Investigation of exclusor, conventional and excessive utilization effects on plant diversity in Semi-arid Rangelands

For a correct and useful management of Range Ecosystems, requires to sufficientinformation about the extremity amount of grazing and it’s impact on the speciesDiversity and Richness of rangelands. This investigation done in three Refrence(Excluser), Key (Indeginous utilization) and Critical (Excessive grazing) regionsplace in Khabr National Park and vicinity areas which is 6000 hectars, inorder to compare plant and Richress species. In this inquiry, plant species wasdetermind via shanon index in Statistical methodology software and richnessspecies was determined by the means of RAREFRAC.BAS Software, throughputting 1×0.5( 120 meter) plots, To count the species numbres, in oder tonomination species diversity and richness, and in addition 120 other plots with2×1.5 dimensions was put to determine the percentage of canopy coverageby the method of Systematic-Random, was determined in three selected areaof Refrence, Key and Critical. Mathematics Expectation of species richness inRefrence, key and critical areas, was sequence 24 ,32 and 14, wich affects ofspecies richnes Followed: Refrence > key > critical. The average of coeficients, wich obtained of shannon Index was 1.9662 in Refrence area and 1.826 in keyand 1.052 in critical area. Plant diversity in refrence area and key area don’thave important differences, but there are important differences between criticalarea with refrence and key areas. In critical area richnes and species diversityare strongly reduced because it is excessive and out of season grazing, soplatability are reduced.

کلیدواژه ها:

Species diversity ، species richness ، shannon index ، Mathematics Expectation ، Plant form