Study of life form of plants in the forests of Guilan, Iran

Iran is one of the most important centers of biodiversity in the old world. About 22% of the total 8000 plant species are endemic to Iran. Therefore, study of the flora and vegetation is important. The northern forests of Iran are diverse ecosystems of Euxine-Hyrcanian province in Euro-Siberian region and Holarctic kingdom. Floristic Study of a habitat is valuable for continuing ecological research, management and conservation of plants. Richness and diversity of plants and various forest types in Guilan, 80 km to south of Sari, make it a unique habitat to study floristically. The eastern forests of Guilan, with the area of about 8000 ha., is located in the at 37°, 05' to 37°, 11'north latitude and 50°,00' to 50°, 14'east longitude. The altitude is varied from 500 to 1000 m. The mean annual precipitation is 406 mm. Plant species collections were performed in May, June and November of 2007. The species were identified and their chorology and life form were determined. The results revealed the existence of 158 plant species,belonging to 5 families of Pteridophytes and 52 families of Angiosperms. Most of species belong to Asteraceae, Poacaeae and Fabaceae,Lamiaceae, Rosaceae, respectively. According to Raunkiaer's classification of life forms, Hemicryptophytes, Therophytes and Phanerophytes, include 46%, 19%, 17%, and 4% of the total species, respectively. Chorotypes, based on Zohary, showed that most of the species belong to province Hyrcanian and Euro-Siberian-Mediterranean-IranoTuranean regions.