Edge Effects in Two Secondary Tropical Montane Rainforests at Jianfengling, Hainan Island of China

The strength and distance of edge effects in two secondary tropical montane rainforests at Jianfengling, Hainan Island of China were predicted with a newly proposed model:Y=a+e01-(D/Dmax),where Y was the value of a variable measured;e0 was the maximum value of edge effects;D was the distance from the edge to a point at which Y was recorded; Dmax was the distance from the edge to the point at which edge effects reached zero;and α was a constant. The species richness of plants with diameter at breast height less than 5 cm obtained from 44 plots of 4 m2 in two forests each containing a secondary forest after clear-cut and a remined forest was used to fit the model and the following results were obtained.The edge effects in the tropical montane rainforests were well described by the proposed model;The maximum distance (Dmax) at which edge effects reached zero was,in general,less than 15 m;and at the same plot,the edge effects on species richness of the remaining forests and on that of the secondary-forests after clear cut were not significantly different.