An approach to assess spatio-temporal heterogeneity of rural ecosystem health: A case study in Chongqing mountainous area, China

Abstract

Rural ecosystem health is an effective metrics of the stable state of rural components and subsystems referring to the ability to meet the reasonable needs of human society, self-maintain and update the ecosystem. With the development of regional ecosystem assessment, the theoretical breakthrough demand to integrate ecosystem composition integrity and ecosystem services (ES) supply–demand from the perspective of coupled human and ecosystem into ecosystem health assessment is increasing, stakeholders are interested in improving some comprehensive evaluation framework to reverse inadequate understanding of focusing on the single measurement of rural natural ecosystem status and external disturbance. This study established an improved rural ecosystem health assessment framework (REH-SD) with integrating ecological integrity and ES supply–demand from the perspective of social-economy-natural complex ecosystem, which put forward a set of assessment index system combining with SDGs17 indicators, and took Chongqing as a case study to reveal quantitatively spatiotemporal heterogeneity characteristics of rural ecosystem health. The results shown that: 1) The comprehensive score of rural ecosystem health in Chongqing from 2008 to 2018 was formed into an obvious variation evolutionary rule of gentle wave first and then rising rapidly ranging from 0.618 to 0.885, which was consistent with the trend of the physical state of rural ecosystem health (PREH); 2) The rural ecosystem health of 36 districts and counties in Chongqing increased gradually from the west Chongqing and metropolitan areas to the northeast and southeast Chongqing on the whole, showing a spatial heterogeneity of central and western collapse, northeast wings high, local protrusion, and the unhealth type (33.33%) and subhealth type (27.78%) dominated throughout the study area in 2018; 3) The improved REH-SD framework could appropriately modify the traditional evaluation results according to supply and demand relationship, the serious ecological deficit in metropolitan areas aggravated dramatically the deterioration of rural ecosystem, inversely, the REH-SD was significantly affected by the PREH in northeast and southeast Chongqing. The improved REH-SD framework was verified to be advanced comparing with the traditional evaluation method, and our results could provide significant differentiated recommendations for mountain ecological environment protection and restoration project.