震后生态恢复初期植被?土壤的耦合关系研究

  目的  探究汶川地震重灾区不同气候区恢复初始阶段植被与土壤的耦合协调关系，为促进灾害干扰地区的生态恢复和植被?土壤系统的协调发展提供参考依据。  方法  以干旱河谷气候区、亚热带季风性气候区的受损治理区和未受损区（AT和AU、ST和SU）为研究对象，测定植被和土壤的21个指标，采用主成分分析法得出两个气候区4种生态系统的主要影响因子和21个指标的权重，并构建对应的植被?土壤耦合协调度（D）模型。  结果  SU的植被、土壤综合指数和D均显著高于其他3种植被?土壤系统。AT和ST均为初级协调发展类土壤滞后发展型，AU和SU分别为初级和中级协调发展类植被土壤同步发展型。干旱河谷气候区的影响因子较为单一，AT的主要影响因子为土壤有机碳、全氮、速效氮和速效磷，AU为植物碳、氮、钾和镁。亚热带季风性气候区的影响因子表现为植被?土壤影响因子共存，ST的主要影响因子为物种丰富度、生物量、土壤全氮和速效氮，SU为植被覆盖度、植物磷、土壤速效钾和细菌。  结论  气候和生态恢复类型对植被?土壤耦合状况具有一定的影响。SU的植被?土壤耦合状况显著优于其他3种生态系统。AT和ST的土壤环境均较差，经7年治理尚未恢复到震前水平。 

Coupling relationship between vegetation and soil in the early stage of ecological restoration after earthquake: a case study of Weizhou Town in Wenchuan County and Hanwang Town in Mianzhu City of Sichuan Province,southwestern China

  Objective  Studying the coupling and coordination relationship between vegetation and soil in the early stage of restoration in different climate regions of the Wenchuan earthquake-affected areas can provide a basis for promoting the ecological restoration and the coordinated development of vegetation-soil system in the disaster disturbed area.  Method  In this study, the treated area and undestroyed area of the arid-valley climate region and the subtropical monsoon climate region (AT and AU, ST and SU) were selected as the research objects. We measured twenty-one indexes covering plant and soil, analyzed the main influencing factors and the weights of twenty-one indicators of the four ecosystems in the two climate regions by principal component analysis, and constructed the corresponding model of vegetation-soil coupling coordination degree.  Result  SU’s D, comprehensive indexes of vegetation and soil were all significantly higher than the other three vegetation-soil systems. AT and ST were both soil lagging development type of primary coordinated development, AU and SU were synchronous development type of vegetation and soil of primary and intermediate-level coordinated development, respectively. The influencing factors of the arid-valley climate region were relatively simple: the main influencing factors of AT were soil organic carbon, total nitrogen, available nitrogen and available phosphorus, and those of AU were plant carbon, nitrogen, potassium and magnesium. The influencing factors of the subtropical monsoon climate region were vegetation-soil influencing factors coexisting: the main influencing factors of ST were species richness, biomass, soil total nitrogen and available nitrogen, and those of SU were vegetation coverage, plant phosphorus, soil available potassium and bacteria.  Conclusion  The climate and type of ecological restoration had certain influence on the coupling status of vegetation and soil. The coupling status of vegetation-soil in SU was significantly better than the other three ecosystems. The soil environments of AT and ST were both poor, indicating that nutrient condition of treated areas did not recover to the pre-earthquake level after treatment for seven years.