Spatial variations and mechanisms for the stability of water use efficiency in China

Xiaojuan Xu; Jing Liu; Fusheng Jiao; Kun Zhang; Yue Yang; Jie Qiu; Yingying Zhu; Naifeng Lin; Changxin Zou

doi:10.3389/fpls.2023.1254395

Spatial variations and mechanisms for the stability of water use efficiency in China

Front Plant Sci. 2023 Sep 21:14:1254395. doi: 10.3389/fpls.2023.1254395. eCollection 2023.

Authors

Xiaojuan Xu¹, Jing Liu¹, Fusheng Jiao², Kun Zhang¹, Yue Yang¹, Jie Qiu¹, Yingying Zhu¹, Naifeng Lin¹, Changxin Zou¹

Affiliations

¹ Nanjing Institute of Environmental Sciences, MEE, Nanjing, China.
² School of Geography, Nanjing Normal University, Nanjing, China.

Abstract

A clearer understanding of the stability of water use efficiency (WUE) and its driving factors contributes to improving water use efficiency and strengthening water resource management. However, the stability of WUE is unclear. Based on the EEMD method, this study analyses the spatial variations and mechanisms for the stability of WUE in China, especially in the National Forest Protection Project (NFPP) areas. It is found that the stable WUE was dominated by non-significant trends and increasing trends in China, accounting for 33.59% and 34.19%, respectively. The non-significant trend of stable WUE was mainly located in the Three-North shelterbelt program area, and the increasing trend of stable WUE was in Huaihe and Taihu, Taihang Mountains, and Pearl River shelterbelt program areas. Precipitation and soil moisture promoted the stable WUE in these project areas. The unstable WUE was dominated by positive reversals or negative reversals of WUE trends. The positive reversals of unstable WUE were mainly located in the Yellow River shelterbelt program areas, which was promoted by temperature and radiation, while the negative reversals of unstable WUE were mainly distributed in the Yangtze River and Liaohe shelterbelt program areas, which were mainly induced by saturation water vapor pressure difference (VPD). Our results highlight that some ecological restoration programs need to be improved to cope with the negative climate impact on the stability of WUE.

Keywords: climate change; driving factors; ecological restoration; stability; water use efficiency.

Grants and funding

This study was supported by the National Key R&D Program of China (2021YFB3901104). The Special Fund of the Jiangsu for Carbon Peak and Carbon Neutralization Science and Technology Innovation (BK20220021), and the Special Fund of the Chinese Central Government for Basic Scientific Research Operations in the commonweal Research Institute (GYZX210405).