Evaluation of plant communities using new indices of taxonomic diversity (Case study: rangelands around Tehran province

Many studies in recent years have investigated biodiversity at the level of individuals or species and less attention has been paid to the relationships of species to higher taxonomic levels. New indicators of taxonomic diversity by considering the relationships between species distribution at different levels of relatedness relative to other more conventional indicators of biodiversity provide more information for ecologist on the higher level of taxa. In this study using new indices of taxonomic diversity, was conducted on the taxonomic diversity and distinctness of plant species in six rangeland sites around Tehran province in the six taxonomic levels. The results showed that Saveh and Salafchegan allocated the most (∆=67.8, *∆=71.3) and the least (∆=61.4, *∆=64.4) taxonomic diversity and taxonomic distinctness indices, respectively. This means that there are a lot of high path along the phylogenetic tree species in Saveh site. The average index of taxonomic distinctness shows there are fewer orders for entire families and species in Salafchegan (Δ=65.2). Results indicated that Salafchegan, Alborz and Damavand sites compared with Saveh, Firouzkouh and Semnan sites had more relative speciation and heterogeneous evolutionary structures. In other words, large part of these sites often has gathered asymmetrical in small number of families. In general taxonomic diversity indices along with other species diversity indices can be used to assess more complete and more comprehensive view of biodiversity and ecosystem process particularly in rangelands community analyses.