基于灌木层植物多样性的森林景观斑块耦合网络研究

为了研究西洞庭湖区的森林景观格局及其对灌木层植物多样性的影响，笔者根据西洞庭湖区森林分布，将景观分成12类，通过合并地理位置相邻的同类小班构成景观斑块，利用Shannon-Wiener指数推导出斑块间灌木层边缘效应大小作为边权，建立斑块耦合网络模型，并构建基于灌木层的景观斑块耦合网络。结果表明：景观斑块耦合网络中节点的度呈幂率分布，具有无标度网络和小世界网络特征；节点的度与介数之间满足正相关高阶曲线关系，表明度越大的节点在网络连通中的重要程度越大；林龄大的景观网络，其密度与聚集系数相对较大，网络稳定性越强；从常德林场景观网络中得知，尽管基于灌木层的斑块网络中，单个节点的点强度有正有负，但整个网络的点强度总体呈正值，这种景观格局分布有利于灌木层植物多样性的提高。

Research on the Coupling Network of Forest Landscape Patches Based on Shrubs Diversity

In order to research the forest landscape pattern and its influence on the diversity of shrubs in the west of Dongting Lake, based on the forest distribution, the author divided the landscape into 12 types and constituted landscape plaques by amalgamating adjacent sub-compartment. What’s more, combined with Shannon-wiener index, the author deduced the edge effects of shrubs as the edge weights to establish the model and coupling network. The results showed that the coupling network had both scale-free and small-world characteristics, for it had a power-law distribution of node degrees. The node degree and betweenness had a positive correlating high order curve, which indicated that the higher node degree, the more importance it was in the net’s connection. What’s more, the older the trees, the higher density and clustering coefficients, so that the stronger stability the network was. It could be learned from Changde forest station that the node strength had a positive value in a total, although some of them had either positive or negative value and this type of landscape pattern distribution would promote the diversity of shrubs.