杭州湾围垦耕地土壤生态系统服务变化特征及阈值分析

Characteristics and Threshold Analysis of Changes in Soil-related Ecosystem Service after Long-term Coastal Reclamation in Hangzhou Bay

研究目的:尝试构建长时间序列下的围垦耕地土壤生态系统服务评估方法体系,通过杭州湾围垦区实证研究,探索围垦耕地土壤生态系统服务的长期变化特征和关键阈值,为存量围垦耕地资源的可持续利用和适应性治理提供参考。研究方法:时空替代法、分段线性回归模型。研究结果:(1)根据土壤生态系统服务理论,构建基于“人类需求—服务类别—关键服务—评价指标”的围垦耕地土壤生态系统服务评价指标体系;(2)由于持续的土壤改良和农业管理措施,围垦耕地土壤生态系统服务显著高于自然滩涂土壤,并随围垦时间延长不断提高;(3)杭州湾围垦耕地土壤生态系统服务对围垦时间的响应呈现显著阈值效应,在围垦后74 a左右,土壤生态系统服务出现“急剧提高—稳定增长”突变特征。研究结论:(1)本文评价体系与方法为沿海围垦耕地评价和耕地保护研究提供了一种新的思路,也为围垦土地的农业生产管理提供有益借鉴;(2)围垦耕地土壤生态系统服务变化具有阶段性,应根据不同围垦年限对围垦耕地采取差异性的管控措施。

The purposes of this paper are to build a soil-related ecosystem service(SES)evaluation framework for cultivated land after long-term coastal reclamation,and to explore the evolution process and key thresholds of SES changes,taking Hangzhou Bay as a case area,so as to provide a reference for sustainable utilization and adaptive governance on the extant reclamation land.The research methods include the space-for-time substitution approach and piecewise linear regression model.The research results show that:1)an evaluation index system of soil ecosystem services in reclaimed cultivated land based on“human needs-service categories-key service-evaluation indicators”is constructed according to the theory of soil ecosystem service.2)The SES of reclaimed cultivated land is significantly higher than that of natural tidal flats,and continues to increase with the extension of reclamation time due to continuous soil improvement and agricultural management measures.3)The response of SES to reclamation time in Hangzhou Bay exhibits a significant threshold effect with a sudden change in the growth rate of SES from fast to slow trend around 74 years after reclamation.In conclusion,this research framework can be applied in the evaluation and protection of cultivated land in coastal reclamation,and also provides the useful reference for agricultural production management.It is recommended to adopt targeted management measures for reclaimed cultivated land according to the reclamation period.