نتایج جستجو برای: forest density

تعداد نتایج: 509797  

Journal: :محیط شناسی 0
محمد جواد امیری دانشجوی دکترای جنگلداری دانشگاه تربیت مدرس نور سید غلامعلی جلالی دانشیار گروه جنگلداری دانشکدة منابع طبیعی دانشگاه تربیت مدرس نور عبدالرسول سلمان ماهینی استادیار دانشکدة محیط زیست دانشگاه علوم کشاورزی و منابع طبیعی گرگان سید محسن حسینی دانشیار گروه جنگلداری دانشکدة منابع طبیعی دانشگاه تربیت مدرس نور فرود آذری دهکردی استادیار گروه برنامه ریزی و مدیریت دانشکدة محیط زیست دانشگاه تهران

forest ecosystems that have spent a long time to mature, offer important goods and services to humanity. hence, utilization and exploitation of these resources should be based on careful assessment of their ecological value and potential. ecological land evaluation is an approach based on land quality, vulnerability and potential assessment for different acceptable uses drawing upon related mod...

ژورنال: علوم آب و خاک 2011
سمیه شمسی محمودآبادی, , فرهاد خرمالی, ,

In order to study the effects of different land uses on soil development, a loess hillslope was selected in Agh-Su area, eastern Golestan Province. Six profiles in four land uses including pasture, Quercuse natural forest, Cupressus artificial forest and a cultivated land, were dug and studied. Samples from different horizons were collected for physico-chemical and microscopic analyses. Importa...

2015
Oyomoare L. Osazuwa-Peters Colin A. Chapman Amy E. Zanne

Selective logging of tropical forests is increasing in extent and intensity. The duration over which impacts of selective logging persist, however, remains an unresolved question, particularly for African forests. Here, we investigate the extent to which a past selective logging event continues to leave its imprint on different components of an East African forest 45 years later. We inventoried...

Journal: :caspian journal of environmental sciences 2010
r. akhavan

estimating the amount of variation due to spatial dependence at different scales provides a basis for designing effective experiments. accurate knowledge of spatial structures is needed to inform silvicultural guidelines and management decisions for long term sustainability of forests. furthermore, geostatistics is a useful tool to describe and draw map the spatial variability and estimation of...

2013
Barry Tyler Wilson Christopher W Woodall Douglas M Griffith

The U.S. has been providing national-scale estimates of forest carbon (C) stocks and stock change to meet United Nations Framework Convention on Climate Change (UNFCCC) reporting requirements for years. Although these currently are provided as national estimates by pool and year to meet greenhouse gas monitoring requirements, there is growing need to disaggregate these estimates to finer scales...

حسین حیدری, رضا, غلامی, محبوبه, معصومی, سید محمد,

The nearest individual method (NIM), Nearest neighbor method (NNM) and compound method (CM) are distance sampling methods that are being applied to measure the plant density (numbers of individuals per unit area). Density is one of the essential structural characteristics in forest stands and useful to understand the dynamics of the forest. The present study aimed to find the most adaptable dis...

2012
Dryw A. Jones Kevin L. O’Hara

Carbon sequestration is an emerging forest management objective within California and around the world. With the passage of the California’s Global Warming Solutions Act (AB32) our need to understand the dynamics of carbon sequestration and to accurately measure carbon storage is essential to insure successful implementation of carbon credit projects throughout the State. As the leader in fores...

Maziar Haidari Nabiollah Yarali Naghi Shabanian

For maintaining of Zagros forests role in wild life, water and soil conservation, the suitable solutions and methods for assessing the existing conditions and planning for management of this forests should be given. To detection of suitable sampling method to study tree Diameter at Breath Height in the northern Zagros forest, Blake forest, in Baneeh region, Kurdistan province, and west of Iran ...

Journal: :جنگل و فرآورده های چوب 0
جواد اسحاقی راد دانشیار گروه جنگل داری دانشکدۀ منابع طبیعی دانشگاه ارومیه، ارومیه، ایران آمنه خانعلیزاده دانشجوی دکتری جنگل داری، دانشکدۀ منابع طبیعی دانشگاه ارومیه، ارومیه، ایران

this study was performed in order to investigate the changes in vegetation and soil properties in compartment no.317 (managed forest) and no.318 (control forest) of jamand district of golband forest in mazandaran (noshahr). for this purpose, random-systematic sampling method with regular grid of 100×200 m was used to locate samples. the plot size was 400 m2 considering to tree and shrub species...

Journal: :The Journal of animal ecology 2009
David N M Mbora Mark A McPeek

1. Habitat loss and fragmentation are the principal causes of the loss of biological diversity. In addition, parasitic diseases are an emerging threat to many animals. Nevertheless, relatively few studies have tested how habitat loss and fragmentation influence the prevalence and richness of parasites in animals. 2. Several studies of nonhuman primates have shown that measures of human activity...

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