摘要：The depletion of forest in developing countries due to extended pastures,agricultural land,fuel wood and etc.is a serious concern.Therefore planting trees for reforestation and expanding forest area is an essential assignment.Forest plantation with a basic criterion affects to understory plant diversity.These effects may make some species absent or appear.The aim of this study was to assess the plant diversity of two different plantations which established by Pin us teada and Acer insign and compare them with a natural forest stand which were similar in geographical and climatic conditions.Twenty sample plots with 32 square meters were randomly selected.In each plot all herbaceous species were recorded.Richness and Evenness of plant species werecalculated using the biodiversity indices (Simpson index and Margalov index).The obtained results showed that the value of plant diversity was higher in natural forest,while Acer plantation had the lowest value.The Richness and Evenness value were higher in natural forest stand,while Richness and Evenness value were lower for Pin us teada and Acer insign plantation respectively.
