古田山常绿阔叶林优势树种甜槠和木荷的空间格局分析

基于24hm2古田山中亚热带常绿阔叶林长期监测样地调查资料,采用Ripley的K函数点格局分析等方法,具体分析了古田山常绿阔叶林优势树种甜槠(Castanopsis eyrei)与木荷(Schima superba)不同年龄阶段的空间分布格局以及它们之间的空间关联性。结果表明:两种优势物种在总体上及不同年龄阶段主要呈聚集分布,且随年龄阶段的增加,聚集程度有降低的趋势。两物种在大尺度直观上有明显的生境偏好。两种优势物种的幼树、小树与大树和老树主要呈空间负相关或无空间关联性,与中树呈空间正相关。甜槠中树与大树、大树与老树主要呈空间正相关,而甜槠的中树与老树呈空间负相关。木荷中树与大树和老树、大树与老树均呈现空间负相关或无关联。我们发现古田山优势物种通过密度制约和Janzen-Connell效应释放空间,为其他物种共存提供了条件,密度制约和Janzen-Connell效应可能是古田山样地甜槠和木荷空间格局形成的重要原因。

Spatial patterns of Castanopsis eyrei and Schima superba in mid-subtropical broad-leaved evergreen forest in Gutianshan National Reserve,China

Aims Many mechanisms of forest patterns have been examined in tropical rain forest;however,there are only a handful of similar studies on subtropical broad-leaved evergreen forest.Our objective is to analyze the main mechanisms of distribution pattern of Castanopsis eyrei and Schima superba in GTS (Gutianshan) forest plot.Methods Based on a stem map of a 24 hm 2 permanent plot in the middle subtropical broad-leaved evergreen forest at Gutianshan National Reserve,we analyzed the distribution pattern of the d...