木林子保护区优势种翅柃种群结构与空间分布格局

Population Structure and Spatial Distribution Pattern of Dominant Species Eurya alatain Mulinzi Nature Reserve,Hubei Province

该研究以湖北木林子保护区优势种翅柃(Eurya alata)为研究对象,编制静态生命表,绘制存活曲线、死亡率和消失率曲线;采用成对相关函数分析各龄级的空间分布特征,双变量成对相关函数分析不同生活史阶段间的空间关系,为阐明木林子保护区常绿落叶阔叶混交林不同构建规律在物种多样性维持机制中的作用提供理论参考。结果显示:(1)翅柃属增长型种群,存活曲线趋于Deevey-Ⅱ型,死亡率和消失率曲线呈单峰型。(2)翅柃Ⅰ~Ⅴ龄级呈现聚集分布且随径级增加而减弱,Ⅵ、Ⅶ龄级在较大尺度上随机分布。(3)在完全随机零模型下,各生活史阶段均呈空间正关联;在先决条件零模型下,成年树与幼树、小树小尺度上呈无关联和负关联,其余生活史阶段间呈正关联,较大尺度上无关联。研究表明,翅柃种群幼树个体丰富,更新状态良好,在自然演替过程中,生境过滤、扩散限制和密度制约均可能驱动种群的构建过程。

In this study,the dominant species Eurya alata population in Mulinzi Nature Reserve of Hubei Province was taken as the research object,and the static life table,the survival curve,the mortality rate curve and the disappearance rate curve were draw up;The spatial distribution characteristics of all age classes were analyzed by pair-correlation function,and the spatial relationships between different life-history stages were explored by bivariate pair-correlation function,which provides a theoretical reference for expounding the role of different construction laws of evergreen deciduous broad-leaf mixed forest in the maintenance mechanism of species diversity in Mulinzi Nature Reserve.Results showed:(1)E.alata population is the growing population;The survival curve tended to be the Deevey-Ⅱtype.(2)The mortality and disappearance rate curves were unimodal.TheⅠ,Ⅱ,Ⅲ,Ⅳ,andⅤage classes of E.alata population showed aggregation distribution and decreased with the increase of diameter grade.Ⅵ,Ⅶage classes appeared to be randomly distributed on a large scale.(3)Under the complete spatial randomness,all stages of life history are positively correlated with range scale.Antecedent condition excludes the habitat heterogeneity,there is no correlation and negative correlation between adult trees and sapling and small trees on a small scale;and other stages of life history are positively correlated on a small scale,but no correlation on a larger scale.The results show that,E.alata population are rich in saplings and in good regeneration state,and in the process of natural succession,habitat filtration,diffusion restriction and density restriction may drive the population construction process.