Tree ring-climate response and endangered mechanism deliberation of Japanese yew (Taxus cuspidata) in Muling Nature Reserve Diurnal Changes of Chlorophyll Fluorescence Characteristics of Japanese Yew Seedlings under Different Light Conditions Distribution and variation of paclitaxel and cephalomannine contents in wild Taxus cuspidata The influences of site factors on the interspecific competition between Japanese yew (Taxus cuspidata) and other tree species