Plant species diversity always implies ecosystem stability against environmental and biological disturbance. In order to investigate the effects of grazing management on species diversity indices, 15 rangelands under livestock grazing and one rangeland under wildlife grazing (especially deer) were selected in the Mouteh Wildlife Sanctuary. On the basis of distance to villages and watering points, fifty-six sites in the rangelands were selected. Sampling method had a randomized-systematic design, and two 100-meter long transects were established perpendicular to each other with three replications in each site. Vegetation percentage was recorded separately for each species type and life form along the transects. Species richness, heterogeneity and evenness indices were calculated from cover data using PAST and Excel software. Parametric diversity indices including log series, log normal, geometric and broken stick were fitted in both livestock and wildlife grazing areas. The results showed that, although the species diversity and evenness in the wildlife area were higher than that of the livestock grazing area, these indices were not significantly different (α = 5%). According to the results, higher species richness was recorded in the area under livestock grazing. The Menhinick (2.41) and Margalef (3.03) richness indices in livestock grazing areas had significantly higher values compared to Mouteh Wildlife Sanctuary with the Menhinick (1.52) and Margalef (2.12) richness indices (α = 5%). The logarithmic diagram in the livestock grazing and wildlife grazing areas followed the brocken stick model, indicating the presence of dominant species and limited species with moderate frequency. The result of CCA analysis showed that the two study areas were properly separated from each other in the ordination space in terms of management, vegetation and species richness index.

Keywords: Species diversity, Grazing livestock, Mouteh Wildlife Sanctuary, Canonical Correspondence Analysis

Full-Text [PDF 694 kb]   (1312 Downloads)