中全新世以来广西典型红树林群丛林分结构演替对海平面变化的响应：沉积物埋藏红树叶片C、N、O同位素示踪

红树林位于海-陆交界处，因此在全球变化背景下，海平面变化成为制约红树林生态系统变化的关键气候因子；选择有效的示踪参数，重塑历史时期红树林生态系统演化及其与海平面变化的关系是评估未来红树林生态系统命运对海平面上升响应的主要途径之一；红树林群丛林分结构(stand structure)是表征红树林生态系统的主要内涵，其演替与海平面变化制约下的盐度和营养状态变化密切相关，因而成为红树林生态系统演化研究的重要内容。本项目拟以广西典型红树群丛（白骨壤、桐花树、秋茄）分布区（钦州湾和铁山港）柱状沉积物为研究对象，通过其埋藏红树叶片碎屑（sub-fossil）的C、N和O稳定同位素组成的时间变化和协同关系研究，并结合红树孢粉资料，揭示中全新世以来广西典型红树群丛林分结构演替与营养状态和盐度变化的协同关系；结合前人的北部湾全新世海平面变化资料，揭示中全新世广西典型红树林群丛林分结构演替对海平面变化的响应机

Located in the junction between land and sea, the change of mangrove ecosystem is absolutely controlled by sea level change. Reconstruction of the response of historical evolution of mangrove ecosystem to sea level change using valid proxies has been a primary strategy. The stand structure and its relationships to salinity and nutrient dynamics for a given mangrove association are absolutely controlled by sea level change, and thus has become a key topic in the study of mangrove ecosystem evolution. In the present application, the stable isotopes(δ13C,`δ15N andδ18O) of buried leaf sub-fossils in three core sediments raised from Qinzhou Bay and Tieshan Bay, representative of Avicennia marina,Aegiceras corniculatum, Kandelia candel, respectively, will be used as proxies of stand structure evolution of the three mangrove associations and its relationship to salinity and nutrient dynamics,；Following previously established of sea level change of Beibu Gulf, the response of the three mangrove stand structure to sea -level change since the Mid-Holocene will be discussed.