Species Diversity of Forest Plants in Eastern Mountain Area of Heilongjiang Province

The species diversity of virgin forests and secondary forests in eastern mountain area of Heilongjiang Province were studied composing with quantitative community dynamics.And we researched the relationship between community dynamics,environmental gradient,growth rate,disturbance of forest and species diversity.The results showed that species diversity of secondary forests is higher than that of virgin forest,but the evenness is lower.The forest productivity is middle in the community that the species diversity is higher,however,not only the productivity is the highest but also the species diversity is the lowest.The species diversity is the highest in the community of middle intensive disturbance.The species diversity indices are increasing from the initial stage to the middle stage of succession then decreasing in the climax stage.