南岭东西段植物群落物种组成及其树种多样性垂直格局的比较  

Plant community composition and tree species diversity on eastern and western Nanling Mountains, China

作　　者：朱彪[1] 陈安平[1] 刘增力[1] 方精云[1] 

机构地区：[1]北京大学环境学院生态学系

出　　处：《生物多样性》2004年第1期53-62,共10页Biodiversity Science

基　　金：国家重点基础研究发展规划 (G2 0 0 0 0 4680 1);国家自然科学基金项目 (No .499710 0 2and 3 983 0 0 5 0 )资助

摘　　要：根据沿海拔梯度设置的样地的调查资料 ,对南岭东段的莽山和西段的猫儿山植物群落乔木层物种多样性的垂直分布格局进行了比较研究。莽山和猫儿山的植被类型差异不大 ,但相同植被类型的物种组成有比较明显的差异。随海拔的上升 ,两山体乔木的最大树高均呈现显著下降趋势。猫儿山乔木的最大胸径、胸高断面积之和以及立木密度在海拔梯度上呈单峰曲线变化趋势。莽山乔木的最大胸径、胸高断面积之和与海拔呈明显的负相关性 ,而立木密度的变化规律不明显。这种单峰曲线格局或负相关关系与中尺度上的海拔高度以及小尺度上的土壤特性、小地形以及人为干扰强度等因素有关。在海拔 10 0 0m以下的常绿阔叶林群落和 170 0m以上的山顶矮林群落 ,莽山乔木的物种丰富度均明显高于猫儿山。两山体的乔木种数与海拔之间都显示出负相关性 ,但莽山由于高海拔群落受人为干扰的影响 ,这种相关性不显著。乔木层α多样性沿海拔梯度没有表现出明显的变化规律 ,并且在两山体之间也看不出明显的差别。本文最后还对两山脉低海拔区段的常绿阔叶林群落的物种组成和多样性进行了对比分析 ,结果表明人为干扰导致猫儿山常绿阔叶林的物种丰富度 (S)和α多样性 (H′)明显低于莽山的原生性常绿阔叶林群落 ,而且落叶阔叶树种和毛竹We studied changes in floristic composition, community structure and tree species diversity along an altitudinal gradient on Mt. Mang (eastern Nanling Mountains) and Mt. Mao′er (western Nanling Mountains). Floristic composition, but not vegetation type, differed greatly between these two mountains. Maximum tree height decreased sharply with increasing altitude on both mountains. On Mt. Mao′er, maximum DBH, basal area and stem density peaked at intermediate elevations. On Mt. Mang, maximum DBH and basal area showed significantly negative correlations with altitude while stem density did not change significantly with altitude. These unimodal patterns or negative relationships of DBH, basal area and stem density might result from altitudinal gradient at the meso-scale and soil properties, microtopography, and human disturbances at the small scale. Tree species richness on Mt. Mang was obviously higher than that of Mt. Mao′er in the evergreen broad-leaved forests below 1000 m and in brushwoods above 1700 m. On both mountains, species number correlated negatively with altitude, however, this trend was insignificant on Mt. Mang due mainly to human activities at high altitudes. Alpha diversity of tree layer kept stable with increasing altitude and did not differ significantly between these two mountains. Considering tree species composition and diversity of evergreen broad-leaved forests on these two mountains, species richness (S) and α diversity (H′) of the evergreen broad-leaved forests of Mt. Mao′er were lower than those of Mt. Mang. This might stem from human activity and the invasion of many deciduous broad-leaved species and bamboo (Phyllostachys pubescens) on Mt. Mao′er.

关 键 词：物种组成 群落结构 树种多样性 海拔梯度 常绿阔叶林 南岭 植物群落 

分 类 号：Q948[生物学—植物学]