impacts of effluent from fish farming activities on fluvial ecosystems lead to deterioration of water quality and changes in the macroinvertebrates assemblage. in this study, the influence of fish farm effluents on water quality and macroinvertebrates communities of tajan river was investigated to evaluate the suitability of macroinvertebrates based on biological metrics and indices. benthic ma...

Indices summarizing community structure are used to evaluate fundamental community ecology, species interaction, biogeographical factors, and environmental stress. Some of these indices are insensitive to gross community changes induced by contaminants of pollution. Diversity indices and similarity indices are reviewed considering their ecological application, both theoretical and practical. Fo...

Diversity indices are frequently applied in the form of ratios of absolute diversity to the maximum diversity possible. Regardless of whether the maximum diversity is defined to be limited by the number of species or by the number of individuals present, the resultant indices can be shown to possess mathematically undesirable qualities. All such indices, including equitability as measured by Pi...

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...

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...

the diversity and richness of species are of important components to evaluate the health of ecologic system of rangelands. this research was conducted to investigate the biodiversity in riparian and neighboring areas via comparison of indices in javaherdeh rangeland of ramsar. plot-transects was randomly used to estimate diversity, richness, dominance, and evenness indices in two regions. multi...

one of the main objectives of ecosystem management is to preserve the speciesdiversity. many researchers regard higher species diversity as the stability of ecologicalsystems. the aim of this study is to investigate the stability and relationships betweentopographical factors with diversity indices in ghorkhud mountainous rangeland innorthern khorasan province, iran. for data sampling (2012), l...