【摘要】 本文分析了五种天然次生林群落类型的年龄结构及其动态变化规律。指出它们均具有一定程度的异龄性,次生林的异龄性程度随其所处演替阶段的不同而异,树木年龄与地径的关系及群落中树木年龄与株数的关系可以用不同的数学模型来模拟。研究表明,山杨,白桦的年龄结构呈比较明显的衰退型趋势;胡桃楸、水曲柳则呈增长型的趋势;蒙古栎种群的年龄结构金字塔与稳定型的年龄结构相近,但亦有一定的增长型特征。对天然次生林群落的年龄结构的研究,可以为次生林的合理经营及收获调整,提供重要的理论依据。更多还原

【Abstract】 The age structures and dynamics of five types natural secondary forests were analysed in this paper. The research revealed that they are all uneven-aged to some extent. The degree of uneven- age varies with the succession stage. The relationship between the age of tree and the root diameter as well as the relationship between the age of tree and the number of the trees in commun- ity can be imitated with different mathematics models. The age structures of popula and birch populations are delined types, and those of manchurian walnut and manchurian ash are increased types. The age-pyramid of mongolian oak is stable type, but has some characteristics of increased type. The research on the age structure of natural secondary forest community, may provide some important theoretical base for the rational management and yield regulation of secondary forest.更多还原