Assessing the effectiveness of water retention ecosystem service in qinling national nature reserve based on invest and propensity score matching model

Abstract

Aims: Nature reserves (NRs) play an important role in ensuring ecosystem services such as water retention, which are of great significance for the sustainable use of regional water resources. However, the main factors influencing the —————————————————— effectiveness of water retention in NRs are still unclear, which is not conducive to the effective management of NRs and the achievement of regional sustainable development goals. Therefore, the aims of this research are to explore: (1) the overall situation of water retention services in Qinling Mountains; (2) the conservation effectiveness of water retention services in NRs; and (3) the key influencing factors of the conservation effectiveness of water retention services in NRs. Methods: Here, we used the InVEST model to calculate the water retention between 2010 and 2015 in Qinling Mountains related to 19 national nature reserves. Based on the propensity score matching approach, we assessed the conservation effectiveness of these nature reserves in ensuring the ecosystem service of water retention. We then used the random forest regression model to identify the factors that mainly affect the conservation effectiveness. Results: The results showed that the water retention ecosystem service in Qinling Mountains generally reduced between 2010 and 2015. Compared with the matched samples outside the NRs, most reserves (63.16%) showed significant positive effects on water retention (N = 12, P < 0.05), while some reserves (26.32%) showed significant negative effects (N = 5, P < 0.05). There were also two reserves (10.52%) that had no significant effects on water retention (N = 2, P > 0.05). In addition, the conservation effectiveness of reserves in ensuring water retention was mainly affected by changes in precipitation and funding investment. Conclusions: (1) Between 2010 and 2015, the water retention rate was reduced remarkably in Qinling Mountains, but the NRs had achieved positive effectiveness in mitigating the reduction of water retention in general; (2) Changes in precipitation play a dominant role in sustaining the ecosystem service of water retention; and (3) The management factors also affect the conservation effectiveness to certain extent, in which the amount of investment is the most important. Therefore, we suggest increasing capital investment in the future to improve the conservation effectiveness of water retention service of NRs.