Trade-off and synergy analysis among ecosystem services in a karst watershed

The underground river watersheds in karst areas are undergoing the degradation of ecosystem functions, thus hindering the development of benefits to humans. Taking the Nandong underground river watershed (NURW) as a test case in southern China, this study evaluated net primary productivity (NPP), water yield (WY), and soil retention (SR) and the relationships between the three factors from 2000 to 2018. The results showed that (1) NPP exhibited a continuously rising trend from 2000 to 2018, and the WY and SR also increased in general; (2) land use was an important influencing factor for ecosystem services, and the synergy between the two improved since 2006; (3) the ecosystem synergy was poor in the NURW, and the conflicts among ecosystem services were especially severe in areas with a high incidence of rocky desertification. This study will provide a reference for regional governments by clarifying the possible future state of the ecosystem.