Impact of vegetation restoration on ecosystem services in the Loess plateau, a case study in the Jinghe Watershed, China

Abstract

Assessing ecosystem services (ESs) is vital for the environment development. This study explored the variation characteristics of ESs under the restoring vegetation since the Grain for Green Project (GFGP) in Jinghe Watershed, which is a typical watershed experiencing severe soil erosion in the Loess Plateau of China. Herein, the fractional vegetation cover (FVC) is selected as an indicator of the changes in vegetation restoration from 2000 to 2020. Simulations of ESs are based on the Soil and Water Assessment Tool (SWAT), Carnegie Ames-Stanford Approach (CASA) model, Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST). This paper analyzed the spatiotemporal heterogeneity in vegetation coverage and the response of vegetation coverage to ESs in the Jinghe Watershed with Mann-Kendall test, Pearson correlation coeffificient R and the gray relational analysis (GRA). The results showed that: (1) Since the implementation of the GFGP, the area of forests and grassland has increased significantly. The proportion of vegetation restoration area was 95.15 %; (2) At the whole watershed scale, vegetation restoration and soil conservation (SC), water yied (WY), net primary production (NPP) and habitat quality (HQ) were synergistic relationships, while focusing on the sub-watershed scale, vegetation restoration and SC and HQ were transformed into trade-off relationships in some sub-watershed. (3) Vegetation restoration in the Jinghe Watershed had positive effects on SC, WY, NPP, and HQ. The order of relevance with vegetation restoration was: SC > HQ > NPP > WY, indicating that vegetation restoration in the Jinghe Watershed has the highest closeness to SC. This study showed that since the implementation of the GFGP, vegetation coverage in the Jinghe Watershed has significantly restored, which has promoted the improvement of ESs.