The role of slope as an environmental variable in plant biodiversity change in Aegean rangelands by SHE analysis: The case of Çakmar rangeland

Abstract

Rangelands, which have rich plant and animal biodiversity, are also very important as a source of roughage for livestock. Rangeland vegetation patterns vary considerably under the influence of environmental factors. Indicator factors need to be identified and analyzed in order to manage conservation and utilization objectives. In rangelands of the Aegean region, the slope factor can greatly affect the rangeland plant biodiversity in areas close to the base rangeland. In order to investigate the spatial distribution and species variation in plant biodiversity caused by slope, 6 rangeland sections with different slopes were sampled in Koçarlı region (Aydın / Türkiye). Sampling was carried out using the transect method in the spring 2017 based on field observations. Following sampling, indicator species and species distribution and abundance were determined. Alpha biodiversity indices were used to determine the change in species biodiversity by SHE analysis. SHE analysis tests the relationship between S (species richness), H (Shannon-Wiener diversity index) and E (equality). This method aims to examine the contribution of the number of species and the concept of equity in the context of diversity. According to the information obtained as a result of the analysis, it was seen that the increase in slope may cause a decrease in species biodiversity. More species diversity was found in rangelands with low base and slope. Factors such as erosion and water transport affect the canopy and species abundance in high slope rangelands. However, other factors such as grazing intensity can reverse this situation. For this purpose, it has been determined that slope is an important environmental variable when preparing management plans based on grazing capacity and grazing animal species in vegetation studies.