Floristic, life form and chorological studies of the Abshar protected area, Shirgah, Mazandaran Province, north of Iran

The Abshar protected area with 3639 ha and an altitude ranging from 400-855 m a.s.l. is one of the forest areas that due to its topography is covered by Carpinus betulus, Parrotia persica and Diospyros lotus speices. The floristic study of this area is long with sampling plots. The floristic-physiognomic investigation showed that flora of this region included 99 plant species which belonged to 81 genera and 49 families. The largest family was Rosaceae with 10 species. Classification based on life form spectrum indicated that geophytes (31.31%), phanerophytes (29.29%), hemicryptophytes (25.25%) and therophytes (14.14%) comprise the plants in the studied area. The results of chorological studies showed that the chorotype form Euro-Siberian elements (32 taxa, 32.32%) were the most important phytochorion in this area. Long period of wetness during the growing season and relatively high annual precipitation are the reasons of the high proportion of geophytes existence in the studied area. Phytogeographical comparison of the Abshar protected forest and the other forests in north of Iran identified two peaks in phytochoria curves, one in Euro-Siberian and the other one is in the Pluriregional elements.