OICC Press Journal of Rangeland Science 2423-642X 1 1 2024 01 30 Investigation of Plant Diversity in Middle Rangelands of Taleghan by Using BIO-DAP EN F. Fahimipoor MSc, Graduated from Natural Resource Faculty, University of Tehran. M. A. Zare Chahouki Asistant Professor, Natural Recourse Faculty, University of Tehran M. Jafari Professor, Natural Resource Faculty, University of Tehran M. Goldansaz MSc, Graduated from Natural Resource Faculty, Islamic Azad University, Tehran Branch MSc, Graduated from Natural Resource Faculty, University of Tehran Z. Mohhebi MSc, Graduated from Natural Resource Faculty, University of Tehran Journal Article 2024 01 30 Plant Diversity conservation is a main objective in rangeland management. Plant diversity is a suitable index for showing the changes of vegetation in rangelands and has a high correlation with ecosystem parameters. Therefore, using this index it is possible to find the changes and manage the ecosystem correctly. The current research was performed to determine the species diversity in Fashandak rangelands of Taleghan. To do this, 110 plots each one with an area of 1 m2 were established based on randomized-systematic method and density of the species within each plot was recorded. Species properties including the related genus and family in addition to life form, growth form and biological type were determined. Shannon, Simpson and McIntosh diversity indexes were used. Results showed that diversity of Fashandak rangelands could be considered as moderate. The highest distribution frequency was related to the species of Bromus tomentellus, Hypericum perforatum and Thymus kotschyanus.