Research Center of Aquatic Organism Conservation and Water Ecosystem Restoration in University of Anhui Province, College of Life Science, Anqing Normal University, Anqing 246133, China.
Research Center of Aquatic Organism Conservation and Water Ecosystem Restoration in University of Anhui Province, College of Life Science, Anqing Normal University, Anqing 246133, China.
Sci Total Environ. 2022 Mar 20;813:151860. doi: 10.1016/j.scitotenv.2021.151860. Epub 2021 Nov 23.
Aquatic vegetation in lakes along the middle and lower reaches of the Yangtze River has been seriously degraded by human disturbances such as river-lake disconnection and water eutrophication. Chaohu Lake is a typical lake with reservoir-like water-level fluctuations (WLFs). Since a sluice was built in 1962, the coverage of aquatic vegetation in Chaohu Lake has been very low (0.77%). In this study, field investigations of the aquatic vegetation and seed bank of Chaohu Lake were conducted, and aboveground vegetation diversity was found to be low. Forty-eight species were recorded, of which submerged, floating-leaved, and emergent macrophytes were 1, 5, and 10, respectively. Currently, artificially planted Phragmites australis and Salix communities have become the main community types. A total of 18 aquatic macrophytes were identified in the seed bank, of which the number of submerged, floating-leaved, and emergent macrophytes and hygrophytes were 2, 2, 3, and 11, respectively; the seed density was 2.05, 2.05, 16.93, and 9.30 ind./m, respectively. The seed density of aquatic macrophytes was much lower in Chaohu Lake than in the lakes with quasi-natural WLFs, and the seeds were mainly distributed in the estuary area. Only two emergent macrophyte species (Typha) germinated in the open water area. Spearman correlation analysis showed that the distance to bank was the main environmental factor that affected aquatic macrophyte diversity and seed density in the seed bank. It is not feasible to promote the natural reconstruction and restoration of aquatic macrophytes in Chaohu Lake by decreasing the water level or increasing water transparency, but the area near the estuary can be identified as a priority restoration area (PRA) for aquatic macrophytes. Artificial transformation of the micro-topography can be used to guide some hydrochorous seeds in the tributaries to the PRA and restore aquatic vegetation in the local area.
沿长江中下游地区的湖泊中的水生植被受到了诸如河湖断流和水体富营养化等人类干扰的严重退化。巢湖是一个具有典型水库型水位波动（WLF）的湖泊。自 1962 年建造水闸以来，巢湖的水生植被覆盖率一直很低（0.77%）。本研究对巢湖的水生植被和种子库进行了实地调查，发现地上植被多样性较低。共记录了 48 种植物，其中沉水、浮叶和挺水植物分别为 1、5 和 10 种。目前，人工种植的芦苇和柳树群落已成为主要的群落类型。种子库中共鉴定出 18 种水生植物，其中沉水、浮叶和挺水植物和湿生植物的数量分别为 2、2、3 和 11；种子密度分别为 2.05、2.05、16.93 和 9.30 ind./m。巢湖的水生植物种子密度远低于具有准自然 WLF 的湖泊，种子主要分布在河口区。只有两种挺水植物（香蒲）在开阔水域中发芽。Spearman 相关分析表明，距岸距离是影响种子库中水生植物多样性和种子密度的主要环境因素。通过降低水位或增加水透明度来促进巢湖水生植物的自然重建和恢复是不可行的，但可以将河口附近区域确定为水生植物的优先恢复区（PRA）。人工改造微地形可用于引导支流中的一些水生种子进入 PRA，并恢复当地的水生植被。
