水生态系统概念的演进、内涵与展望OA

Under the intensifying impacts of global climate change and increasing human activities,water scarcity,water pollution,water ecological degradation,and water-related hazards are becoming more frequent and severe.Water security problems are increasingly characterized by cross-scale interactions,multi-process coupling,and non-linear dynamics,reflecting the complexity of integrated human-water-ecosystem systems.However,conventional research paradigms on water ecosystems,which predominantly focus on single ecosystems or aquatic biota,have inherent limitations in terms of object definition,process representation,and spatial scale,being difficult to systematically reveal the overall evolution mechanisms of water ecosystems under the complex coupling of human-water-ecological dynamics.This study systematically reviewed the conceptual evolution of water ecosystems,categorizing their development into three stages:biology being dominated,introduction and deepening of systems thinking,and multi-element coupling with spatial-scale expansion.The theoretical characteristics and limitations of each stage are summarized.Overall,water ecosystem research has progressed from descriptions of aquatic biological communities to analysis of ecosystem processes and further toward integrated studies of multiple elements,processes,and spatial scales.On this basis,a macro-ecosystem perspective is introduced to redefine the water ecosystem,and it is conceptualized as a dynamic whole with specific structures,functions,and ecosystem service values,formed through the interactions and interdependence between biological communities and the abiotic environment via energy flows and material cycles across the entire water cycle space.This framework extends the research boundary beyond individual water bodies and incorporates atmospheric water,surface water,soil water,groundwater,snow and ice,and artificial water systems,together with key hydrological processes such as precipitation,interception,evapotranspiration,infiltration,runoff,and groundwater recharge.It treats human activities,including water withdrawal,water use,water transfer,storage,drainage,engineering regulation,and land-use change,as integral components of the system rather than merely external disturbances.This definition emphasizes the integrity of the whole water cycle,the integrity of watershed/regional scales,and the deep coupling of natural,social,and economic systems.Furthermore,the scientific significance and application prospects of the water ecosystem concept under a macro-ecosystem framework are discussed from the perspectives of eco-hydrological coupling mechanisms,watershed water resources management and ecological restoration,regional water security and environmental protection,adaptation to climate change,and integrated governance of mountains,waters,forests,fields,lakes,grasslands,and deserts.In addition,the proposed framework highlights the need to strengthen cross-scale observation,multi-process coupling analysis,and integrated monitoring and modeling,thereby improving the understanding of water ecosystem dynamics,resilience,and risk transmission under global environmental change.