Department of Plant Sciences and Medicinal Plants, Faculty of Agricultre and Water Management Research, University of Mohaghegh Ardabibli, Ardabil
Abstract: (4824 Views)
Study of vegetation changes under open grazing system against non-grazing areas provides important information useful for future management of rangelands. In this study, the effect of exclosure on vegetation factors, species diversity and evenness were evaluated in the Urmia Lake surrounding rangelands. Chopanloo is a non-grazing site which was selected as exclosure areas and its vegetation status was compared with Khandam site as an open grazing site. Vegetation information were collected in thirty plots of 2 m2 set for each site within a systematic random design. Vegetation factors measured for the comparison were diversity and evenness. Samples were taken inside and outside of enclosure areas. Independent t tests used as the comparison method. Results showed that 21 species belonged to 20 genera and 10 families were available in the sampling areas. Vegetation factors (density of forbs, grasses, shrubs and total density; canopy cover of forbs, grasses, shrubs and total canopy cover) were significantly different in and out of the exclosure. This shows that aplication of exclosure increases the density and canopy cover of existing vegetative forms. The value of Margalef and Menhinick richness index were 4.36 and 3.29 inside the exclosure and 2.83 and 2.51 outside the exclosure, respectively. Which mean the differences between inside and outside of exclosure were significant. The values of diversity indicators also were significantly different for the two treatments. The Simpson index inside the exclosure was 0.86 and outside the exclosure was 0.66, and the value of the Shannon-Wiener index inside the exclosure was 2.31 and outside the exclosure was 1.67. But evenness indicator in the two areas was almost the same. In general, the exclosure region had more richness, diversity and evenness than the under grazing region. Results of this study suggests that application of grazing ban policy is effective for the study area. It has positive effect on stabilizing sand calmness of dust.
Type of Study:
Research |
Subject:
Special Received: 2020/07/29 | Accepted: 2020/07/31 | Published: 2020/07/31