نتایج جستجو برای: richness margalef index
تعداد نتایج: 415206 فیلتر نتایج به سال:
Including or excluding rare taxa in bioassessment is a controversial topic, which essentially affects the reliability and accuracy of the result. In the present paper, we hypothesize that biological indices such as Shannon-Wiener index, Simpson's index, Margalef index, evenness, BMWP (biological monitoring working party), and ASPT (Average Score Per Taxon) respond differently to rare taxa exclu...
The ecosystem health of rivers downstream of dams is among the issues that has become focus of attention of many researchers particularly in the recent years. This paper aims to deal with the question, how the environmental health of a river ecosystem can be addressed in water resources planning and management studies. In this study, different parameters affecting the ecosystem of river-reservo...
Bale Mountains National Park is one of the protected areas in Ethiopia that holds largest area Afroalpine habitat Africa and second stand moist tropical forest. Nevertheless, human settlements, overgrazing, recurrent fire are main problems park. This study aimed to determine effects human-induced landscape change floristic composition structure The vegetation data were collected systematically ...
The understorey is one type of tropical forest vegetation that contributes to the complexity structure. habitat closely related condition vegetation. This study aims determine structure and composition support ecological function in Malagembol Block, Mount Tilu Nature Reserve. sample collection was carried out using plot method. A total three main plots measuring 10×100 m2 were divided into ten...
Abstract The use of agrochemicals in agriculture may impact aquatic ecosystems, particularly influencing the stream insect communities. Among insects, family Chironomidae is most abundant and species-diverse group found freshwater ecosystems. However, southern hemisphere, studies with are still sparse, compared to Europe North America. present study evaluates responses species (Insecta: Diptera...
This study aimed to compare plant species diversity indices (diversity and richness) and some physico-chemical properties of soil among forest, ecotone and rangeland habitats. Vegetation sampling was done randomly at each habitat. One dominant community was selected in each habitat and one key area was distinguished in each community and 8×1m2 plots were randomly established in each key area. I...
The feeding diversity of macroinvertebrates from the estuary of Mondego was estimated with Shannon–Wiener complementary evenness following the methodology presented in Gamito and Furtado (2009. Ecological Indicators, 9: 1009-1019). Results were compared with those from BAT (Benthic Assessment Tool; Teixeira et al., 2009. Marine Pollution Bulletin, 58: 1477-1786) applied to the same data set, ob...
Phytoplankton plays an important role in the material cycle and energy flow of the ecosystem, Therefore in this study, the distribution, frequency, and biodiversity of phytoplankton in Elimalat Lake were investigated. Sampling was performed in Elimalat Lake sessonally, located in Nur City, Mazandaran province, in 2019. In this study, 70 species of phytoplankton were classified into 5 phylum ...
Abandonment of arable lands is the starting point of vegetation succession. The trajectory and speed of succession can be different according to the time of abandonment. The aim of this study is to assess the effect of abandonment periods on species richness, diversity and functional groups in shrublands and grasslands of Shirmard rangelands in Chaharmahal va Bakhtiri, Iran. A total of 96 abond...
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