湖南县域森林资源禀赋空间格局演变分析——一种空间网络模型的构建与验证

Spatial pattern evolution of forest resource endowment in hunan at the county level according to spatial network modeling

研究森林资源禀赋空间格局演变,对森林资源可持续发展具有重要的理论和实践意义。本文从森林资源丰裕程度、生态影响度和物种丰度三个维度对1995年、2005年和2015年湖南森林资源禀赋度进行评价。在此基础上,借助复杂网络理论及Pajek软件,以研究县域行政区划为节点,空间依赖度为边权,构建湖南县域森林禀赋度空间网络,并通过节点的度、介数、聚集系数、形状指数和空间效应强度刻画网络模型的拓扑结构,以此来揭示森林资源空间格局的演变规律。结果显示:冷点区县域单元节点对森林禀赋空间网络的连通作用和影响力要大于热点区节点,热点区县域单元对森林禀赋的空间分布起着正面影响,而冷点区起着负面作用。为进一步优化湖南森林资源空间格局,有效的森林资源调控方式是对存在改善空间(空间效应强度低于0.5)且对整体空间格局影响较大(节点度值在5以上)的研究单元予以重点关注。为进一步揭示森林资源空间分布的规律,未来的研究中应探讨在森林资源演变发展中各节点间作用力的方向,从而找出湖南森林资源空间网络的关键节点和关键边权。

Exploring spatial pattem evolution of forest resources has important theoretical and practical significance for forest resource sustainable development. Based on the degree of forest resource abundance, ecological impact and species abundance, the forest resource endowment degree of Hunan was evaluated in 1995,2005 and 2015. Then, in order to reveal the evolution law of the spatial pattem of forest resources, we used complex network theory and Pajek software for nodal county administrative divisions, spatial dependency as edges, and space network diagrams of endowment degree of forest resources in Hunan. At the same time, degree, betweenness, aggregation coefficient, shape index and spatial effect intensity were used to characterize the topology of the network model. We found that the connectivity and influence of cold spots of complex network were more than hot spots. The hot spots had a positive impact on the spatial distribution of forest resource endowment, but cold spots played a negative impact. In order to promote the spatial collaborative development of forest resources for Hunan, the most effective way is to focus on the research unit of the improvement of the evolution of the composite system （space effect intensity is less than 0.5）and where influence on the overall spatial pattern is larger （node degree value is above 5）. To reveal the law of spatial distribution of forest resources we can study the direction of the interaction between the nodes in the evolution of forest resources in future research to determine key nodes and edge rights of the forest space network.