茂兰喀斯特森林林隙边缘木特征的研究

STUDIES ON THE CHARACTERISTICS OF GAP BORDER TREES IN THE KARST FOREST IN MAOLAN NATURE RESERVE OF GUIZHOU PROVINCE

为探讨茂兰喀斯特森林林隙边缘木对林隙干扰的响应．通过对60个林隙485株边缘木的调查，研究其数量、种类、大小结构、偏冠率的分布及其与林隙面积大小的关系。结果表明：边缘木的径级结构呈偏左的正态分布，而高度结构呈正态分布。约17．32％的边缘木未出现偏冠现象，绝大多数边缘木的偏冠率在0．5～0．7之间（占63．30％），不同树种间的偏冠有显著差异。单个林隙边缘木的平均偏冠率与冠林隙和扩展林隙面积大小均无显著的线性关系．单个林隙的边缘木最少为4株，最多为16株，平均每个林隙拥有8．08株边缘木。

Four hundred anti eighty tlve trees at gap border in 60 gaps in the Karst forest at Maolan Nature Reserve in Guizhou Province were investigated to study the responses of gap border trees （GBT） to gap disturbance. The structure of DBH （diameter at breast height） classes of the GBTs showed a left - skew distribution, but tree height elaases showed a normal distribution. The structure of DBH classes and tree height classes din not show a distinctive change pattern with the change of gap size. The ratios of crown inclination （RC1） of most GBTs were in the range of 0.5 to 0.7 while about 17.32% of GBTs had regular crowns. The difference in RCIs of species was significant. The relationship of average RCI in each gap with canopy gap size and with expanded gap size did not fit tbe linear function. The maximum number of GBTs was 16 and the minimum number was 4, averaging 8.08 GBTs per gap.