Coupling relationship among ecosystem services and its driving factors from the perspective of social-ecological networks

Abstract

[Objective] Exploring the driving factors and dynamic change characteristics of the coupling relationship between ecosystem service trade-offs and synergies is crucial for clarifying the mutual feedback mechanism of social-ecological systems in the context of ecological restoration. [Methods] In this study, we selected Yan’an City, a typical vegetation restoration area, as the study area, and quantified four ecosystem services including carbon sequestration, water yield, baseflow regulation, and soil conservation from 2000 to 2020. Then we used a comprehensive ecosystem services index (ESI) to characterize the coupling relationship between the four ecosystem services. Based on the Bayesian belief networks (BBNs) model, we developed a network structure, which captured the driving factors of ESI and identified the variation characteristics of ESI. [Results] The results show that: (1) The ESI of Yan’an City increased significantly from 2000 to 2020, with the high value areas of ESI expanded from the middle to the north and south of the city, and the low value areas of ESI concentrated around the town and the northern fringe area. The baseflow regulation steadily declined since 2000. (2) The combined contribution rates of precipitation, fractional vegetation cover (FVC), actual evapotranspiration, and temperature to the change of ESI were more than 70% in 2000 to 2020, in which precipitation and FVC were the dominant driving factors. (3) In the 20-year study period, the contribution rate of precipitation showed a fluctuating downward trend but the contribution rate of FVC kept rising. According to the scenarios of probabilistic inference of BBNs, increasing temperature and precipitation will aggravate the risk of loss for baseflow regulation, while the continuous vegetation restoration will also lead to the threshold effects for the optimization of ESI. [Conclusion] A long-term monitoring of vegetation restoration areas and the improvement of baseflow regulation should be the priorities for Yan’an City in order to maintain the effectiveness of vegetation restoration and to cope with climate change and human disturbances in the future.

Keywords

• ecosystem services|coupling relationship|driving factors|bayesian belief networks|yan’an city