نتایج جستجو برای: mean of diversity shannon

تعداد نتایج: 21194359  

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه فردوسی مشهد - دانشکده علوم 1377

chapters 1 and 2 establish the basic theory of amenability of topological groups and amenability of banach algebras. also we prove that. if g is a topological group, then r (wluc (g)) (resp. r (luc (g))) if and only if there exists a mean m on wluc (g) (resp. luc (g)) such that for every wluc (g) (resp. every luc (g)) and every element d of a dense subset d od g, m (r)m (f) holds. chapter 3 inv...

2017
Wang Tian Huayong Zhang Lei Zhao Feifan Zhang Hai Huang

The relationship between biodiversity and ecosystem functioning is a central issue in ecology, but how this relationship is affected by nutrient stress is still unknown. In this study, we analyzed the phytoplankton diversity effects on community biomass and stability along nutrient gradients in an artificial eutrophic lake. Four nutrient gradients, varying from slightly eutrophic to highly eutr...

جعفری, فرهنگ , زارع‌کیا, صدیقه, غلامی, پرویز , فیاض, محمد, گودرزی, محمود ,

Livestock grazing is a common human-induced activity with direct and indirect effects even on the ecosystems of protected areas. The present study analyzed the effects of different grazing management methods on species diversity and richness in the steppe rangelands of Saveh, Iran. Data were collected from sixty 2×2 m plots within the areas of three, four-years protected range management projec...

Journal: :journal of rangeland science 0
mohsen sharafatmandrad natural resources department, rangeland and watershed management section, university of jiroft, jiroft, iran hossein naderi faculty of rangeland and watershed management, gorgan university of agricultural sciences and natural resources

biodiversity plays a crucial role in stability and productivity of natural ecosystem. the main goal of this research was to classify ecological groups in steppe rangeland and investigate their relationships with plant diversity indices. therefore, fifty different land unit tracts (lut) were identified in khod-neuk basin, yazd province, iran, in 2010. vegetation and soil samples were taken in th...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه تربیت مدرس - دانشکده منابع طبیعی و علوم دریایی 1388

this research was conducted in two protect and destroy region in the middle zagros, in illam province. in order to identification of ecological species group and evaluate density of regeneration, effect of many factors such as protection, vegetation, physiographic factors, physical and chemical properties of soil in study locations were studied. to achieve these purpose number of 54 plots using...

al. et M. Sharifinia

The distribution of macroinvertebrate communities from 5 sampling sites of the Tajan River were used to examine the relationship among physiochemical parameters with macroinvertebrate communities and also to assess ecological classification system as a tool for the management and conservation purposes. The amount of variation explained in macroinvertebrate taxa composition is within values r...

Journal: :پژوهش های زراعی ایران 0
علیرضا کوچکی مهدی نصیری محلاتی سارا سنجانی

in order to investigate the weed diversity and modeling light interception in sole and intercropping millet and bean an experiment was conducted as complete randomized block design with 4 treatments and 4 replications at the agricultural research station, ferdowsi university of mashhad, iran, during 2008. treatments included monocultures, intercropping of millet and bean and a control treatment...

Sorghum is the fifth degree of importance in the production of cereal after wheat, rice, maize and barley. Genetic diversity estimation of plant material is primary step for identification, protection and conservation of germplasm and breeding programs designing. In order to study of genetic diversity among 10 genotypes of grain sorghum, 10 microsatellite primers were used according to previous...

ژورنال: مرتع 2020
Erfanzadeh, Reza, Ghelichnia, Hasan, Hadinajad, Mahboobeh,

Soil seed bank can facilitate natural regeneration of rangeland ecosystems. This bank is usually influenced by local plant species. This study was conducted to investigate the effect of canopy cover of three shrubs (Amygdalus scoparia, Daphne mezereum and Ebenus stellata) on the diversity and richness of soil seed bank under their canopies in Chenarnaz rangelands, Khatam city, Yazd province. Fi...

Biodiversity plays a crucial role in stability and productivity of natural ecosystem. The main goal of this research was to classify ecological groups in steppe rangeland and investigate their relationships with plant diversity indices. Therefore, fifty different Land Unit Tracts (LUT) were identified in Khod-Neuk basin, Yazd province, Iran, in 2010. Vegetation and soil samples were taken in th...

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