Organic matter chemistry and bacterial community structure regulate decomposition processes in post-fire forest soils

Wildfires decrease forest aboveground biomass and have long-term legacy effects on carbon (C) stocks in soil via alterations of microbial communities and functions. However, the interactions between soil organic C (SOC) chemodiversity and bacterial communities that drive C decomposition remain unclear. Soils from two boreal forest sites, 3 months (S1) and 15 years (S2) after fire events, were incubated for 53 days to quantify the mineralization of sucrose (mimicking rhizodeposits, δ13C = −11.97‰) and SOC priming. To reveal SOC-bacterial interactions that regulate SOC decomposition, the isotopic abundance, SOC chemical composition (13C NMR), and associated bacterial community structure (16S rRNA gene sequencing) were analyzed. The best multivariate model (DISTLM) analysis indicated that aromatic C (phenolic-C and aryl-C) in S1 and di-O-alkyl C in S2 were the largest contributors to bacterial community structure. The co-occurrence network confirmed SOC-bacteria interactions, and revealed the highly co-occurrent groups, i.e. Paenibacillus in S1 and Bacillus in S2, both of which belong to the Firmicutes, correlated with recalcitrant C and labile C, respectively, and are potentially linked to decomposition. For example, Firmicutes (as well as Proteobacteria and Actinobacteria) were correlated with aryl-C and phenolic-C in S1 and highly correlated with SOC priming intensity. The limited C resources (enriched refractory components, i.e. phenolic substances) in S1 favored oligotrophs to outcompete other bacterial groups, which likely aided decomposition of more recalcitrant SOC via co-metabolisms. The slow decomposition of sucrose and large soil priming effects observed in S1 suggested a faster SOC turnover via bidirectional processes of additional sucrose-C gain and native soil-C loss. Collectively, changes in SOC chemistry were coupled with an altered bacterial community, and their interactions might further correlate to decomposition, with implications for C sequestration in the post-fire boreal forest soils. © 2021 Elsevier Ltd

Ling L.1 , Fu Y.1 , Jeewani P.H.1, 2 , Tang C.3 , Pan S.1 , Reid B.J.4 , Gunina A.5 , Li Y. 1, 6 , Li Y. 1, 6 , Cai Y.6 , Kuzyakov Y. 7, 8 , Li Y. 1, 6 , Su W.-Q.1 , Singh B.P.9 , Luo Y.1 , Xu J.1
Elsevier Ltd
  • 1 Institute of Soil and Water Resources and Environmental Science, College of Environmental and Resource Sciences, Zhejiang Provincial Key Laboratory of Agricultural Resources and Environment, Zhejiang University, Hangzhou, 310058, China
  • 2 Department of Agriculture, Southern Province, Labuduwa, Galle, 80000, Sri Lanka
  • 3 Department of Animal, Plant and Soil Sciences, Centre for AgriBioscience, La Trobe University, Melbourne Campus, Bundoora, VIC 3086, Australia
  • 4 School of Environmental Sciences, University of East Anglia, Norwich, UK NR4 7TJ, United Kingdom
  • 5 Department of Environmental Chemistry, University of Kassel, Germany
  • 6 State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Hangzhou, 311300, China
  • 7 Department of Soil Science of Temperate Ecosystems, Department of Agricultural Soil Science, University of Gottingen, Gottingen, 37077, Germany
  • 8 Agro-Technological Institute, RUDN University, Moscow, 117198, Russian Federation
  • 9 NSW Department of Primary Industries, Elizabeth Macarthur Agricultural Institute, Menangle, NSW 2568, Australia
Ключевые слова
C sequestration; C-microorganisms interactions; Core microorganisms; Forest fire; Priming effect
Дата создания
Дата изменения
Постоянная ссылка

Другие записи