结合生态系统过程模型及生态位理论分析气候变化对东北沼泽湿地碳汇功能影响

The crucial impacts of climate change are main driving forces in inland wetlands transformation and reduction and have become the front of relational subjects and the focus of science studies. The Northeast China is one of the most sensitive and vulnerable areas suffering intense climate change impacts. Since 1950, the warming has accelerated during recent decades, which is a main driving factor for water shortage in wetland area. At the same time, the annual precipitation of the Northeast China decreased, and there were temporal and spatial differences, with some areas having larger decreases, and others, less decreases. Based on literature meta-analysis, historical survey data, meteorological data and remote sensing, this project aims to reveal relationships between climate factors and wetlands changes of 1980, 1990, 2000 and 2015. This project plans to estimate depth by using manual probing and ground-penetrating radar (GPR), and then evaluate carbon storage accurately. By comparative analysis between the data collected in field and historical wetlands survey data, this project plans to revealing the effect warming and water fluctuation on carbon accumulation rate and storage. Based on those results, the climatic and environmental variables which are important measures of the distribution of wetlands will be evaluated and selected. To test all niche-based habitat distribution models predictive performance, Area under the Curve (AUC), Kappa (K) and True Skills Statistics (TSS) will be used to measure model accuracy. The more accurate niche-based habitat distribution models will be elected. And combining with Wetland-DNDC and investigation of plant biomass, this project plan to assess the potential impacts of climate change on distribution and carbon sink function of typical wetlands and carbon storage under 4 IPCC scenarios (RCP 2.6, RCP 4.5, RCP 6.0 and RCP 8.5) for 3 periods in the future (2020s, 2050s and 2080s). Results of this project will be important to a deeper appreciation of carbon storage capacity of wetlands affected by climate change, and are with guidance significance to valid police establishment and conservation of the wetlands within northeast China.

气候变化是导致全球沼泽湿地减少的主要驱动因素，其影响亦是当前沼泽湿地研究领域热点。东北地区是我国主要沼泽湿地分布区，也是气候变化显著地区之一。1950至今，东北地区年均气温显著上升，降雨时空变率增大，致使沼泽湿地萎缩且功能退化。本项目拟利用调查资料和遥感技术，建立东北地区沼泽湿地历史与现状空间数据库，结合气候数据解析沼泽湿地空间分布对气候变化的响应机理；利用先进测地雷达技术与剖面采集，精确测定沼泽湿地土壤深度、含碳量等参数，分析气候变化对沼泽湿地土壤碳储量、累积速率的影响；在此基础上，分析气候因子和环境因子对各类沼泽湿地分布的影响程度，利用生态位分布模型模拟并分析未来气候情景下典型沼泽湿地的潜在分布区及其时空变化过程；结合湿地过程模型评估气候变化对其碳累积速率的影响，预测沼泽湿地在未来的固碳潜力和风险。研究结果对深入了解气候变化对东北沼泽湿地潜在影响以及制定适应性对策具有重大意义。

气候变化是导致全球沼泽湿地减少的主要驱动因素，其影响亦是当前沼泽湿地研究领域热点。东北地区是我国主要沼泽湿地分布区，也是气候变化显著地区之一。1950至今，东北地区年均气温显著上升，降雨时空变率增大，致使沼泽湿地萎缩且功能退化。本项目利用调查资料和遥感技术，建立了东北地区沼泽湿地历史与现状空间数据库，结合气候数据解析了沼泽湿地空间分布对气候变化的响应机理；利用土壤剖面数据，精确获取了沼泽湿地土壤深度、含碳量等参数，分析了气候变化对沼泽湿地土壤碳储量、累积速率的影响；在此基础上，分析了气候因子和环境因子对各类沼泽湿地分布的影响程度，利用生态位分布模型模拟并分析了未来气候情景下典型沼泽湿地的潜在分布区及其时空变化过程，还原了东北地区全新世中期（约6000年前）沼泽湿地分布情景；结合资料同位素定年数据，评估了气候变化对其碳累积速率的影响，并预测了气候变化对沼泽湿地未来固碳能力的潜在影响。本研究的研究结果对深入了解气候变化对东北沼泽湿地潜在影响以及制定适应性对策具有重大意义。