نتایج جستجو برای: all sorts of diversity indices

تعداد نتایج: 21215650  

Journal: :Biosystems Diversity 2023

The article evaluates the dependence of most common indices species diversity on sample size and determines their ability to differentiate between different types ecosystems, with a special emphasis discriminating natural anthropogenic ecosystems. An approach adjusting reduce was also proposed. study conducted in seven ecosystems: four were three anthropogenically transformed. Samples soil anim...

2006
Karline soetaert

Diversity indices, although designed for comparative purposes, often cannot be used as such, due to their sample-size dependence. I t is argued here that this dependence is more pronounced in h~gh divers~ty than in low diversity assemblages and that indices more sensitive to rarer species require larger sample sizes to estimate diversity with reasonable precision than indices which put more wei...

 Communities or ecosystems with higher biodiversity also have higher levels of ecosystem function and services, so the relationship between functional diversity and sustainability of plant communities is essential to predict ecosystem functioning. The aim of the present study was to investigate the relationship between carbon stocks and different species diversity and functional indices as well...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه اصفهان - دانشکده زبانهای خارجی 1389

abstract the current study sets out 1) to investigate the strategic needs of iranian efl learners in reading literary and non-literary texts; 2) to shed some light on the differences between reading literary and non-literary texts; and 3) to specify the differences in the interaction of participants with texts while reading two literary subgenres ( i.e., short story and literary essays). to ...

Journal: :journal of rangeland science 2015
tina salarian mohammad hassan jouri diana askarizadeh mahdieh mahmoudi

recent attitude of vegetation assessors is using of new ecologic approaches to evaluate and analyse the complex rangeland ecosystems. plant diversity is the most important indices to assess the ecological changes of rangelands. in order to survey of plant indices of rangelands, two exclosure areas (long-term and mid-term) and a grazing area in rangelands of javaherdeh (ramsar, iran) were select...

پایان نامه :دانشگاه آزاد اسلامی - دانشگاه آزاد اسلامی واحد مرودشت - دانشکده علوم تربیتی و روانشناسی 1392

the purpose of this study was to investigate the relationship between family functioning and marital adjustment humor couples are due to the nature and objectives of the research and application of methods for its implementation correlation was used. the study population consisted of all the couples in the city who uses random cluster sampling of 200 students were selected as sample. data from ...

2014
E Kathryn Morris Tancredi Caruso François Buscot Markus Fischer Christine Hancock Tanja S Maier Torsten Meiners Caroline Müller Elisabeth Obermaier Daniel Prati Stephanie A Socher Ilja Sonnemann Nicole Wäschke Tesfaye Wubet Susanne Wurst Matthias C Rillig

Biodiversity, a multidimensional property of natural systems, is difficult to quantify partly because of the multitude of indices proposed for this purpose. Indices aim to describe general properties of communities that allow us to compare different regions, taxa, and trophic levels. Therefore, they are of fundamental importance for environmental monitoring and conservation, although there is n...

Journal: :Ecology 2008
Sébastien Villéger Norman W H Mason David Mouillot

Functional diversity is increasingly identified as an important driver of ecosystem functioning. Various indices have been proposed to measure the functional diversity of a community, but there is still no consensus on which are most suitable. Indeed, none of the existing indices meets all the criteria required for general use. The main criteria are that they must be designed to deal with sever...

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...

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