بررسي فلور آبخيز سد كبار قم

Survey to flora of Kohar watershed in Chum area , Iran.

The region under study with the area of 16873 hectars is located in the south of (Thum. The highest altitude of it is 3070 m. above the sea level and the lowest is 1050m. The average rainfall, according to the neighbourhood synoptic station is ca. 252.8mm. Researches and investigations on the plant vegetation of the mentioned area have revealed the presence of 484 species belonging to 62 families and 274 genera. The largest plant f tmiiy,in terms of number of species is asteraceae with 79 species and the largest genus, in terms of species is astragalus from papilionaceae family with l9 species. ʹfhc diagram of plantbiotic spectrum indicated that the life forms of the plant species of the mentioned area include: Hemicryptophytes 41.96%, therophytes 29.65%, Chamaephytes 12.94%, geophytes 10.23%, helophytes 0.62% and phanerophytes 4.60%, representing the environment with a cold and temperate climate. 410 species(84.71°/0) of the area are exclusively Irano-Turanian region. Furthermore, according to the IUCN or the World Conservation Union, three cataegories of plant species so called vulnerable. Lower risk and data deficient are determined. There are,in total, 69 threatened plant species in this area.