Plant Species Diversity in Relation to topography in the East of Dodangeh Forests, Mazandaran Province, Iran

Diversity of plant species in a community changes in response to topographic factors such as altitude، aspect and slope. This study examined diversity changes in relation to topography in Dodangeh Forests، South of Sari، Iran. Plant species were collected in sampling units and the cover percentage of each species was estimated based on 400 m2 quadrats. There were 237 plant species in the area. Quadrats divided into 7 altitudinal classes، 3 slope and 8 aspect ones. Discriminant function analysis showed that altitude is the most effective factor to discriminate plant communities. The data were also subjected to analysis by specific diversity packages to characterize and obtain species diversity and evenness indices as well as species abundance models. The highest species diversity (Shannon H'' =1. 5-1. 6) and evenness (Smith & Wilson’s E= 0. 38-0. 42) were observed in the moderate classes of altitude. South، southeast and southwest facing slopes were more diverse than northwest one because of more available radiation and temperature. Gleason’s continuum view of plant communities can be considered for vegetation of the area.