云南松种群结构与数量动态研究

采用“空间差异代替时间变化法”和“样地编年序列法”，探讨山地云南松种群的结构与数量动态，结果表明：种群演替方向和动态特征与其所处坡位密切相关，山脊种群密度呈先升后降再回升的趋势．种群结构经过增长、稳定和衰退之后恢复为增长型，种群生物量保持缓慢增长；山坡中部种群密度经过上升之后缓慢下降，种群结构经过增长、稳定之后转变为衰退型，但种群密度和生物量维持在一定水平；山坡下部种群密度经过增长之后迅速下降，种群结构经过增长和稳定之后转变为衰退型，种群密度和生物量保持在很低水平。故山脊种群将保持其在群落中的优势地位，山坡中部形成针阔混交林，山坡下部云南松种群被常绿阔叶林所替代。但云南松种群在不同演替阶段的空间分布格局也有一定差异，总体趋势是随着演替进展由集群型向随机型转变。

Study on the Structure and Density Dynamics of Pinus yunnanensis Population

The structure and dynamics of Pinus yunnanensis population were analyzed by using the method of spatial series substitution for time series and plots arranged with age. The result showed that the orientation of population succession and dynamic characteristics were closely related to the locations on the slopes. The population density on the ridgeline changed in an up-down-up model and resumed to be up-growth type after the course of growing, stabilizing and declining, and the population biomass increased slowly. The population density on the mid slopes increased first and declined steadily afterwards and the population structure became degraded, while the population density and biomass would maintain at a certain level. On the lower part of the slopes, the population density dropped quickly after an increasing phase, the population structure became declining after an increasing and stabilizing stages respectively, then the population density and biomass maintained at quite low levels. The results indicated that the P. yunnanensis population on the ridgeline would retain its predominant status in the community; the community on the mid slopes would be mixed forest composed of coniferous and broad-leaved tree species; and the population of P. yunnanensis would be often substituted by broad-leaved tree species at the lower part of the slopes. The study also indicated that there was difference in the spatial distribution pattern of P. yunnanensis populations in different phases although the general succession tendency was to be random distribution type from the aggregative type.