Application of Species and Functional Diversity Indices in Monitoring the Effects of Grazing Management (A Case Study of the Bozdaghi Area, North Khorasan)

Abstract :

A fundamental basis in applied studies across any region is the understanding and conservation of natural ecosystems. Ecological assessment of vegetation cover plays a pivotal role in natural resource management. Therefore, the objective of this study was to investigate the impact of livestock grazing management (exclosure and grazing) on vegetation characteristics, including species diversity, functional diversity, plant composition, and indicator species, in the Bozdaghi region, Bojnord County, North Khorasan Province. To measure biodiversity, species diversity indices (Hill's index, species richness, evenness, Shannon diversity, and Simpson diversity) and functional diversity indices (single-trait and multi-trait) were employed. Plant composition between the two management systems was compared using Detrended Correspondence Analysis (DCA), and indicator species were determined using Indicator Species Analysis and the Monte Carlo test. Based on the results in the Bozdaghi region, livestock grazing significantly reduced species richness (P-value < 0.05), but had no significant effect on other species diversity indices. Furthermore, livestock grazing significantly reduced plant functional diversity. According to the DCA results, grazing led to distinct vegetation compositions between the exclosure and grazed areas. Ultimately, grazing resulted in the presence of only one indicator species in the grazed area, whereas the exclosed area contained 16 indicator species. The results of this study indicated that the Bozdaghi region possesses high biodiversity, and the utilization of management tools such as grazing exclosure exerts a positive impact on increasing species and functional diversity, as well as enhancing the number of indicator species.

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