Soil microbial populations in deep floodplain soils are adapted to infrequent but regular carbon substrate addition
dc.contributor.author | Cressey, EL | |
dc.contributor.author | Dungait, JAJ | |
dc.contributor.author | Jones, DL | |
dc.contributor.author | Nicholas, AP | |
dc.contributor.author | Quine, TA | |
dc.date.accessioned | 2018-05-15T09:36:55Z | |
dc.date.issued | 2018-04-12 | |
dc.description.abstract | Floodplain soils provide an important link in the land-ocean aquatic continuum. Understanding microbial activity in these soils, which can be many metres deep, is a key component in our understanding of the role of floodplains in the carbon (C) cycle. We sampled the mineral soil profile to 3 m depth from two floodplain sites under long-term pasture adjacent to the river Culm in SW England, UK. Soil chemistry (C, nitrogen (N), phosphorus (P), soil microbial biomass (SMB), moisture content) and soil solution (pH, dissolved organic C (DOC) and N, nitrate, ammonium, water extractable P) were analysed over the 3 m depth in 6 increments: 0.0–0.2, 0.2–0.7, 1.0–1.5, 1.5–2.0, 2.0–2.5, and 2.5–3.0 m. 14 C-glucose was added to the soil and the evolution of 14 CO 2 measured during a 29 d incubation. From soil properties and 14 C-glucose mineralisation, three depth groups emerged, with distinct turnover times extrapolated from initial k 1 mineralisation rate constants of 2 h (topsoil 0.0–0.2 m), 4 h (subsoil 0.2–0.7 m), and 11 h (deep subsoil 1.0–3.0 m). However, when normalised by SMB, k 1 rate constants had no significant differences across all depths. Deep subsoil had a 2 h lag to reach maximal 14 CO 2 production whereas the topsoil and subsoil (0.2–0.7 m) achieved maximum mineralisation rates immediately. SMB decreased with depth, but only to half of the surface population, with the proportion of SMB-C to total C increasing from 1% in topsoil to 15% in deep subsoil ( > 1.0 m). The relatively large SMB concentration and rapid mineralisation of 14 C-glucose suggests that DOC turnover in deep soil horizons in floodplains is limited by access to biologically available C and not the size of the microbial population. | en_GB |
dc.description.sponsorship | Natural Environment Research Council (NERC) | en_GB |
dc.description.sponsorship | Biotechnology and Biological Sciences Research Council (BBSRC) | en_GB |
dc.identifier.citation | Vol. 122, pp. 60 - 70 | en_GB |
dc.identifier.doi | 10.1016/j.soilbio.2018.04.001 | |
dc.identifier.grantnumber | NE/E011713/1 | en_GB |
dc.identifier.grantnumber | BB/P01268X/1 | en_GB |
dc.identifier.uri | http://hdl.handle.net/10871/32862 | |
dc.language.iso | en | en_GB |
dc.publisher | Elsevier | en_GB |
dc.relation.source | Data supporting this study are stored by the corresponding author at the University of Exeter. | en_GB |
dc.rights | Crown Copyright © 2018 This is an open access article under the CC BY licence. | en_GB |
dc.subject | Soil organic carbon | en_GB |
dc.subject | Soil microbial biomass | en_GB |
dc.subject | 14C-labelling | en_GB |
dc.subject | Dissolved organic carbon | en_GB |
dc.subject | Depth | en_GB |
dc.subject | Mineralisation | en_GB |
dc.subject | Floodplain | en_GB |
dc.subject | Stoichiometry | en_GB |
dc.title | Soil microbial populations in deep floodplain soils are adapted to infrequent but regular carbon substrate addition | en_GB |
dc.type | Article | en_GB |
dc.date.available | 2018-05-15T09:36:55Z | |
dc.identifier.issn | 0038-0717 | |
dc.description | This is the final version of the article. Available from Elsevier via the DOI in this record. | en_GB |
dc.identifier.journal | Soil Biology and Biochemistry | en_GB |
dc.rights.uri | https://creativecommons.org/licenses/by/4.0/ |
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This is an open access article under the CC BY licence.