Huang Aiping, Liu Xiaobo, Peng Wenqi, Dong Fei, Han Zhen, Du Fei, Ma Bing, Wang Weijie
State Key Laboratory of Simulation and Regulation of River Basin Water Cycle, China Institute of Water Resources and Hydropower Research, Beijing 100038, China.
State Key Laboratory of Simulation and Regulation of River Basin Water Cycle, China Institute of Water Resources and Hydropower Research, Beijing 100038, China.
Sci Total Environ. 2023 Dec 20;905:167831. doi: 10.1016/j.scitotenv.2023.167831. Epub 2023 Oct 13.
The inundation pattern is an important ecohydrological indicator for studying floodplain lake wetlands, as it is the key factor affecting the wetland vegetation distribution patterns. Poyang Lake, the largest freshwater lake in China, is a typical floodplain lake wetland. This study presents a hydrodynamic model and vegetation survey of Poyang Lake, analyzed the spatiotemporal heterogeneity of the inundation pattern (inundation duration and depth), assessed the response patterns of wetland vegetation concerning the inundation pattern, and examined the impact of the proposed Poyang Lake Water Conservancy Hub (PLWCH) on the inundation pattern and wetland vegetation. The results revealed that the inundation pattern of Poyang Lake had significant spatial heterogeneity. Inundation pattern was found to have a significant impact on the vegetation succession. The response relationship between the distribution areas of different wetland vegetation types and inundation pattern was in accordance with the Gaussian curve, and the ecological threshold range of the Carex spp. community was the greatest. Owing to factors such as climate change and anthropogenic activities, the inundation pattern of Poyang Lake varied significantly since 2003, with the average inundation duration and average inundation depth decreasing by 15 d and 0.32 m, respectively. Consequently, the spatial distribution of wetland vegetation changed significantly, whereby the Carex spp., Polygonum criopolitanum, and Phalaris arundinacea communities extended down to the lower elevation zone. In the future, the PLWCH may result in increases in the inundation duration and depth, restrain the downward vegetation extension trend, and promote the vegetation to move to higher elevations similar to the status prior to 2003. These findings provide a detailed description of the spatiotemporal heterogeneity of the inundation pattern and the drivers of wetland vegetation distribution patterns in floodplain lake wetlands, serving as a scientific basis for conservation and restoration of these ecosystems.
淹没模式是研究河漫滩湖泊湿地的一个重要生态水文指标，因为它是影响湿地植被分布格局的关键因素。中国最大的淡水湖鄱阳湖是典型的河漫滩湖泊湿地。本研究提出了鄱阳湖的水动力模型和植被调查，分析了淹没模式（淹没持续时间和深度）的时空异质性，评估了湿地植被对淹没模式的响应模式，并研究了拟建的鄱阳湖水利枢纽（PLWCH）对淹没模式和湿地植被的影响。结果表明，鄱阳湖的淹没模式具有显著的空间异质性。发现淹没模式对植被演替有显著影响。不同湿地植被类型分布面积与淹没模式的响应关系符合高斯曲线，苔草属群落的生态阈值范围最大。由于气候变化和人类活动等因素，自2003年以来鄱阳湖的淹没模式发生了显著变化，平均淹没持续时间和平均淹没深度分别减少了15天和0.32米。因此，湿地植被的空间分布发生了显著变化，苔草属、蓼子草和虉草群落向下延伸至较低海拔区域。未来，PLWCH可能导致淹没持续时间和深度增加，抑制植被向下延伸趋势，并促使植被向更高海拔移动，类似于2003年之前的状态。这些发现详细描述了河漫滩湖泊湿地淹没模式的时空异质性以及湿地植被分布格局的驱动因素，为这些生态系统的保护和恢复提供了科学依据。
