Comparison of vegetation and soil diversity inside and outside the enclosure (Case study: Artemisia habitats of Dehno, Bardsir, Kerman)

The loss of vegetation and the prevalence of decay in Artemisia habitats due to climate change and management factors necessitate the need to focus on a conservation approach in the management of these ecosystems. In this regard, the effect of the conservation approach (exclosure with a history of 30 years) on the structural components of vegetation, soil characteristics, and values of numerical indicators of species diversity in the Artemisia habitats of the Dehno-Bardsir region was investigated. For this purpose, vegetation sampling was performed during the growing season of 2013 inside 45 two-square-meter plots located along three transects of 150 meters, inside and outside the enclosed area. Within each plot, the percentage of canopy cover of species was estimated and the number of their bases was counted based on the percentage of canopy cover of species, indices of species diversity were calculated. Along each of the transects, a composite soil sample was taken from a depth of 0-30, and their physical and chemical properties were measured. Based on the results, in terms of canopy cover percentage, only in the case of Stipa arabica, there was a significant difference between enclosed and non-enclosed areas. In terms of the number of bases per hectare, there was only a significant difference between Zygophyllum atriplicoides and Stipa arabica, and in terms of presence only between Artemisia sieberi, Stipa arabica, and Zygophyllum atriplicoides, there was a significant difference inside and outside the enclosure. In sum, the exclosure will cause Stipa arabica to dominate the area. There was no significant difference between soil properties (percentage of clay, silt, and sand, electrical conductivity, acidity of saturated mud, amount of lime, calcium, magnesium, and sodium) in the two places. The amount of species richness in the enclosure area (with 21 species) was higher than in the grazing area (with 16 species). The values of Simpson and Shannon-Weiner indices also indicate no difference between the two places for evenness and heterogeneity of vegetation. What is certain is that the results of three decades of exclosure showed that the process of vegetation change in the valleys of arid regions is slow. Applying a conservation approach in such ecosystems will be effective in the long run.