Study on the Ecotypes of Allium wallichii in Jizu Mountain,Binchuan County, Yunnan Province Study on the Population and Differentiation of Allium wallichii in Jizu Mountain, Binchuan County, Yunnan Province STUDIES ON INTERSPECIFIC ASSOCIATION OF BOTH Castanopsis orthacantha AND Castanopsis delavayi COMMUNITIES AT JIZU MOUNTAIN,YUNNAN PROVINCE