Classification of plant species according to the Grime’s CSR theory (Case study: Haftadgholeh and Meyghan playa of Aak)

Understanding the role of plant species in plant composition is very important in the study of climate change processes, understanding the properties of ecosystems such as sustainability, flexibility and ecosystem assessment.The classification of plant species according to the Grime’s CSR strategies was studied in Haftadgholeh and Meyghan playa of Arak. Random- Systematic design was applied to sampling, and the characteristics of plant species were recorded according to Hodgson et al., 1999 method. A total number of 172 vascular plant taxa belonging to 46 families and 136 genera were studied. The life form spectrum, based on Raunkiaer system, revealed that Hemicryptophytes and Therophytes have been the most dominant life forms. The floristic composition of the area is strongly influenced by large number of Irano-Turanian elements.The most important strategies were competitive-ruderal (CR) (36.5%), competitive-stress tolerant (CS) (18.8%) and competitive/competitive-ruderal (C/CR) (12.9%). Few species (4 species, especially tree and shrub species present in less intact areas of Haftadgholeh), exhibited a purely competitive (C) strategy. It seems that livestock grazing and stress caused by soil salinity, altitude and drought, increase the frequency of competitive- ruderal group strategies such as CR, C / CR, R / CR and CR / CSR and SC, C/SC, S/SC, SC/CSR, SR and SR/CSR, respectively. The data generated in this research can be the basis for using the CSR classification model to determine the response of plant species to the pattern of environmental factors change, disturbance as well as the evaluation of managed ecosystems.