Plant Diversity in Ecosystem Units of Caspian Lowland Forests (Case study: Khanikan forest, Chalous)

Due to investigation of plant diversity in ecosystem units، 268. 7 ha-1 of lowland forest in Khanikan were studied. In order to investigate of plant covers sixty plots (20m × 20m for each) were taken by a systematic random sampled method. Five ecosystem units were classified using of TWINSPAN program. For analysis of plant diversity، Simpson، Shannon Wiener، McIntosh، Margalef، Menhenic، Peet and Hill indices had been used. Analysis of variance showed that ecosystem units had significant difference viewpoint Simpson، Margalef and Menhenic indices value. The other diversity indices hadn’t significant differences in ecosystem units. The maximum and minimum of Simpson index value were showed in 5th and 3rd ecosystem units، respectively. The highest value of Margalef and Menhenic indices devoted to 3rd ecosystem unit and the least value was showed in 1st ecosystem unit. Plant diversity in ecosystem units are influenced of soil characteristics by reason homogeneity of slope، aspect and altitude in study area.