Saeed Ghanbari - Department Rangeland and Watershed Management, Faculty of Natural resources and environment, University of Birjand
Masoumeh Zohrekermani, - Department Rangeland and Watershed Management, Faculty of Natural resources and environment, University of Birjand
Sholeh Ghollasi Mood - Department Rangeland and Watershed Management, Faculty of Natural resources and environment, University of Birjand

In order to manage rangeland, the relationship between their components must be known. One of the main components of these ecosystems is vegetation and its composition, which is controlled by environmental factors. In other words, the distribution pattern of plant communities is influenced by many environmental factors. Understanding how these changes occur is the most important tool for adopting management measures for the principle exploitation of pastures, which makes it possible to achieve optimal scientific and practical solutions for more correct management. This research was carried out in Bahlgerd in order to compare the diversity of elevation, slope and tilt direction. To achieve the research goal, 10 ×10m plots and systematic random sampling were performed. In the end, the data were analyzed using Excel, EstimateS and Arc GIS software. It should also be noted that three study areas were determined in the southeastern Khorasan province, including the northern, southern, and the whole region. Each of the results was separately expressed and analyzed in each region. Finally, the results indicate that the highest number of vegetation basins on the slope of 0 to 5 percent and the direction of the northwest slope, as well as the altitudes of 1840 to 1890,are also present. The majority of plants in the southern Khorasan region belong to therophyte

Bahlgerd, Ecological Index, Physiography, Species diversity