Comparison of Plant Species Diversity and Evenness in Different Grazing Levels Southeastern Slopes of Sabalan

Assess the diversity of the understanding of ecosystem function; maintain genetic resources, checking environmental changes, and success or failure will help natural resource management programs. Over-grazing and uncontrolled usage of rangelands are the most common and the most important factor of rangeland degradation which causes a reduction in species diversity.

In order to investigate the effect of different grazing intensities on species diversity and uniformity in the rangelands of the southeastern slopes of Sabalan, three habitats with different grazing managements including light, medium and severe grazing were selected and one square meter plots along three 200-meter transects were sampled. In each plot, the list of available species, canopy percentage and number of individuals of each plot were recorded. Simpson, Shannon and Brillon diversity indices and Camargo, Simpson and Smith-Wilson uniformity indices were calculated.

The results showed that the area with medium to light grazing intensity has the highest diversity and uniformity compared to the area with heavy grazing intensity which indicates favorable conditions for the establishment of several species. 

Discussion and Conclusions

Due to the significant effect of grazing intensity on diversity and richness indices, it is necessary for rangeland managers to control grazing intensity through management methods to maintain the diversity of rangeland ecosystems. Therefore, it is enough to target the management based on moderate grazing and bring the areas with intense grazing to the conditions of moderate grazing so that the good and tasty species gradually replace the woody and poor species. Desirable species and plant species and woody species are poor.