Effects of nitrogen addition on microbial residues and their contribution to soil organic carbon in China's forests from tropical to boreal zone

Suhui Ma; Guoping Chen; Enzai Du; Di Tian; Aijun Xing; Haihua Shen; Chengjun Ji; Chengyang Zheng; Jianxiao Zhu; Jiangling Zhu; Hanyue Huang; Hongbo He; Biao Zhu; Jingyun Fang

doi:10.1016/j.envpol.2020.115941

Effects of nitrogen addition on microbial residues and their contribution to soil organic carbon in China's forests from tropical to boreal zone

Environ Pollut. 2021 Jan 1;268(Pt B):115941. doi: 10.1016/j.envpol.2020.115941. Epub 2020 Oct 28.

Authors

Suhui Ma¹, Guoping Chen¹, Enzai Du², Di Tian³, Aijun Xing⁴, Haihua Shen⁴, Chengjun Ji¹, Chengyang Zheng¹, Jianxiao Zhu⁵, Jiangling Zhu¹, Hanyue Huang¹, Hongbo He⁶, Biao Zhu¹, Jingyun Fang⁷

Affiliations

¹ Institute of Ecology, College of Urban and Environmental Sciences, And Key Laboratory for Earth Surface Processes of the Ministry of Education, Peking University, Beijing, 100871, China.
² State Key Laboratory of Earth Surface Processes and Resource Ecology, School of Natural Resources, Faculty of Geographical Science, Beijing Normal University, Beijing, 100875, China.
³ College of Life Sciences, Capital Normal University, Beijing, 100048, China.
⁴ State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China.
⁵ College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou, 730000, China.
⁶ Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, 110016, China.
⁷ Institute of Ecology, College of Urban and Environmental Sciences, And Key Laboratory for Earth Surface Processes of the Ministry of Education, Peking University, Beijing, 100871, China. Electronic address: jyfang@urban.pku.edu.cn.

PMID: 33162211
DOI: 10.1016/j.envpol.2020.115941

Abstract

Atmospheric nitrogen (N) deposition has a significant influence on soil organic carbon (SOC) accumulation in forest ecosystems. Microbial residues, as by-products of microbial anabolism, account for a significant fraction of soil C pools. However, how N deposition affects the accumulation of soil microbial residues in different forest biomes remains unclear. Here, we investigated the effects of six/seven-year N additions on microbial residues (amino sugar biomarkers) in eight forests from tropical to boreal zone in eastern China. Our results showed a minor change in the soil microbial residue concentrations but a significant change in the contribution of microbial residue-C to SOC after N addition. The contribution of fungal residue-C to SOC decreased under low N addition (50 kg N ha^-1 yr^-1) in the tropical secondary forest (-19%), but increased under high N addition (100 kg N ha^-1 yr^-1) in the temperate Korean pine mixed forest (+21%). The contribution of bacterial residue-C to SOC increased under the high N addition in the subtropical Castanopsis carlesii forest (+26%) and under the low N addition in the temperate birch forest (+38%), respectively. The responses of microbial residue-C in SOC to N addition depended on the changes in soil total N concentration and fungi to bacteria ratio under N addition and climate. Taken together, these findings provide the experimental evidence that N addition diversely regulates the formation and composition of microbial-derived C in SOC in forest ecosystems.

Keywords: Amino sugars; Fertilization; Microbial biomass; Microbial necromass; Nitrogen deposition; Soil nitrogen.

MeSH terms

Carbon* / analysis
China
Ecosystem
Forests
Nitrogen / analysis
Soil Microbiology
Soil*

Substances

Soil
Carbon
Nitrogen