Ilam province usin...

2007
Elizabeth A. Allen Robert S. Nowak

As pinyon–juniper (specifically, Pinus monophylla and Juniperus osteosperma) woodlands in the western United States increase in distribution and density, understory growth declines and the occurrence of crown fires increases, leaving mountainsides open to both soil erosion and invasion by exotic species. We examined if the loss in understory cover that occurred with increasing tree cover was re...

2017
Ugo Arbieu Claudia Grünewald Matthias Schleuning Katrin Böhning-Gaese

Southern African protected areas (PAs) harbour a great diversity of animals, which represent a large potential for wildlife tourism. In this region, global change is expected to result in vegetation changes, such as bush encroachment and increases in vegetation density. However, little is known on the influence of vegetation structure on wildlife tourists' wildlife viewing experience and satisf...

Journal: :مرتع و آبخیزداری 0
سیده زهره میردیلمی شناخت مهم ترین تغییر در مؤلفه های کمّی و کیفی پوشش گیاهی بر اثر قرق مراتع دشت کالپوش با استفاده از آنالیز چندمتغیره اسماعیل شیدایی کرکج دانشجوی دکتری علوم مرتع، دانشگاه علوم کشاورزی و منابع طبیعی گرگان موسی اکبرلو دانشیار گروه مرتع داری دانشگاه علوم کشاورزی و منابع طبیعی گرگان

considering the importance of vegetation changes and awareness of its destruction or improvement trends in programming and its proper managing of utilization, this study was conducted in order to survey the effects of grazing on the qualitative and quantitative components of vegetation (including life form, growth form, palatability class, plant families and species diversity) and recognition t...

پایان نامه :وزارت علوم، تحقیقات و فناوری - پژوهشگاه دانشهای بنیادی (مرکز تحقیقات فیزیک نظری و - پژوهشکده علوم نانو 1392

among the low–dimensional allotropes of carbon, nanotubes and graphene have attracted very much attention from nano–science and nanotechnology specialists. they have been proposed as building blocks in nanometer device engineering. however, these structures are not defect–free. in this thesis, we focused on defective carbon nanotubes and graphene, and studied the effect of couple of very common...

In order to investigate the diversity of plant species in forested areas, this study was carried out in forestry near the Khuzestan Steel Industries Company with a total area of 60 hectares in the southeast of Ahwaz, Khuzestan province. For this purpose, 30 plot of 20 × 20 meters in size were systematically randomized in the forested area and 30 samples were taken in the control area. Within ea...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه شیخ بهایی - دانشکده زبانهای خارجی 1391

simplification universal as a universal feature of translation means translated texts tend to use simpler language than original texts in the same language and it can be critically investigated through common concepts: type/token ratio, lexical density, and mean sentence length. although steps have been taken to test this hypothesis in various text types in different linguistic communities, in ...

F Lotfifard, Hassan Zare-maivan, Zahra Tayebi,

Moist and temperate Caspian forests are associated with a diversity of soil types and topography.  Although, natural history and ecological attributes of the Caspian vegetation is well-documented, little is known about mycorrhizae of the Caspian (Hyrcanian) flora. Samples of herbaceous plant species were collected from 4 pre-determined altitudes (-13 upto about 1500m above sea level, appro...

Bita Tangestani, Mani Arman, Parviz Bavarsad,

Moist and temperate Caspian forests are associated with a diversity of soil types and topography.  Although, natural history and ecological attributes of the Caspian vegetation is well-documented, little is known about mycorrhizae of the Caspian (Hyrcanian) flora. Samples of herbaceous plant species were collected from 4 pre-determined altitudes (-13 upto about 1500m above sea level, appro...

In dry lands, semi-circular bund has been considered as a management practice used to restore the ecological revival in terms of vegetation enrichment and soil amelioration. This study was conducted to investigate the effects of semi-circular bunds on vegetation cover and some soil properties in Koteh rangeland, Sistan and Baloochestan province, Iran (2014). Adjacent to the semi-circular bund a...

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