Integrating ecological and socioeconomic networks using nitrogen metabolism in the Yellow River Delta, China

Abstract

Coastal wetland resources are important factors restricting the sustainable economic development of the Yellow River Delta of China (i.e., Dongying city). The objectives of this study were to develop a method to integrate ecological and socioeconomic networks to make the currently independent research on ecology and social economy more cohesive and measure the sustainable development of wetland resources and economy. In this study, we constructed a nitrogen metabolism network model to connect the two networks using certain nodes as interfaces by material transfer, resource utilization or public environment. We used ecological network analysis to examine nitrogen flows and relationships over two decades, i.e., from 1995 to 2015. A total of 26 nodes connected 135–136 direct and 676 integral paths in the integrated metabolic network. The results showed that Dongying city was in a state of nitrogen accumulation, and nitrogen sequestration increased in the atmosphere and decreased in coastal wetlands. Three key paths of nitrogen flow growth and 12 stable key paths were identified. Key nodes with a higher influence on the specific node were observed based on the integral flow. Stable competition relationships mainly existed within wetland resources, and intricate exploitation relationships existed in the socioeconomic system and between wetland resources and socioeconomic nodes. The findings of this work indicate that nitrogen metabolism is suitable for accurately identifying the key nodes, paths and influences from human activities, and ecological relationships of an integrated network, which can provide a reference for wetland restoration, industrial restructuring and urban sustainability.