河北滨海湿地生态系统对长期气候变化与人类活动的响应

滨海湿地作为海陆过渡型生态系统，具有多重生态价值，因其特殊的水文、植被和土壤特征而对人类活动和气候变化响应敏感。探究典型滨海湿地生态系统对气候变化和人类活动的响应特征及机制，对准确预测与评估其未来景观环境和生态服务功能变化至关重要。目前我国北方有关滨海湿地生态系统（特别是生物组分）对长时间气候变化和人类活动的响应研究还较为薄弱。本项目拟选择河北典型滨海湿地（七里海、曹妃甸和南大港）作为研究区域，基于不同时间尺度沉积记录及精确定年，以孢粉、植硅体和硅藻等生物指标为主，结合理化指标和历史文献，揭示其生态系统关键生物组分对全新世气候特征时段、极端气候事件以及历史时期人类活动的响应特征及机制；识别和评估近代以来滨海湿地生态系统稳态转换过程与弹性变化，并分析其主要驱动机制，以确定合理的生态阈值。为预测未来增温背景下河北滨海湿地的环境脆弱性和生物多样性的变化提供重要理论证据。

As a transitional ecosystem between land and marine, coastal wetland generally has multiple significant ecological values. Due to their special characteristics of hydrology, vegetation, and soil, coastal wetlands are very sensitive to human activities and climate change. Exploring the response characteristics and mechanisms of typical coastal wetland ecosystem to climate change and human activities is crucial for accurately predicting and evaluating the changes of their landscape environment and ecological service functions in the future. However, at present, studies on the response of coastal wetland ecosystem (especially its biological components) to the long-term climate change and human activities are still rare in northern China. This project plans to select several typical coastal wetlands in Hebei Province (including Qilihai, Caofeidian, and Nandagang) as the study areas. Based on the sedimentary records (mainly the biological indicators such as pollen, phytolith, and diatom, combining with physical and chemical indicators) of different time scales and the precise determination of chronology, as well as the historical literature, we intend to: reveal the response characteristics and mechanisms of key biological components of the coastal wetland ecosystems to the climatic characteristic periods and the extreme climate events during the Holocene, as well as the human activities in different historical periods; and to identify and evaluate the regime shift process and the resilience change of coastal wetland ecosystem since modern times, and to analyze the main driving factors for determining a reasonable ecological threshold. Finally, this project will provide an important theoretical basis for predicting the environmental vulnerability and the biodiversity change of coastal wetlands in Hebei Province under the background of global warming in the future.