نتایج جستجو برای: northern zagros forest

تعداد نتایج: 214446  

حجتی, سید محمد, میرزایی زاده, وحید, نیک نژاد, مریم,

In order to map the forest canopy density Bivareh Ilam Landsat 8 satellite data of 22 July 2014 and FCD model was used. The FCD of four indicators of vegetation, soil, shade and the heat index by applying a suitable threshold was and the density of vegetation and forest canopy density map based on FCD in percent respectively. Forest density map obtained, according to the classes provided by the...

Journal: :جنگل و فرآورده های چوب 0
مریم مرادنژادی دانشجوی کارشناسی ‏ ارشد مهندسی جنگل، دانشکدة منابع طبیعی دانشگاه تهران، کرج، ایران مقداد جورغلامی دانشیار گروه جنگل داری و اقتصاد جنگل، دانشکدة منابع طبیعی دانشگاه تهران، کرج، ایران آرش ملکیان استادیار گروه احیای مناطق خشک و کوهستانی، دانشکدة منابع طبیعی دانشگاه تهران، کرج، ایران

forest cover is one of the most effective factors in reducing flooding in northern iran, so that in recent years the destruction, land use changing and uncontrolled harvesting of forest areas, has greatly increased the number and magnitude of floods. so far, there have been few studies on forest hydrology in iran, particularly the northern hyrcanian forests. this study examines the impact of a ...

2016
Matthew B. Russell Christopher W. Woodall Kevin M. Potter Brian F. Walters Grant M. Domke Christopher M. Oswalt

Forest understories across the northern United States (US) are a complex of tree seedlings, endemic forbs, herbs, shrubs, and introduced plant species within a forest structure defined by tree and forest floor attributes. The substantial increase in white-tailed deer (Odocoileus virginianus Zimmerman) populations over the past decades has resulted in heavy browse pressure in many of these fores...

Journal: :journal of sciences islamic republic of iran 0

a totall of 500 early permian samples from the chal-i-sheh formation in the zagros basin were examined palynollogically in order to determine the stratigraphical age of the formation and to assess the palaeogeopaphicd relatianships of this basin to the southern and northern hemispheres during the early permian. fifty-eight taxa were recorded including 46 pollen, 10 spore and 2 acritarch species...

جعفرزاده, علی اکبر, مهدوی, علی, میرزایی زاده, وحید, کرمشاهی, عبدالعلی,

In order to optimize the planning and management of natural resources and the environment, it is essential to know the status of land cover changes over the past decades. Modeling land cover change can provide valuable information for better understanding of this process, determining of effective factors and forecasting of regions subject to change. This study aimed to determine and simulate th...

Journal: :Annals of botany 2003
R M M Crawford C E Jeffree W G Rees

Examination of temperature variations over the past century for Europe and the Arctic from northern Norway to Siberia suggests that variations in the North Atlantic Oscillation are associated with an increase in oceanicity in certain maritime regions. A southward depression of the tree line in favour of wet heaths, bogs and wetland tundra communities is also observed in northern oceanic environ...

Journal: :caspian journal of environmental sciences 2013
p. panahi m. pourhashemi m. zandebasiri

acorn production plays a fundamental role in the organization and dynamics of oak forest ecosystems. regarding acorn importance, visual survey methods have been used to estimate acorn production of oak species throughout the world. in this study, the mast indices of brant`s oak (quercus brantii lindl.) were determined in a section of northern zagros forests, almost 36 ha area, near baneh, kurdi...

Numerical and parametrical indices are two of the most important and most widely used indices for assessing biodiversity in different societies. Nevertheless, their efficiency and selection in various ecosystems has always been one of the challenging issues of ecology. In this study, the numerical indices of diversity, richness and eveness, as well as abundance–ranking distribution models inclu...

2011
John W. Williams Pavel Tarasov Simon Brewer Michael Notaro

[1] Accurate land cover reconstructions are essential to understanding the past and present biogeochemical and biogeophysical interactions between the land surface and atmosphere and the impacts of these interactions on climate. Here we quantitatively reconstruct late Quaternary shifts in woody cover across the Northern Hemisphere forest‐tundra ecotone, based on a synthesis of Northern Hemisphe...

2010
Alireza Salehi Ljusk Ola Eriksson

This study aims to present a diameter class model to predict the effects of different forest management practices on growth and yield conditions of the mixed coppice stands of Persian oak (Quercus persica) in the semiarid forests in southern Zagros, Iran. Using inventory data the model was applied to make management recommendations for a forested watershed. Some requested data for the model wer...

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