shannon-wiener index

The aim of this study was to identify environmental factors affecting the abundance and biodiversity of fish communities in the Dinor River in Kermanshah province. For this purpose, six stations were selected for sampling fish along the Dinor River in June 2018. In addition, physicochemical parameters and biodiversity indices of fish were determined. Canonical Correspondence Analysis (CCA) was used to determine the environmental factors affecting biodiversity indices and fish species. Based on the results, a total of 2543 fish samples were caught from in Dinor River, which belonged to 20 species. Most fish species belonged to the Cyprinidae family. Alburnus sellal (with 1358 samples) and Capoeta trutta (with 1 sample) showed the highest and lowest abundance in Dinor River, respectively. Medium bedrock diameter with a coefficient of 0.65, water flow velocity with a coefficient of 0.60 and TDS with a coefficient of 0.52 were identified as the most effective environmental variables on fish abundance in the Dinor River. In addition, among the studied environmental variables, river width with a coefficient of 0.64, depth with a coefficient of 0.58, EC with a coefficient of 0.44 and TDS with a coefficient of 0.42 showed the most significant contribution to fish species diversity in the Dinor River.

The present study was conducted to investigate the effects of physical factors on the diversity of species of Carabidae (Coleoptera: Carabidae) in three regions of Karaj, Eshtehard, and Taleghan, Alborz province. To this end, during 2015-2016, sampling was carried out using pitfall traps and physical factors. In this regard, the elevation, slope, direction, precipitation, temperature, soil texture, grain size of soil, and percentage of vegetation were recorded in each studied station. Based on the results, in total, 329 specimens including 38 species were identified in the three studied areas. Pearson and Spearman tests were used to investigate the relationships between the species diversity index (Shannon's Diversity Index) and the studied factors. Also, the effect of habitat physical parameters on the diversity of the species of Carabidae in the studied areas was analyzed using Canonical Correspondence Analysis (CCA). The results of the study showed that no significant relationship between the Shannon-Wiener Index and studied parameters (P<0.05). Species diversity was affected by temperature, the three parameters of altitude, soil texture, and grain size of soil, and the four parameters of direction, slope, precipitation, and vegetation percentage in Karaj, Eshtehard, and Taleghan, respectively.