四川省缙云山栲树种群结构和动态的初步研究

A PRIMARY STUDY ON THE STRUCTURE AND DYNAMICS OF CASTANOPSIS FARGESII POPULATION ON JINYUN MOUNTAIN, SICHUAN PROVINCE

栲树(Castanopsis fargesii)是亚热带常绿阔叶林的建群种和优势种之一。本文应用相邻格子样方法和每木调查法进行野外抽样,对缙云山栲树种群的立木级结构和分布格局及其动态特点进行了分析,并探讨了研究长生命期常绿阔叶树种种群的方法问题。结果表明,应用立木级结构代替年龄结构研究栲树种群的结构和动态特征是适用的。立木级结构和存活曲线分析表明栲树种群具有增长型的动态特征。同时应用一次性的调查资料研究了栲树种群的分布格局及其动态特征,显示出栲树种群在其发育过程中,分布格局由集群分布向随机分布变化,而且这种变化是和种群的数量的动态变化有关。引起分布格局发生变化的主要原因是种内及种间竞争所导致的自疏和它疏。

Castanopsis fargesii is one of community species and a dominant species of evergreen broad-leaved forests in the middle subtropics of China. The study of its population is of great significance for studying the forest communities and ecosystems in subtropic China. In this paper, with the 'time specific' method for life-table analysis, the Tree class structure and spatial patterning and their respective dynamic rules of Castanopasis fargesii population on Jinyun Mountain were analyzed. The quadrat method and the technique of censusing every individual are both used in fieldwork. The result shows that the Tree class structure replacing the age structure is suitable for studying the structure and dynamics of Castanopsis fargesii population. The results of the research on the Tree class structure and the survival curve suggest that the Castanopsis fargesii population is characterized by the increasing type. The spatial patterning of the population is of the clump type. However, spatial patterning alters with different Tree classes of the population. It is found that the seedling, sapling and small tree classes show the clump type, while the middle and large tree classes exhibit the random type. This regularity reflects the dynamic change of spatial patterning with time in the development of the population. This change is related to the quantitative dynamics of the population. The chief factors causing this change are the self-thining and the alien-thining cau sed by intraspecific interpecific struggle in the stand.