نتایج جستجو برای: simpson diversity

تعداد نتایج: 191705  

This study was carried out in managed and unmanaged Fagus orientalis L. (beech) stands in the Asalem beech forest in order to compare the composition and diversity of plant species. Three V-shaped catena landforms were selected for each stand. Then, large quadrats, 400 m2 area, with selective method and within each of them, small quadrats, 4 m2 area, were established along each catena and slope...

Forestry plans have been influential on tree species and planting in different ways, regulating tree species diversity. Investigation of the changes in tree species diversity and preservation livestock sustainability by using forestry inventory can be an appropriate tool for decision makers in management. Indicators such as the Shannon Wiener and Simpson indices can be used to study the variati...

2015
Branko Stajic

The tree species diversity in mixed stands of beech and valuable broadleaves was researched in the area of the National Park `Djerdap` on fifteen sample plots (total study area of about 5 ha). For this purpose, the following diversity measures were applied: (1) Shannon`s index H', (2) Simpson`s index (Simpson 1949), (3) McIntosh`s diversity index D' (McIntosh 1967), (4) Hill’s N1 diversity numb...

Forest degradation influences ecosystem sustainability and reduces plant species diversity. Plantations with coniferous trees in degraded ecosystems help the native species to become established and play a major role in preserving and improving plant diversity. This study aims at measuring and comparing the woody species diversity across different age classes of Pinus brutia and Cupressus horiz...

Journal: :international journal of advanced biological and biomedical research 2013
hamid ahani hamid jalilvand

forests are biologically diverse systems, representing some of the richest biological areas on earth. they offer a variety of habitats for plants, animals and micro-organisms. however, forest biodiversity is increasingly threatened as a result of deforestation, fragmentation, climate change and other stressors. biodiversity is the variation of life forms within a given ecosystem, biome, or on t...

Hamid Ahani, Hamid Jalilvand

Forests are biologically diverse systems, representing some of the richest biological areas on Earth. They offer a variety of habitats for plants, animals and micro-organisms. However, forest biodiversity is increasingly threatened as a result of deforestation, fragmentation, climate change and other stressors. Biodiversity is the variation of life forms within a given ecosystem, biome, or on t...

Hamid Ahani, Hamid Jalilvand

Forests are biologically diverse systems, representing some of the richest biological areas on Earth. They offer a variety of habitats for plants, animals and micro-organisms. However, forest biodiversity is increasingly threatened as a result of deforestation, fragmentation, climate change and other stressors. Biodiversity is the variation of life forms within a given ecosystem, biome, or on t...

Hamid Ahani, Hamid Jalilvand

Forests are biologically diverse systems, representing some of the richest biological areas on Earth. They offer a variety of habitats for plants, animals and micro-organisms. However, forest biodiversity is increasingly threatened as a result of deforestation, fragmentation, climate change and other stressors. Biodiversity is the variation of life forms within a given ecosystem, biome, or on t...

اسحاقی راد, جواد , خانعلیزاده, آمنه ,

The aim of present study was comparison of plant diversity in managed and control compartments of Jamand district in Noshahr (Mazandaran province). Random-systematic sampling method with network dimension of 100×200 m was used to locate samples. Sampling plot area was 400 m2 to survey woody species and 100 m2 plots was set up to herbaceous species (in the center of main plots). At each sample p...

Journal: :محیط زیست طبیعی 0
ساره حسینی دانشجوی دکتری جنگلداری دانشکده منابع طبیعی، دانشگاه علوم کشاورزی و منابع طبیعی ساری سید عطاء اله حسینی دانشیار گروه جنگلدای و اقتصاد جنگل دانشگاه تهران

in this study, species richness, evenness and vegetation biodiversity were investigated in stabilized and non-stabilized cut edge areas of chachkam district forest roads in sari forest of iran. 18 micro plots 1×1m (36 micro plots) were sampled to carry out this research on two cut edge areas. number of trees, shrubs and herbaceous were recorded in each micro-plot. significant difference was inv...

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