山西七里峪茶条槭的种群结构与空间分布格局

从生命表特征、径级结构、存活曲线及不同海拔种群和不同龄级个体空间分布格局等方面研究了山西七里峪茶条槭的种群结构和空间分布规律.结果显示:(1)七里峪茶条槭种群径级结构呈现幼苗比例大,幼树、小树比例次之的规律,为增长型种群;(2)不同海拔种群中,1 300～1 600m为增长型种群,随着海拔的升高,种群结构逐渐趋于稳定成熟;(3)茶条槭种群的存活曲线接近于Deevey-Ⅲ,除1 400m和1 700m种群外,其它海拔种群存活曲线为Deevey-Ⅱ型;茶条槭种群不同径级的个体呈现出集群分布或随机分布,其空间分布格局随龄级增加而发生改变;(4)不同海拔高度种群的分布格局表现出从集群分布趋向随机分布的规律.研究表明,七里峪茶条槭种群的生活史特征与空间分布具有较为明显的特性,其幼苗储备丰富、自身的生物学特性及种群依存的微环境因素是导致这种现象的主要原因.

Structure and Spatial Distribution of Acer ginnala Population in Qiliyu,Shanxi

Analyzing population structure and spatial patterns of species not only can reveal the dynamic changes and pattern formation mechanism of population,but also can provide the theoretical foundation for local vegetation conservation and restoration.In this study,population structure,life table characteristics and spatial distribution of Acer ginnala population was studied using the life table,size-class structure and survivorship curve.The results showed that:(1)The size-class structure of the population of A.ginnala was a developing population,which majority of the seedling individuals,the saplings and small ones following.On density distribution of size class,the peak appeared in population on DBH<130 cm,after which the density tended to decline.Generally,the density of A.ginnala population decreases gradually with the increases of size class.(2)Within different altitude populations,the population structure was from developing,stability to declining type along the elevation gradient.Life table showed that there was a plenty of seedling individuals in A.ginnala.The peak of mortality rate appeared at different size class in different altitude populations.(3)The survivorship curve of A.ginnala population generally matched a Deevey Type Ⅲ.Except 1 400 m and 1 700 m populations(which matched Deevey Type Ⅲ),other populations’ survivorship curve generally fitted Deevey Type Ⅱ.Spatial distribution patterns of the population differed among growth periods.(4)The distribution pattern was tend to be clumped for seedling,saplings and little tree,but the assemble intensity decreased gradually.Along the elevation gradient,the assemble intensity decreased gradually with the increase of altitude.Overall,there were obvious traits on the life history and spatial structure for A.ginnala.This resulted from A.ginnala’s biological characteristics,abundant seedling resources,microenvironments and interspecies competition.