Study on the inter-species competition of Sassafras tsumu community in the mid-subtropics and the population density adjustment

The inter-species competition of Sassafras tsurnu community in the mid-subtropics is studied．The results show that in a steady state，the important percentages of ,Sassafras tsurnu and its main associated species-Betula luminifera and Castanopsis如rgesii are 80．64％，12．47％，and 6．89％，respectively．They share the environment resources in a good state，but the distribution is uneven．The density effective model is given by using the self-thinning model and adjusting the optimum adaption，the simulate result is good，reflecting the natural thinning of Sassafras tsurnu Hemsl population more accurately．