中国南海北部不同岛屿植被与土壤的耦合协调发展度

植被和土壤是陆地生态系统两个重要的组成部分，二者相互影响相互促进，探明两者的耦合协调关系是生态恢复与重建的顺利实施的关键。基于中国南海北部大庙墩岛、涠洲岛、大汉三墩岛、甘蔗岛和蜈支洲岛等个海岛的典型植被群落植被土壤的全面调查和取样分析，建立10个植被因子和14个土壤因子的2级层次指标体系，采用层析分析法确定各因子的权重，构建5个海岛植被土壤耦合度和耦合协调度模型。结果表明，不同岛屿的植被土壤耦合度和耦合协调度模型并不完全对应，植被与土壤的综合指数在不同岛屿中也不完全一致，甘蔗岛的植被效应和大汉三墩岛的土壤效应最佳。中国南海北部5个岛屿的植被土壤耦合协调状况较好，均处于初、中级协调发展状态，且除甘蔗岛外处于植被土壤同步型。总的来说，由于岛屿远离内陆，人类干扰相对较小，在植被土壤长期的演替过程中，中国南海北部岛屿植被土壤耦合协调较好，在其恢复与生态重建时要注重提高植物多样性、抚育水平和土壤管理水平。

Coupling coordinative degree of vegetation and soil in different islands in the north of South Sea, China

Vegetation and soil are two important components of the terrestrial ecosystems. There is to some extent an interaction between vegetation and soil systems and they influence each other. Therefore, exploring the coupling coordinative relationship between vegetation and soil could be the key to successful implementation of ecological restoration and reconstruction in the terrestrial ecosystems. The islands of the South Sea in China are located on the edge of the world''s largest tropical-subtropical shelf, which are an inalienable part of China''s territory. Due to clear boundaries and isolation from the land, islands are faced with problems such as strong habitat heterogeneity, lack of plant germplasm resources and fresh water, large evaporation, and so on. They are special and independent ecosystems which are more vulnerable to extreme climates or natural disasters such as typhoons, and become easily degraded but difficultly to be restored. This paper is based on the comprehensive investigation and systematic determination between vegetation and soil systems in the typical vegetation communities on five islands in the northern South Sea, China, i.e., Damiaodun Island, Weizhou Island, Dahan Sandun Island, Ganzhe Island, and Wuzhizhou Island. The two-level index system combined with 10 vegetation factors and 14 vegetation factors were established to determine the weight of each factor by the analytic hierarchy process, and then to build coupling models and coupling coordination models of vegetation and soil systems in the five islands. The results showed that the vegetation-soil coupling models and coupling coordination models in different islands were not completely corresponding. In addition, the comprehensive indexes of vegetation and soil were not completely consistent in each island. The vegetation effect of Ganzhe Island and the soil effect of Dahansandun Island were the best, respectively. The coupling coordinative status of vegetation and soil was good in the five islands in the northern of South Sea, China, which were in a state of primary or intermediate coordinated development. All the islands were in the synchronization type of vegetation and soil except Ganzhe Island. In general, due to islands far from land with relative small human interference, during the long-term succession of vegetation and soil, the coupling coordination between vegetation and soil systems in the northern islands of the South Sea of China was in a good status. Therefore, special attention should be paid to improve plant diversity, tending level, and soil management level during the process of vegetation restoration and ecological reconstruction in the northern islands of the South Sea of China.