水文情势与盐分变化交互作用对莫莫格湿地植被的影响研究

Climate change and anthropogenic activities have altered regional hydrologic regime and salinity in the Momoge Wetlands. The alteration has caused the large-scale wetland vegetation degradation, which possesses a serious threat to the habitats for white crane, red-crowned crane and other endangered waterfowl species. This project is to assess interactive effects of hydrologic regime and salinity on ecophysiological responses of key wetland plant species, investigate space-time distribution of wetland vegetation succession, and develop an integrated hydrology, salinity, and wetland vegetation dynamic model that is highly applicable and predictable for wetland succession under future hydrologic and salinity changes. Information gained from the research will build a scientific basis for policy making for water and salinity management and restoration and protection of the Momoge Wetlands. At the process level, the project will determine the suitable ecological water level and ecological thresholds to salinity. At the ecosystem level, the project will utilize a combined approach of remote sensing, automated field measurements of water and salinity changes, and high-precision wetland numeric modeling. Upon completion, the project will provide theoretical foundation and new conceptual approaches for ecological recovery of salinity-degraded wetlands on the Songnen Plain.

针对气候变化和人类活动导致的水文情势改变与盐分聚集已造成大面积的莫莫格湿地植被退化，严重威胁到白鹤、丹顶鹤等珍稀水禽的生境现实问题,本项目以湿地恢复和保护需求为导向，认识和理解湿地植被退化的过程与机制为出发点，从微观实验上揭示水文情势与盐分变化交互作用下典型湿地植物生理生态响应机理，确定其适宜生态水位与盐碱生态阈值；宏观层面上进行湿地植被精细遥感调查、样带调查、水盐自动监测和高精度的湿地数字高程模型等技术手段，探索基于水盐过程的湿地植被空间分异规律及生态演替模式，阐释湿地水盐变化-植被响应的相互作用机制；在上述基础上，构建适用性强、精度高的湿地水文动态、盐分变化和植被响应的综合模型，预测未来水文情势与盐分变化情景下湿地演变，为莫莫格湿地水盐管理和植被恢复与保护提供科学依据和决策支持，保障珍稀水禽生境的安全。项目执行将为松嫩平原湿地生态恢复与保护提供理论基础和创新思路，支撑水生态文明建设。

针对气候变化和人类活动导致的水文情势改变与盐分聚集已造成大面积的莫莫格湿地植被退化，严重威胁到白鹤、丹顶鹤等珍稀水禽的生境现实问题,本项目以湿地恢复与保护需求为导向，认识和理解湿地植被退化的生态水文学机制为出发点，从微观实验上揭示水文情势与盐分变化交互作用下典型湿地植物生理生态响应机理，确定其适宜生态水位与盐碱生态阈值；宏观层面上进行湿地植被遥感解译、高精度DEM、样带调查和生态水文要素监测等技术手段，建立了基于水深梯度的湿地植被生态演替模式，在此基础上，构建了基于 EFDC 的白鹤湖湿地水动力模型，模拟了不同降水频率和农田退水量情景下湿地水位的变化，依据白鹤适宜生态水位为调控目标，提出了多情景下白鹤湖湿地生态水文调控对策和措施。通过研究取得的具体成果如下：.（1）扁秆藨草不同生育期对水位和盐度的响应有所不同，对幼苗而言，在研究范围内的适宜生态水位为-5 cm-10 cm，适宜盐碱生态阈值为300 g/L-3000 mg/L；对成株而言，适宜生态水位为30 cm，适宜盐碱生态阈值为300 mg/L-4000 mg/L；芦苇适宜生态水深35-45cm，所能承受的盐碱胁迫阈值为50mM 的NaCl与25mM 的NaHCO3的混合胁迫，单纯的盐胁迫阈值为50mM 的NaCl，单纯的碱胁迫阈值为100mM 的NaHCO3。.（2）获取了白鹤适宜生境需求条件，适宜的生态水深30-50 cm，适宜的水面面积为 2600 ha。.（3）针对不同水文年（丰、平、枯）和农田退水量，以白鹤湖生境需求的生态水位为调控目标，提出了多情景下白鹤湖水文调控对策与措施。.研究成果对松嫩平原湿地生态水文恢复与调控具有重要理论指导意义，也可为吉林西部河湖连通工程水资源调度和管理提供科学依据。