Document Type : Research Paper
Authors
Abstract
To identify destroyed area and to introduce a piospher, pattern of vegetation composition was considered at different distances from a water point.Therefore in 113 plots, species density and vegetation cover were evaluated.To identify the patterns of vegetation composition, Clustering analysis was applied on species density and vegetation cover and three distinct groups of vegetation composition were obtained. ANOVA analysis showed that three groups were different (p<0/01). By using DCA, relations between groups and species were evaluated. Result showed that there was a piospher on 300 m from water point. In this zone, vegetation composition extremely changed due to heavy grazing and palatable species were replaced by annual or perennial unpalatable species but with distance from water point, perennial and palatable species increased. Study of relations between vegetation compositions (was obtained by plant functional types) and grazing intensity showed that in addition of quantitative methods, qualitative methods such as vegetation composition and plant functional types could be an appropriate method to determine ecosystem condition in shrublands.
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