重庆缙云山不同龄级植物种群生态位宽度研究

Studies on Niche Breadth of Plant Populations at Different Age Groups in Jinyun Mountain,Chongqing

对缙云山森林植被的 4个优势种群 3个年龄级生态位宽度进行了研究 .结果表明 ,川灰木利用资源的能力最强、分布广 ,为典型的泛化种 .大头茶、栲树、马尾松对资源的利用在一定程度上特化 ,分布上有一定的局限性 .马尾松的中龄组与幼龄组特化现象十分显著 .缙云山森林植被的先锋种马尾松的发展 ,导致环境的改变不适于其幼龄个体的生长 ,群落演替到针阔叶混交林阶段 ,最后发展为以栲树等为建群种的常绿阔叶林 .种群的资源利用能力 ,是种群分布与群落演替的内在原因 ,光因子和营养元素 (如N)

Niche breadth of four dominate populations at three age groups was studied by the methods of resource utilization ability and ratio.The result shows that:Symplocos sectchuanensis is a typical gengeration species which resource utilization ability is strong,and distribution is wide.Meanwhile,Gordonia acuminata,Castanopsis fargesis and Pinus massoniana specialized at some degree in resource utilizationm,their distribution is limited.Especially,the juvenile of Pinus massoniana specialized outstandingly.With the devlopment of Pinus massoniana,which is the pioneer population in Mt.Jinyun,the environment becomes unfit to it's juvenile.It turns to needle and evergreen broad leaves mixed forest.Because the tolerance toward shading of Gordonia acuminata is lower than that of Castanopsis fargesis,Gordonia acuminata will be substituted by Castanopsis fargesis and other evergreen broad leaves species are the edificators.The population's ability of resource utilization is the inner factor of population distribution and community succession.The distribution of light and the concentrate of nutrient(such as N)is the outer factors of community succession.