Soil moisture decline in China's monsoon loess critical zone: More a result of land- use conversion than climate change

• 成果类型: Article
• 署名作者: Wang, Yunqiang; Hu, Wei; Sun, Hui; Zhao, Yali; Zhang, Pingping; Li, Zimin; Zhou, Zixuan; Tong, Yongping; Liu, Shaozhen; Zhou, Jingxiong; Huang, Mingbin; Jia, Xiaoxu; Clothier, Brent; Shao, Ming'an; Zhou, Weijian; An, Zhisheng
• 署名单位: Chinese Academy of Sciences; Institute of Earth Environment, CAS; Xi'an Jiaotong University; New Zealand Institute for Plant & Food Research Ltd; Chinese Academy of Sciences; University of Chinese Academy of Sciences, CAS; Chinese Academy of Sciences; Institute of Soil & Water Conservation (ISWC), CAS; Ministry of Water Resources; Chinese Academy of Sciences; Institute of Geographic Sciences & Natural Resources Research, CAS; New Zealand Institute for Plant & Food Research Ltd; Beijing Normal University
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-9128
• DOI: 10.1073/pnas.2322127121
• 发表日期: 2024-04-09
• 关键词: yellow-river

摘要

Soil moisture (SM) is essential for sustaining services from Earth's critical zone, a thinliving skin spanning from the canopy to groundwater. In the Anthropocene epoch, intensive afforestation has remarkably contributed to global greening and certain service improvements, often at the cost of reduced SM. However, attributing the response of SM in deep soil to such human activities is a great challenge because of the scarcity of long - term observations. Here, we present a 37 y (1985 to 2021) analysis of SM dynamics at two scales across China's monsoon loess critical zone. Site - scale data indicate that land - use conversion from arable cropland to forest/grassland caused an 18% increase in SM deficit over 0 to 18 m depth (P < 0.01). Importantly, this SM deficit intensified over time, despite limited climate change influence. Across the Loess Plateau, SM storage in 0 to 10 m layer exhibited a significant decreasing trend from 1985 to 2021, with a turning point in 1999 when starting afforestation. Compared with SM storage before 1999, the relative contributions of climate change and afforestation to SM decline after 1999 were -8% and 108%, respectively. This emphasizes the pronounced impacts of intensifying land - use conversions as the principal catalyst of SM decline. Such a decline shifts 18% of total area into an at - risk status, mainly in the semiarid region, thereby threatening SM security. To mitigate this risk, future land management policies should acknowledge the crucial role of intensifying land - use conversions and their interplay with climate change. This is imperative to ensure SM security and sustain critical zone services.