Abstract:

This paper focuses on the self-regulation of Lithocarpus xylocarpus population, which is one of main dominant species of the mountainous humid evergreen broad-leaf forest in Xujiaba region, Ailao Mountain stituated in the mid-south of Yunnan province (24˚31′–24˚35′N,101˚00′– 101˚03′E). It has been found that the relationship between the population density (D) and the mean plant biomass (B) during the self-thinning can be described as:

B= 1825267.081D-2.8208 (l10≤D≤1051)

where B is in t/stem, D is in stems/ha.

The percentages of importance value of Lithocarpus xylocarpus, Lithocarpus chintungensis and Castanopsis wattii have been regarded as the measure of the niche overlap, which results in a new method to calculate competition coefficient, the final result of competition has been discussed with the Lotka-Volterre equation of competition. The analysis showed that the relative dominance of L. xylocarpus, L. chintungensis and C. wattii are respectively 29.52%, 39.90% and 30.58%. Hence three species can jointly dominate a community.