浑善达克沙地榆树种群结构、格局及动态研究

Dynamics,Patterns and Structure of Major Population in Ulmus pumila var. sabulosa Sparse Forest in Hunshandake Sandland

以浑善达克沙地榆疏林为研究对象,研究了沙地榆疏林种群结构、分布格局与动态特征。结果显示:①丘间低地沙地榆种群呈衰退型种群。固定沙丘沙地榆种群呈增长型种群;②沙地榆种群总体分布格局呈聚集分布,都随着尺度的增大,聚集强度呈减小的趋势;③种群空间分布动态分析表明,丘间低地沙地榆种群,幼、中树随着立木级增大其聚集强度逐渐减弱,大树则在5 m×5 m尺度上呈现出随机分布;固定沙丘沙地榆种群,小、中树随着立木级的增大其聚集强度呈现逐渐增强的趋势,而大树则在10 m×10 m的尺度上呈现出随机分布。物种分布格局主要与物种本身的生物生态学特性和生境有关,育林作业面积应不低于25 m2。

In Hunshandake sandland, the dynamics, patterns and structuresof major populations in Ulmus pumila var. sabulosa sparse forest were studied. The results showed： （1） Populations in Ulmus pumila var. sabulosa on the inter-dunes lowland presented declining type, and that in the fixed sand dune had abundant sapling and young trees, and presented increasing type; （2）Spatial distribution patterns of populations in Ulmus pumila vat. sabulosa presented aggregated distribution, and the congregated intensity presented decreasing trend along with scale increasing. （3）For populationsin Ulmus pumila var. sabulosa on the inter-dunes lowland in differently congregated intensity scales, themid trees and sapling presented decreasing trend along with pyramids of tree class increasing, and big tree presented a random distribution on plot size of 5m×5m. （4）The congregated intensity of mid tree and young trees of populations in Ulmus pumila var. sabulosa on the fixed sand dune at differently scalespresented increasing trend along with pyramids of tree class increasing, and big tree presented a random distribution on plot size of 10 m×10 m. This distribution patterns of the species are mainly related to their ecological and biological characteristics and habitat, and the managing area must be not lower than 25 m2.