Patterns and controlling factors of soil carbon sequestration in nitrogen-limited and -rich forests in China—a meta-analysis

PeerJ

article

Mbezele Junior Yannick Ngaba¹  Yves Uwiragiye¹  Jianbin Zhou¹ 

[1] College of Natural Resources and Environment, Northwest A&F University;Key Laboratory of Plant Nutrition and the Agri-Environment in Northwest China, Ministry of Agriculture;College of Resources and Environment, Southwest University;University of Technology and Arts of Byumba

关键词: Carbon sequestration;    Belowground soil C processes;    Nitrogen addition;    Nitrogen use efficiency;   

DOI  :  10.7717/peerj.14694

学科分类：社会科学、人文和艺术（综合）

来源: Inra

【 摘 要 】

Soil organic carbon (SOC) management has the potential to contribute to climate change mitigation by reducing atmospheric carbon dioxide (CO2). Understanding the changes in forest nitrogen (N) deposition rates has important implications for C sequestration. We explored the effects of N enrichment on soil carbon sequestration in nitrogen-limited and nitrogen-rich Chinese forests and their controlling factors. Our findings reveal that N inputs enhanced net soil C sequestration by 5.52–18.46 kg C kg−1 N, with greater impacts in temperate forests (8.37–13.68 kg C kg−1 N), the use of NH4NO3 fertilizer (7.78 kg Ckg−1 N) at low N levels (<30 kg Ckg−1 N; 9.14 kg Ckg−1 N), and in a short period (<3 years; 12.95 kg C kg−1 N). The nitrogen use efficiency (NUE) varied between 0.24 and 13.3 (kg C kg−1 N) depending on the forest type and was significantly controlled by rainfall, fertilizer, and carbon-nitrogen ratio rates. Besides, N enrichment increased SOC concentration by an average of 7% and 2% for tropical and subtropical forests, respectively. Although soil carbon sequestration was higher in the topsoil compared to the subsoil, the relative influence indicated that nitrogen availability strongly impacts the SOC, followed by dissolved organic carbon concentration and mean annual precipitation. This study highlights the critical role of soil NUE processes in promoting soil C accumulation in a forest ecosystem.

【 授权许可】

CC BY