Assessment of slope aspect and grazing intensity effects on species diversity indices using multi-scale C-plot rangeland ecosystems of Karsanak in Shahrekord

Considering the need for the rapid assessment of species diversity, it is essential to understand the easy application of the appropriate methods for measuring diversity. In order to measure diversity, the multi-scale C–plot was used. This plot was selected in Karsanak rangeland with two eastern and western slope aspects, and two grazing intensities: light and moderate. Four treatments were detected including light–eastern, light-western, moderate-eastern and moderate-western. At each sampling location, three C-plots to the dimensions of 10*10 m and at the distance of 200 meters were set up as a random-system for assessing species diversity. After collecting cover data in each site, diversity, richness and evenness indices were obtained via PAST software. Comparison of species diversity was performed in different treatments by analyzing variance (ANOVA) on SPSS. Plotted graphs were drawn within Excel. The results demonestrated that in all four locations there were significant differences in 5% level among species richness indices. It was also found that there was not only significant difference between diversity and evenness indices in different locations however, the indices values were higher in the eastern and western slope aspects with moderate grazing intensity. Increased indices values in the eastern and western slope aspects with moderate grazing intensity were attributed to the presence of invasive non-palatable and annual species. The eastern slope aspect with moderate grazing intensity due to suitable moisture conditions and the possibility of new specie presence was effective in increasing indices value. Moreover, species diversity was well illustrated by species-area curves. As a result, species diversity will be evaluated well with multi-scale plots such as C-plot.