Impacts of vegetation restoration on water resources and carbon sequestration in the mountainous area of Haihe River basin, China

Teng Ma; Taihua Wang; Dawen Yang; Shuyu Yang

doi:10.1016/j.scitotenv.2023.161724

Impacts of vegetation restoration on water resources and carbon sequestration in the mountainous area of Haihe River basin, China

Sci Total Environ. 2023 Apr 15:869:161724. doi: 10.1016/j.scitotenv.2023.161724. Epub 2023 Jan 25.

Authors

Teng Ma¹, Taihua Wang¹, Dawen Yang², Shuyu Yang¹

Affiliations

¹ State Key Laboratory of Hydroscience and Engineering, Department of Hydraulic Engineering, Tsinghua University, Beijing 100084, China.
² State Key Laboratory of Hydroscience and Engineering, Department of Hydraulic Engineering, Tsinghua University, Beijing 100084, China. Electronic address: yangdw@tsinghua.edu.cn.

PMID: 36708819
DOI: 10.1016/j.scitotenv.2023.161724

Abstract

The mountainous region of the Haihe River basin (MHRB) plays an important role in the water resource supply of its nearby mega-cities, including Beijing and Tianjin, and large areas of cropland. With the implementation of afforestation projects in recent decades, vegetation and carbon (C) uptake have greatly increased in the MHRB. In addition, the annual runoff has significantly declined, threatening regional water security. The trade-off relationship between water yield and C uptake in the MHRB remains unknown. This study employed a biogeochemical model (Biome-BGC) to simulate the natural vegetation dynamics and gross primary productivity (GPP) during 1982-2019 driven by climate forcing. A distributed hydrological model (geomorphology-based hydrological model, GBHM) was adopted to assess the impact of vegetation restoration on the hydrological processes. The results indicated that the leaf area index in the MHRB increased significantly (P < 0.01) during 1982-2019, which led to evapotranspiration increase and runoff (R) reduction. Under the influence of vegetation restoration, both the GPP and the water use efficiency (WUE) increased significantly in the MHRB during 2000-2019, however, the improvement of WUE decreased with the aridity index increasing. Our results showed that vegetation restoration can improve C sequestration efficiency in the MHRB and that the trade-off between water yield and C sequestration should be considered in planning ecological projects to achieve C neutrality.

Keywords: Evapotranspiration; Gross primary production; Vegetation restoration; Water use efficiency; Water yield.