Plant Species Diversity in Jokhaneh Plain and Southern Slope of the Nil Mt. in Kohgilouyeh va Boyerahmad Province (Central Zagros Region of Iran)

Plant species diversity in Jokhaneh plain and the southern slope of Nil Mt. is investigated in order to determine the flora and life forms and chorotypes of plants in this area. The studied area is located in Kohgilouyeh va Boyerahmad province, covers 22’475 hectares and its average elevation is 2’315 m above sea level. In spite of a few studies in this region, broad knowledge of the flora of this area does not exist. In this study, plants were collected randomly along the growing seasons during 2015-2016. Vegetation of the studied area comprised of 157 species and 124 genera belonging to 42 families. Asteraceae, Lamiaceae and Poaceae were the most species-rich families. The most species-rich genera were Astragalus, Salvia, Scorzonera, Ranunculus, Galium and Bromus. Hemicryptophytes and therophytes were dominant life forms in this area. Endemic elements constitute 61% (92 species) of this flora, of which, 23 species were endemic to Irano-Turanian region. Species list of this area was both compared and combined with those of 27 more local floras in order to perform multivariate floristic analysis based on presence/absence data of 2039 plant species × 28 floras. Results showed that the set of local floras could be divided into four distinct clusters, showing geographical distribution of floristic diversity along NS, WE and center of the Zagros run. This study highlights the importance of the study area by introducing eleven species not previously collected from the region consisting 27 local floras, and also the importance of multivariate analyses in comparative floristic studies.