Ecology, Environment and Conservation Paper

THE EFFECT OF EXCLOSURE ON FLORISTIC COMPOSITION AND VEGETATION DIVERSITY IN DRY RANGELANDS (CASE STUDY: SOUTHERN RANGELANDS OF MARKAZI PROVINCE IN IRAN)

Jamal Bakhahi, Seyed Akbar Javadi, Ali Tavili and Hossein Arzani

Abstract

Exclosure is a vegetative regeneration strategy that has had different effects in different climate zones. The main objective of this study is to investigate the effects of exclosure on diversity and growth forms of plant species in dry rangelands. Floristic composition and life forms were studied in two levels (grazing areas and exclosed rangelands) using different indices. For this purpose, using field observations and existing records, two protected areas with ages of 8 and 11 years old and two regions with moderate and heavy grazing intensity were selected for sampling. Measures taken in each area included identification of species, counting plant species, counting number of individuals in each species and presence or absence of plant species. The variability, uniformity and similarity coefficients of species in each region were calculated and statistically compared. The results showed that as a result of heavy grazing of livestock, annual plants such as Poa bulbosa and Hordeum murinum and non-palatable plants such as Peganum harmala increased. Also, exclosure has a significant effect on the improvement of vegetation, diversity and palatability in the region.