基于森林景观斑块耦合网络节点关键程度评价方法对比分析

摘要

Based on the forest landscape patches coupling network constructed by using second survey data collected from forest resources of Taoyuan county Changde city,importance of links in the forest landscape patches coupling network is explored and also proper parameters for choosing structural entropy of it are confined.Dimensionality and betweeness are adopted to assess the importance of links toward the same forest landscape patches coupling network taking advantage of software like PAJEK and ARCGIS to work out the degree of importance.Through analysis and comparison of results,it shows that:(1) The method of Betweeness and Dimensionality both indicates the scale-free property of the forest landscape patches coupling network.That is to say,most of the forest landscape patches in the coupling network have little impact on the whole network.There are only a few patches have great influences on the network.If these patches are somehow damaged,the whole network would be crumbled.(2) The two kinds of methods have different emphasis.The method of Dimensionality only assesses the forest from the relations around the links,while the method of betweeness puts more emphasis on the location of the links in the network.Compared with the Dimensionality,the method of the Betweeness is used to comprehensively analyze the effect of the patches on the forest landscapes.This kind of method takes the circulation of material and energy in a whole into consideration,as a result,it accords better with the assessment of the importance of links in the forest landscape patches coupling network.%以常德市桃源县森林资源二类调查数据所构建出森林景观斑块耦合网络为基础,为研究森林景观斑块耦合网络节点关键程度,并为森林景观斑块耦合网络结构熵筛选适合的计算指标,分别选取度数和介数对同一森林景观斑块耦合网络进行节点关键程度评价,利用PAJEK及ARCGIS软件进行计算关键程度计算,通过对计算结果的对比分析,其结果表明:(1)介数法和度值法均反映了森林景观斑块耦合网络的无标度性,即森林景观斑块耦合网络中大多数斑块对于整个网络的影响度较小,只有少数斑块对网络的影响较大,一旦这些影响较大的斑块被破坏,则整个网络将会面临崩溃.(2)2种方法的侧重点不同,度值法仅从节点周围相邻的局部关系来评价,介数法更注重于从节点所处网络的位置来考虑,介数法比度值法更为全面整体的分析了斑块对森林景观的作用大小,考虑到了森林景观整体间的物质能量流通程度,更加符合对于森林景观斑块耦合网络节点关键程度的评价方式.