皖南次生马尾松林自然演替进程中的群落动态

Community dynamics in different successional stages of secondary Pinus massoniana forest in south Anhui Province

本研究采用空间替代时间的方法，在安徽牯牛降自然保护区以恢复10、20—30和50a以上的马尾松（Pinus massoniana）林为研究对象，对不同恢复时期群落的物种组成、群落结构、生境因子等进行调查，探明马尾松林演替过程中群落结构变化的动态格局及演替进程中土壤的响应。结果表明：（1）随着演替进程，植物群落物种丰富度逐渐降低，Shannon多样性指数整体呈上升趋势，林冠层落叶树种优势度下降，常绿树种增加。（2）马尾松的径级分布在3个群落中均属单峰型，甜槠（Castanopsis eyrei）的径级分布则由L字型变为逆-J型，其他常绿灌木也呈现出良好的增长趋势。（3）随着演替时间的延长，土壤全N和有机质含量呈上升趋势，pH值表现为下降趋势，土壤肥力随恢复进程而逐渐上升。

To explore successmnal dynamms ot community structure anct associated son response within Pinus rnassoniana forests, species composition, community structure and habitat properties were determined among three forests differing in restoration stages （i. e. , 10, 20-30 and 50 a） in Guniujiang Nature Reserve in Anhui Province, by using a space-for-time substitution approach. The results showed that l） with the succession, the species richness decreased, but the Shannon diversity index increased. The dominance of deciduous trees declined, but the dominance of evergreen trees progressed in the canopy layer; 2） The distribution of diameter size followed the unimodal type for P. massoniana across the three successional stages, but changed from L to inverse-J type for Castanopsis eyrei through forest succession; evergreen shrubs exhibited good performance in growth; 3 ） With the forest succession, soil total nitrogen and organic matter contents increased, and soil fertility increased gradually, while the pH value decreased.