Plants Species Diversity in Hyrcanian Hardwood Forests, Northern Iran (Case Study: Mazandaran Province)

In order to better understand and manage forest ecosystems, it is important to study the relationship between environmental factors and plants in these ecosystems. We investigated plant species diversity of three hardwood forest stands in the Hyrcanian forests, Sari, northern Iran. Our aim was to determine the effect of forest stand type on the diversity of plant species. One plot 150 × 150 m established at the center of each forest stand and in each plot, nine subplots 50 × 50 m were selected. Diversity values (Richness, diversity and evenness indices) were measured in five sample areas 0.01 ha per 50 × 50 m quadrates by estimating cover percentage of each species. The results showed that Geophytes (43.33%) had the highest life form spectrum among species. JACCARD'S similarity index revealed that the highest values exist between Parrotia-Carpinus and Carpinus stands. All herb layer species diversity indices varied significantly among different forest stands. Cover percentage significantly positively correlated with diversity indices in Parrotia-Carpinus stand. Diversity and richness indices of herb-layers plants were significantly negatively correlated with cover percentage in Fagus stand. Correlation analysis between all diversity measures and cover percentage in Carpinus stand wasn't significant. The result of the present study revealed that species diversity in temperate broad-leaved deciduous forest was significantly influenced by forest stand type.