湖泊生态系统稳态转换理论与驱动因子研究进展

摘要

The lake ecosystem can undergo regime shifts triggered by long-term human threats and short-term strong disturbance. Before and after regime shifts, the ecosystem structure and key processes will change dramatically. For scientific management and decision making on lakes, it is therefore essential to reveal the mechanism and explore the driving factors of regime shifts. We concluded and discussed the concept and driving factors of regime shifts. Changing dramatically and difficult to forecast, ecosystem structure and key processes change, alternative stable state are main connotations of the concept of regime shifts. The characteristics of regime shifts include non-linear, alternative stable state, multiple thresholds, and hysteresis during restoration. There are external and internal factors in driving shifts between alternative states. The external driving factors include external nutrient loadings, climate change, storm, and water level. The influence of external nutrient loadings and climate change on lake ecosystem are long-term and accumulative. They can weaken the ecological resilience of lake to trigger regime shifts. Storm and water level are short-term factors and can trigger regime shifts shortly. The internal driving factors include fish, macrophyte. Fish can impose influence on macrophyte, lake sediment and zooplankton to trigger regime shifts. There is not only positive feedback effect of macrophyte on clear state of lake, also under certain conditions there is negative feedback effect. Some potential research focus was proposed based on the intensive literature review, including: (a) integrated influence of environmental and biological factors on macrophyte, (b) dominated states and key processes controlling the state based on large scale lake survey.%湖泊生态系统会在长期的人为胁迫和短期的强扰动下发生稳态转换，稳态转换前后湖泊生态系统的结构和关键过程会发生明显的变化，探求浅水湖泊稳态转换驱动因子是科学合理确定湖泊管理策略的关键所在。对湖泊生态系统稳态转换的理论内涵、驱动机制进行了总结和探讨。湖泊生态系统稳态转换的概念主要含有发生的突然性和难以预知性、系统的结构与功能发生明显变化以及存在多稳态现象等内涵；具有非线性、多阈值、多稳态，以及修复过程中的迟滞效应等特征。湖泊生态系统稳态转换的驱动因子可分为外部驱动和内部驱动两种类型。外部驱动包括外源性氮磷负荷、气候变化、风浪、湖泊水位等因子；外源性氮磷负荷和气候变化的影响具有长期性和累积性，通过逐步削弱湖泊生态系统恢复力进而引发稳态转换；风浪、湖泊水位等为突发性因子，往往表现为稳态转换的直接诱因。内部驱动包括鱼类、水生植物等因子；鱼类主要通过对水生植物、湖泊底质、浮游动物等生态组分的影响引发湖泊生态系统稳态转换；水生植物对湖泊清水稳态可能不仅存在正反馈作用，也会在一定条件下存在负反馈作用。今后应加强沉水植物生长消亡的主要环境与生物要素综合作用机理、湖泊稳态类型与主控因素等方面的研究。