Examination of wetlands system using ecological network analysis: A case study of Baiyangdian Basin, China

摘要

Understanding the integrality and organization of wetlands system (WS) is important for system-level water resources management and ecological protection. Yet too little research delved into to the whole status assessment of these connected aquatic systems. In this paper, ecological network analysis (ENA) is introduced as a powerful methodology to develop insights into the integrality of Baiyangdian WS. A 23-components steady-state WS model is built on basin macrohydrology in 1962. We investigate how 18 ENA indicators that characterize ecosystem growth, development, and condition are affected by 8 scenarios including (1) increased boundary input, (2) decreased boundary input, (3) increased boundary output, (4) decreased boundary output, (5) addition of new pathway, (6) removal of component, (7) addition of new component and (8) addition of both new pathway and new component. Furthermore, we use coefficient of variation (CV) to compare system indicators' robustness to network changes. Scenario analyses demonstrate that following results regarding current network indicators: I. System indicators will response differently to different scenarios in different extent; II. Whole-indicators, such as Ascendency (A), are generally sensitive to network flow and topology changes; III. Ratio-based indicators and average mutual information (AMI) are basically with lower variability than non-ratio indicator. IV. Most of indictors present high sensitive to network topology changes even if there are few changes in total system throughput (TST). We hypothesize that WS are self-organized into a selective structure that exhibit certain criterion under favorable natural condition. This paper can promote the understanding of integrality of wetlands system and can be served as evidence supporting the need for wetlands policies that go beyond conservation of individual wetland sites.