Increased microbial sequestration of soil organic carbon under nitrogen deposition over China’s terrestrial ecosystems

Ecological Processes

Yan Peng¹  Siyi Tan²  Dingyi Wang²  Yusheng Yang²  Xiangyin Ni²  Fuzhong Wu²  Shu Liao²  Kai Yue³ 

[1] Department of Geosciences and Natural Resource Management, University of Copenhagen, Rolighedsvej 23, DK-1958, Frederiksberg C, Denmark;Key Laboratory for Humid Subtropical Eco-Geographical Processes of the Ministry of Education, School of Geographical Sciences, Fujian Normal University, 8 Shangshan Rd, 350007, Fuzhou, Cangshan, China;Key Laboratory for Humid Subtropical Eco-Geographical Processes of the Ministry of Education, School of Geographical Sciences, Fujian Normal University, 8 Shangshan Rd, 350007, Fuzhou, Cangshan, China;Center for Biodiversity Dynamics in a Changing Word (BIOCHANGE), Section for Ecoinformatics and Biodiversity, Department of Biology, Aarhus University, Ny Munkegade 114, DK-8000, Aarhus C, Denmark;

关键词: Microbial necromass carbon;    Nitrogen deposition;    Amino sugars;    Soil organic carbon;   

DOI  :  10.1186/s13717-020-00260-7

来源: Springer

【 摘 要 】

BackgroundChina’s terrestrial ecosystems have been receiving increasing amounts of reactive nitrogen (N) over recent decades. External N inputs profoundly change microbially mediated soil carbon (C) dynamics, but how elevated N affects the soil organic C that is derived from microbial residues is not fully understood. Here, we evaluated the changes in soil microbial necromass C under N addition at 11 forest, grassland, and cropland sites over China’s terrestrial ecosystems through a meta-analysis based on available data from published articles.ResultsMicrobial necromass C accounted for an average of 49.5% of the total soil organic C across the studied sites, with higher values observed in croplands (53.0%) and lower values in forests (38.6%). Microbial necromass C was significantly increased by 9.5% after N addition, regardless of N forms, with greater stimulation observed for fungal (+ 11.2%) than bacterial (+ 4.5%) necromass C. This increase in microbial necromass C under elevated N was greater under longer experimental periods but showed little variation among different N application rates. The stimulation of soil microbial necromass C under elevated N was proportional to the change in soil organic C.ConclusionsThe stimulation of microbial residues after biomass turnover is an important pathway for the observed increase in soil organic C under N deposition across China’s terrestrial ecosystems.

【 授权许可】

CC BY