摘要
当前我国湖泊污染及富营养化问题非常严重。湖泊治理的一个有效途径就是恢复水生植物,通过草型湖泊生态系统的培植来达到控制富营养化和净化水质的目的。但是,迄今为止,只有在局部水域或滨岸地区获得成功,恢复的水生植物主要是挺水植物或漂浮植物。鲜有全湖性的水生植物恢复和生态修复成功的例子。原因是对湖泊生态系统退化及其修复的机理了解甚少。实际上,环境条件不同决定了生态系统类型的不同,只有通过环境条件的改变才能实现生态系统的转变。利用草型湖泊生态系统来净化水质,其实质是利用生态系统对环境条件的反馈机制。但是,这种反馈无法从根本上改变其环境条件,因此其作用是有限的,不宜过分夸大。以往许多湖泊生态修复的工作之所以鲜有成功的例子,原因就是过于注重水生植物种植本身,而忽视了水生植物生长所需的环境条件的分析和改善。实施以水生植物恢复为核心的生态修复需要一定的前提条件。就富营养化湖泊生态恢复而言,这些环境条件包括氮磷浓度不能太高,富含有机质的沉积物应该去除,风浪不能太大以免对水生植物造成机械损伤,水深不能太深以免影响水生植物光合作用,鱼类种群结构应以食肉性鱼为主等等。因此,在湖泊污染很重或者氮磷负荷很高的情况下,寻求以沉水植物为核心的湖泊生态恢复来改善水质是不切实际的。为此,提出湖泊治理应该遵循先控源截污、后生态恢复,即先改善基础环境,后实施生态恢复的战略路线。
Lake pollution and eutrophication have become an important issue in China. Re-establishing macrophyte dominance is thought to he an effective method for eutrophication control and improving water clarity. To date, few cases of lake restoration have been successfully implemented in China. One reason is that lake restoration is often limited to aquatic vegetation planting, and changes in environmental conditions were not evaluated and implemented. Lake restoration practices emphasizing macrophyte restoration without fully understanding relationships, between macrophyte growth and environmental conditions are incomplete and short-sighted. In fact, lake ecological restoration requires knowledge of existing environmental conditions. If environmental conditions determine the ecosystem type, then changes in environmental conditions should be emphasized for understanding ecosystem shifts. For a lake ecosystem shift from algal- to macrophyte- dominated systems, these environmental conditions include weak wind-induced waves, high transparency, low nutrient loadings, a decrease in plankti-benthivorous fish and Lake macrophyte restoration is seldom successful when increase in predatory fish, removal of organic-rich sediment, etc nutrient loading is still high. Therefore, lake restoration must be conducted subsequent to control of nutrient loading, i.e. control the input of pollutant first, then attempt ecological restoration.
出处
《生态学报》
CAS
CSCD
北大核心
2007年第11期4848-4858,共11页
Acta Ecologica Sinica
基金
国家自然科学基金重点资助项目(40730529)
中国科学院知识创新方向性资助项目(kzcx2-yw-419)
国家十五"863"重大水专项资助项目(2002AA601011)~~
关键词
湖泊生态恢复
水生植物
环境改善
lake ecosystem shift
macrophyte
environmental conditions
