Competitive interaction with keystone taxa induced negative priming under biochar amendments

Microbiome

Qinsong Xu¹  Cheng Han²  Yu Luo³  Chao Liang⁴  Yuji Jiang⁵  Qiguo Zhao⁵  Bo Sun⁵  Lijun Chen⁶ 

[1] 0000 0001 0089 5711, grid.260474.3, College of Life Science, Nanjing Normal University, 210023, Nanjing, China;0000 0001 0089 5711, grid.260474.3, School of Geography Science, Nanjing Normal University, 210023, Nanjing, China;0000 0004 1759 700X, grid.13402.34, Zhejiang Provincial Key Laboratory of Agricultural Resources and Environment, Institute of Soil and Water Resources and Environmental Science, Zhejiang University, 310058, Hangzhou, China;0000000119573309, grid.9227.e, Institute of Applied Ecology, Chinese Academy of Sciences, 110016, Shenyang, China;0000000119573309, grid.9227.e, State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, No. 71 East Beijing Road, 210008, Nanjing, China;0000000119573309, grid.9227.e, State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, No. 71 East Beijing Road, 210008, Nanjing, China;0000 0004 1797 8419, grid.410726.6, University of Chinese Academy of Sciences, 100049, Beijing, China;

关键词: Biochar;    Bacterial and fungal diversity;    Competitive interaction;    DNA-SIP microcosms;    Keystone taxa;    Soil organic carbon mineralization;   

DOI  :  10.1186/s40168-019-0693-7

来源: publisher

【 摘 要 】

BackgroundBiochar amendments have been widely proposed as a conventional and efficient strategy to promote soil organic carbon (SOC) sequestration via negative priming. Unfortunately, the extent and biological mechanisms responsible for biochar-induced negative priming are still not fully understood. Despite traditional explanations focused on the environmental filtering mechanisms of biochar amendments on microbial biomass and community composition underlying the priming effect on SOC dynamics, whether and how a biochar-induced competitive interaction with keystone taxa determines SOC mineralization in natural ecosystems has been minimally explored.ResultsHere, we paid particular attention to the relationships between the diversity and network structure of soil bacterial and fungal communities and SOC mineralization. A 3-year field experiment was conducted comprising five treatments: no fertilization, conventional fertilization, and conventional fertilization with three rates of biochar amendments. Biochar amendments considerably increased soil moisture capacity and pH and subsequently shaped the composition and co-occurrence networks of soil bacterial and fungal communities. Importantly, network analysis revealed that the biochar amendments triggered the competitive interaction with putative keystone taxa in the bacterial and fungal networks. Structural equation modeling suggested that the competitive interaction with keystone taxa promoted bacterial and fungal diversity and consequently reduced carbohydrate catabolism and soil metabolic quotient. Stable isotope probing incubations further provided consistent evidence of competition by keystone taxa with the increases in bacterial and fungal diversity under the biochar amendments.ConclusionsWe found that biochar-induced competition with keystone taxa stimulated the bacterial and fungal diversity and consequently decreased SOC mineralization. The comprehensive understanding of the unexplored biological mechanisms underlying the biochar-induced negative priming may provide crucial implications for enabling SOC sequestration.

【 授权许可】

CC BY