How are nature-based solutions contributing to the improvement of ecosystem quality in China: A systematic review

Nature-based solutions (NbS), an upgraded version of ecological restoration concept, has developed as an integrated approach to encompass a broad range of actions that protect, restore, or sustainably manage ecosystems to provide benefits to people. However, it is challenging to obtain a thorough understanding of the effectiveness of NbS because of the uncertainty of the assessment in different regions based on ecosystem services. Here, we conduct a synthesis analysis of the effects of ecological interventions on ecosystem quality within China. We systematically analyze 76 studies selected from 275 peer-reviewed papers, which were undertaken at regional scale and published between 2011 and 2022. Average values of ecosystem services before and after the ecological interventions are extracted to quantify the ecosystem changes. Results show that ecological restoration purposefully contributes to the improvements of ecosystem services with an increase in Net Primary Productivity (NPP) of 31% and an increase in soil conservation (SC) of 21%. Effects on water yield (WY), carbon storage (CS) and habitat quality (HQ) are all not significant. Restoration interventions have a mixed effect on ecosystem service trade-offs which may vary by regions. Trade-offs primarily exist between WY and other ecosystem services on the Northeastern Forest Belt and the Southwestern Karst, while synergies mainly exist among NPP, SC and CS on the Loess Plateau and the Qinghai-Tibet Plateau. Moreover, utilizing grey correlation analysis methods, factor analysis reveals that temperature and precipitation are highly correlated with the changes of the five ecosystem services. Natural factors contribute more to the changes of NPP, SC and WY than the human factors. This research is aimed at obtaining an overall perception of the effectiveness of ecological restoration programmes implementation in different regions across China, which will provide references for reducing ecosystem services trade-offs and adjusting the layouts of regional ecological restoration programmes.