九寨沟自然保护区油松种群的生命表

The Static Life Table of Pinus tabulaeformis Population in Jiuzhaigou Valley Nature Reserve

油松（Ｐｉｎｕｓｔａｂｕｌａｅｆｏｒｍｉｓ，Ｃａｒｒ．）是九寨沟森林生态系统次生演替的先锋树种之一．本文以九寨沟自然保护区的样地资料为基础，编制了九寨沟不同群落类型中油松种群以径级代替年龄级的生命表来阐明油松种群的结构动态特点．结果表明：①油松林中，油松种群的生存与死亡，死亡密度与危险率存在着波动起伏的特点．生存率与积累死亡率单调下降与上升，下降或上升的幅度是前、后期大，中期平缓．表示种群幼树幼苗死亡率高，老树稀少．种群动态为前期增长，中期稳定，后期衰退．②由于种间竞争，青木千林与落叶阔叶林中，油松种群衰退，幼树幼苗死亡率极高。

Pinus tabulaeformis Carr. is one of pioneer and constructive species in the forests succession series in Jiuzhaigou Valley Nature Reserve.This paper deals with the method of diameter class replacing age class to work out the static life table of P.tabulaeformis population in different communities through field investigation.The results show as follows:①In the Pinus tabulaeformis forest, P.tabulaeformis population has the characteristics of oscillation between surrival and mortality,mortality density and hazard rate.The population was developing in the earlier period,stable in the middle period and declining in the later period.②In the climax communities and pioneer communities, P.tabulaeformis population showed declining because of competition between species with surevival rate being very low.