Effects of topographical factors on distribution of Phyllostachys pubescens in Wuyishan Nature Reserve, Fujian Province, China

Based on 31 sample plots, 9 community types of bamboo (Phyllostachys pubescens) forest from Wuyishan Nature Reserve, Fujian Province, were identified by cluster analysis in PC-ORD 4.0. The distribution of these 9 types was mapped based on the distribution map derived from aerial photos (1980) and two sets of Landsat TM (Thematic Map) images (1998, 2000) integrated with the data of the forest inventory in the whole reserve. Topographic features such as altitude, slope and aspect were derived from a Digital Elevation Model (DEM) created by digitizing the contour map in 100 m intervals (1 50 000 ). These features were then applied to spatial overlay analysis of bamboo distribution. The pure bamboo forest (40.6%) and Phyllostachys pubescens - Castanopsis eyrei bamboo forest (20.3%) were the two major types of bamboo forest in Wuyishan Nature Reserve. Maximum area of bamboo forest was recorded at the altitude of 500-700 m a.s.l. The proportion of bamboo forest within each altitudinal band declined with increasing altitude. Shannon-Wiener index (H′) of tree layer increased and diameter of breast height (DBH) decreased along the altitudinal gradient. The area of bamboo forests on the southeast and northwest slopes were larger than on other exposures. The area of bamboo forest decreased with the increasing slope.