Process analysis and mitigation strategies for wetland degradation caused by increasing agricultural water demand: an ecology–economy nexus perspective

Abstract

BackgroundFarmland expansion has played a major role in wetland degradation in Heilongjiang Province, China in recent decades. Farmland expansion increases the demands for water, thereby affecting wetland water cycles, and promoting the shrinkage of wetland areas and degradation of ecosystem functions. As an open system, agricultural production is limited by both ecological and socioeconomic conditions. However, our understanding of wetland degradation caused by farmland expansion from the perspective of the ecology–economy nexus is limited.MethodsA correlation between farmland expansion and agricultural economic activities was established, and wetland degradation driven by agroeconomic activities was inversely derived using a multi-regional input–output (MRIO) analysis. We developed an ecology–economy nexus framework to explore the ecological process of the area and water demand tradeoffs between wetland degradation and farmland expansion, the economic process of wetland degradation driven by food consumption, and the nexus between the two processes. We finally explored strategies to mitigate wetland degradation due to increased agricultural water demand.ResultsFarmland expansion contributed to 93.76% of the total degraded wetland area. There was a significant negative correlation between wetland area and the water consumption for crop production, but no significant correlation between wetland area and the ecological footprint of croplands. The direct wetland degradation caused by local final demand accounted for 63.02%, while the indirect degradation caused by non-local final demand accounted for 36.98%. Hebei, Shandong, Liaoning, Inner Mongolia, and Shanghai were the top five provinces contributing to indirect wetland degradation in Heilongjiang. Our findings indicated that a mixed scenario combining water footprint reduction per unit yield with food export reduction could maximize wetland restoration while reducing local farmland–wetland competition for water.ConclusionsOur research highlights the effects of economic processes in the agricultural sector on wetland degradation, and showed that the adjustment of food trade patterns can effectively promote wetland restoration.