大坝的生态效应:概念、研究热点及展望

大坝产生的生态效应涉及范围广、周期长,在对社会经济发展起到积极作用的同时,也对生态、环境造成了一定的影响。在评述国内外对大坝生态效应概念和内涵理解的基础上,提出了大坝生态效应链和生态效应网的概念。依据大坝建设和运行的特点,结合流域生态系统的特征分别论述了大坝对水文、局地生态的调节效应以及屏障效应和岛屿化、截留效应、边缘效应、水温效应等国内外研究的热点。最后,提出了今后大坝生态效应的研究方向:1)生态正效应、生态效应链和生态效应网;2)生态系统过程和状态生态效应;3)不同时空尺度下生态效应及其尺度推绎方法等3个方面的研究。

Ecological effects of dam: Concepts, research hotspots and prospects

Despite of the significance in energy supply and society-and economy development,dam has been vehemently criticized because of its various ecological and environmental effects,especially the negative ones.The ecological effects of dam involve in wide range and long term,which cause certain influence on the ecology and environment through the changes in aquatic ecosystem and hydrological condition.Based on the characters of dam and watershed ecosystem,the latest researches were focused on the ecological effects of dam in regulating hydrological process and local ecological condition,barrier effects and insularity,intercepting effects,edge effects,and water thermal effects.Deriving from the concepts of food chain and web,this paper defined the ecological effect chain and web of dam,on the basis of analyzing the conception and connotation of ecological effect,and firstly,its history,and put forward the research directions on the ecological effects of dam,i.e.,1) what the ecological positive effects and the ecological effect chains and webs are,and how to explore,build and assess them,2) how to identify and underline the ecological effects on the ecosystem process and condition,3) how to address and distinguish the characteristics of each ecological effect at different temporal and spatial scale,make the relationships between them clear,and to scale down and up.These researches would avail our serious consideration to the planning,building,operating and managing of dams.