近60年滇池水生态系统演替及驱动因子

Succession and driving factors of Lake Dianchi aquatic ecosystem in the past 60 years

  • 摘要: 滇池流域作为长江上游和我国西南地区生态安全屏障的重要组成部分,对保障区域乃至全国生态安全具有重要作用。采用文献调研、分类梳理等方法,并结合1950—2020年滇池水质变化和富营养化演化过程,系统分析了近60年滇池水生态系统中浮游植物、浮游动物、水生植物、底栖动物、鱼类等重要组成部分的演替过程及驱动因子。结果表明:1960s以前,滇池水体清澈见底,水生生物丰富,处于草型阶段;1970s—1990s,随着滇池富营养化程度加剧,水体理化性质的改变以及水生生物耐营养物种的数量增加,湖泊生态系统由草型阶段向草藻混合型阶段转变;2000—2015年,滇池水质进一步恶化,处于 GB 3838—2002《地表水环境质量标准》Ⅴ类~劣Ⅴ类,水生生物从多优势种向单优势种、清水种向耐污种转变,处于藻型阶段;2016年之后,滇池水质虽逐步改善,但仍面临着严重的富营养化问题。滇池水生态系统演替的驱动因子主要是自然因素、流域污染物排放超出滇池环境容量及生态系统生境片段化。

     

    Abstract: As an essential part of the ecological security barrier in the upper reaches of the Yangtze River and southwest China, Lake Dianchi plays a critical role in safeguarding national and regional environmental security. The succession process and driving factors of phytoplankton, zooplankton, macrophytes, zoobenthos, fish and other essential compositions in Lake Dianchi aquatic ecosystem were systematically analyzed using literature research and classification, combined with the water quality change and eutrophication evolution process of Lake Dianchi in 1950-2020. The results showed that before the 1960s, Lake Dianchi maintained its natural form and belonged to the stage of the macrophyte type lake. Between the 1970s and 1990s, the situation of eutrophication, the physical and chemical properties of the water changed rapidly, and nutrient-tolerant species increased. It indicated that the lake regime shifted from a macrophyte type lake to a macrophyte-algal type lake. From 2000 to 2015, the water environment of Lake Dianchi seriously deteriorated. The water quality was between “Inferior” and “Class V” of Environmental Quality Standards for Surface Water (GB 3838-2002), and the water use function was basically lost, indicating that it belonged to the stage of an algal lake. Since 2016, although the water quality of Lake Dianchi had gradually improved, the eutrophication had remained at a high level. The driving factors of the aquatic ecosystem succession of Lake Dianchi were natural factors, pollutant discharge exceeding Lake Dianchi's environmental capacity, and ecosystem habitat fragmentation. The results could provide important reference values and theoretical support for decision-makers and stakeholders in managing similar shallow lake-water ecosystems.

     

/

返回文章
返回