Studies on the Characteristics of Gap Border Trees in the Subalpine Coniferous Forest in Western Sichuan

In order to explore the responses of gap border trees(GBT)to gap disturbance in subalpine primary conifer forests in the western Sichuan Province,the GBTs in the typical primary conifer forest at Dawodang within Wanglang Nature Reserve were surveyed and analyzed according to species, height, diameter at breast height (DBH), crow inclination and so on. The results showed that the size of GBTs accorded well with the one of the canopy trees in general stand while a few were smaller;it's feasible to regard the averaging heights of GBTs as the heights of their gaps;the ratio of crow inclination (RCI) of most GBTs were in the range of 0.5 and 0.7 while about 1/5 GBTs' crows were regular, and the RCIs difference of species were significant; the maximum number of GBTs in one gap was 17 while the minimum was 5, and averaging 9.51 GBTs per gap.