Sulfur biogeochemical dynamics of grassland soils in northern China transect along an aridity gradient
Yi-Wen Cao,
Xiao-Bo Wang,
Chao Wang,
Edith Bai,
Nanping Wu
Affiliations
Yi-Wen Cao
CAS Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China; Guangdong Provincial Key Laboratory of Soil and Groundwater Pollution Control, School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
Xiao-Bo Wang
CAS Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China; State Key Laboratory of Herbage Improvement and Grassland Agro-ecosystems, Center for Grassland Microbiome, and College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou, China
Chao Wang
CAS Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China
Edith Bai
CAS Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China; Key Laboratory of Geographical Processes and Ecological Security of Changbai Mountains, Ministry of Education, School of Geographical Sciences, Northeast Normal University, Changchun, China
Nanping Wu
Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences, Sanya 572000, China; School of Earth, Atmosphere & Environment, Monash University, Victoria 3800, Australia; Corresponding author at: Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences, Sanya 572000, China.
As an essential nutrient element for biological growth and metabolism, sulfur is closely interlinked with the carbon and nitrogen cycles, and it is one of the limiting elements for grassland productivity. Here we investigated the spatial distribution of sulfur contents and 34S stable isotope along the North China Transect (NCT), with the aim to explore the shaping role of the aridity index (AI) gradient on sulfur cycling dynamic in arid and semi-arid grasslands. In the area with AI < 0.12, soil sulfur contents and sulfur isotopic compositions (δ34S) showed no correlation with AI, indicating that abiotic processes predominantly govern the sulfur cycle in this area. In the area where 0.12 ≤ AI < 0.32, both sulfur contents and δ34S values increased with rising AI, with microbial-mediated reduction being the primary sulfur cycling process. In the area with 0.32 ≤ AI < 0.60, soil sulfur contents continued to increase with higher AI, but δ34S significantly decreased as AI increased, suggesting plant uptake as the dominant sulfur cycling process in this area. This study demonstrated the significant impact of AI on sulfur dynamics, providing insights into the different drivers of sulfur cycling along the aridity gradient, and offering guidance for developing targeted strategies under global climate change.
