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Levasseur PA, Aherne J, Basiliko N, Emilson EJS, Preston MD, Sager EPS, Watmough SA. Soil carbon pools and fluxes following the regreening of a mining and smelting degraded landscape. Sci Total Environ 2023; 904:166734. [PMID: 37673266 DOI: 10.1016/j.scitotenv.2023.166734] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Revised: 08/29/2023] [Accepted: 08/29/2023] [Indexed: 09/08/2023]
Abstract
Increasing forest cover by regreening mining and smelting degraded landscapes provides an opportunity for global carbon (C) sequestration, however, the reported effects of regreening on soil C processes are mixed. One of the world's largest regreening programs is in the City of Greater Sudbury, Canada and has been ongoing since 1978. Prior to regreening, soils in the City of Greater Sudbury area were highly eroded, acidic, rich in metals, and poor in nutrients. This study used a chronosequence approach to investigate how forest soil C pools and fluxes have changed with stand age in highly "eroded" sites with minimal soil cover (n = 6) and "stable" sites covered by soil (n = 6). Encouragingly, the relationship between stand age and soil C processes (litterfall, litter decomposition, soil respiration, fine root growth) at both stable and eroded sites were comparable to observations reported for jack pine (Pinus banksiana Lamb.) and red pine (Pinus resinosa Ait.) plantations that have not been subject to over a century of industrial impacts. There was a strong "home-field advantage" for local decomposers, where litter decomposition rates were higher using a site-specific pine litter compared with a common pine litter. Higher soil respiration at eroded sites was linked to higher soil temperature, likely because of a more open tree canopy. Forest floor C pools increased with stand age while mineral soil C and aggregate C concentrations decreased with stand age. This loss of soil C is small relative to the substantial increases in aboveground tree and forest floor C pools, leading to a sizeable increase in total ecosystem C pools following regreening.
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Affiliation(s)
- Patrick A Levasseur
- Environmental and Life Sciences Graduate Program, Trent University, 1600 West Bank Dr., Peterborough, ON K9J 7B8, Canada.
| | - Julian Aherne
- Trent School of the Environment, Trent University, 1600 West Bank Dr., Peterborough, ON K9J 7B8, Canada
| | - Nathan Basiliko
- Faculty of Natural Resources Management, Lakehead University, 955 Oliver Rd., Thunder Bay, ON P7B 5E1, Canada
| | - Erik J S Emilson
- Natural Resources Canada, Canadian Forest Service, Great Lakes Forestry Centre, 1219 Queen St. East, Sault Ste. Marie, ON P6A 2E5, Canada
| | - Michael D Preston
- Faculty of Environment, University of Northern British Columbia, 3333 University Way, Prince George, BC V2N 4Z9, Canada
| | - Eric P S Sager
- Trent School of the Environment, Trent University, 1600 West Bank Dr., Peterborough, ON K9J 7B8, Canada
| | - Shaun A Watmough
- Trent School of the Environment, Trent University, 1600 West Bank Dr., Peterborough, ON K9J 7B8, Canada
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Shaw HA, Preston MD, Vendrik KEW, Cairns MD, Browne HP, Stabler RA, Crobach MJT, Corver J, Pituch H, Ingebretsen A, Pirmohamed M, Faulds-Pain A, Valiente E, Lawley TD, Fairweather NF, Kuijper EJ, Wren BW. The recent emergence of a highly related virulent Clostridium difficile clade with unique characteristics. Clin Microbiol Infect 2019; 26:492-498. [PMID: 31525517 PMCID: PMC7167513 DOI: 10.1016/j.cmi.2019.09.004] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2019] [Revised: 09/06/2019] [Accepted: 09/07/2019] [Indexed: 01/06/2023]
Abstract
OBJECTIVES Clostridium difficile is a major global human pathogen divided into five clades, of which clade 3 is the least characterized and consists predominantly of PCR ribotype (RT) 023 strains. Our aim was to analyse and characterize this clade. METHODS In this cohort study the clinical presentation of C. difficile RT023 infections was analysed in comparison with known 'hypervirulent' and non-hypervirulent strains, using data from the Netherlands national C. difficile surveillance programme. European RT023 strains of diverse origin were collected and whole-genome sequenced to determine the genetic similarity between isolates. Distinctive features were investigated and characterized. RESULTS Clinical presentation of C. difficile RT023 infections show severe infections akin to those seen with 'hypervirulent' strains from clades 2 (RT027) and 5 (RT078) (35%, 29% and 27% severe CDI, respectively), particularly with significantly more bloody diarrhoea than RT078 and non-hypervirulent strains (RT023 8%, other RTs 4%, p 0.036). The full genome sequence of strain CD305 is presented as a robust reference. Phylogenetic comparison of CD305 and a further 79 previously uncharacterized European RT023 strains of diverse origin revealed minor genetic divergence with >99.8% pairwise identity between strains. Analyses revealed distinctive features among clade 3 strains, including conserved pathogenicity locus, binary toxin and phage insertion toxin genotypes, glycosylation of S-layer proteins, presence of the RT078 four-gene trehalose cluster and an esculinase-negative genotype. CONCLUSIONS Given their recent emergence, virulence and genomic characteristics, the surveillance of clade 3 strains should be more highly prioritized.
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Affiliation(s)
- H A Shaw
- Department of Pathogen Molecular Biology, London School of Hygiene and Tropical Medicine, London, UK; Division of Bacteriology, National Institute for Biological Standards and Controls, South Mimms, Potters Bar, UK
| | - M D Preston
- Department of Pathogen Molecular Biology, London School of Hygiene and Tropical Medicine, London, UK; Analytical Biological Service Division, National Institute for Biological Standards and Controls, Potters Bar, UK
| | - K E W Vendrik
- National Reference Laboratory for CDI Surveillance, Department of Medical Microbiology and RIVM, Leiden University Medical Centre, Leiden, the Netherlands
| | - M D Cairns
- Department of Pathogen Molecular Biology, London School of Hygiene and Tropical Medicine, London, UK; Public Health Laboratory London, Division of Infection, The Royal London Hospital, London, UK
| | - H P Browne
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, UK
| | - R A Stabler
- Department of Pathogen Molecular Biology, London School of Hygiene and Tropical Medicine, London, UK
| | - M J T Crobach
- National Reference Laboratory for CDI Surveillance, Department of Medical Microbiology and RIVM, Leiden University Medical Centre, Leiden, the Netherlands
| | - J Corver
- National Reference Laboratory for CDI Surveillance, Department of Medical Microbiology and RIVM, Leiden University Medical Centre, Leiden, the Netherlands
| | - H Pituch
- Department of Medical Microbiology, Medical University of Warsaw, Warsaw, Poland
| | - A Ingebretsen
- Department of Microbiology, Oslo University Hospital, Oslo, Norway; Department of Infection Prevention, Oslo University Hospital, Oslo, Norway
| | - M Pirmohamed
- Department of Molecular and Clinical Pharmacology, The University of Liverpool, Liverpool, UK
| | - A Faulds-Pain
- Department of Pathogen Molecular Biology, London School of Hygiene and Tropical Medicine, London, UK
| | - E Valiente
- Department of Pathogen Molecular Biology, London School of Hygiene and Tropical Medicine, London, UK
| | - T D Lawley
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, UK
| | | | - E J Kuijper
- National Reference Laboratory for CDI Surveillance, Department of Medical Microbiology and RIVM, Leiden University Medical Centre, Leiden, the Netherlands
| | - B W Wren
- Department of Pathogen Molecular Biology, London School of Hygiene and Tropical Medicine, London, UK.
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Preston MD, Smemo KA, McLaughlin JW, Basiliko N. Peatland microbial communities and decomposition processes in the james bay lowlands, Canada. Front Microbiol 2012; 3:70. [PMID: 22393328 PMCID: PMC3289907 DOI: 10.3389/fmicb.2012.00070] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2011] [Accepted: 02/10/2012] [Indexed: 11/13/2022] Open
Abstract
Northern peatlands are a large repository of atmospheric carbon due to an imbalance between primary production by plants and microbial decomposition. The James Bay Lowlands (JBL) of northern Ontario are a large peatland-complex but remain relatively unstudied. Climate change models predict the region will experience warmer and drier conditions, potentially altering plant community composition, and shifting the region from a long-term carbon sink to a source. We collected a peat core from two geographically separated (ca. 200 km) ombrotrophic peatlands (Victor and Kinoje Bogs) and one minerotrophic peatland (Victor Fen) located near Victor Bog within the JBL. We characterized (i) archaeal, bacterial, and fungal community structure with terminal restriction fragment length polymorphism of ribosomal DNA, (ii) estimated microbial activity using community level physiological profiling and extracellular enzymes activities, and (iii) the aeration and temperature dependence of carbon mineralization at three depths (0-10, 50-60, and 100-110 cm) from each site. Similar dominant microbial taxa were observed at all three peatlands despite differences in nutrient content and substrate quality. In contrast, we observed differences in basal respiration, enzyme activity, and the magnitude of substrate utilization, which were all generally higher at Victor Fen and similar between the two bogs. However, there was no preferential mineralization of carbon substrates between the bogs and fens. Microbial community composition did not correlate with measures of microbial activity but pH was a strong predictor of activity across all sites and depths. Increased peat temperature and aeration stimulated CO(2) production but this did not correlate with a change in enzyme activities. Potential microbial activity in the JBL appears to be influenced by the quality of the peat substrate and the presence of microbial inhibitors, which suggests the existing peat substrate will have a large influence on future JBL carbon dynamics.
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Affiliation(s)
- Michael D Preston
- Department of Geography, University of Toronto Mississauga Mississauga, ON, Canada
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Preston MD, Eimers MC, Watmough SA. Effect of moisture and temperature variation on DOC release from a peatland: conflicting results from laboratory, field and historical data analysis. Sci Total Environ 2011; 409:1235-1242. [PMID: 21237500 DOI: 10.1016/j.scitotenv.2010.12.027] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2010] [Revised: 10/26/2010] [Accepted: 12/17/2010] [Indexed: 05/30/2023]
Abstract
Peatlands are large repositories of atmospheric carbon and concern has been raised over the stability of this carbon store because increasing dissolved organic carbon (DOC) concentrations have been observed in peatland drainage waters. A number of potential causes have been proposed in the literature, and conflicting results among studies conducted at different spatial and temporal scales suggest that the methodological approach may be an important confounding factor. The objective of this study was to determine the influence of moisture and temperature on DOC release from a south-central Ontario peatland during the fall (a major export period) following three commonly used approaches: laboratory microcosms, an intensive field study and analysis of long-term data (1980-2008). The effect of variations in temperature and moisture differed among microcosm, field study and analysis of the long-term record. Water content was important at the microcosm scale as DOC concentration and aromaticity increased with peat water-saturation. Drought caused a decrease in DOC concentration and pH, and an increase in sulphate and base cation concentrations. In contrast, the field study indicated that DOC concentration was strongly associated with temperature, and weakly correlated (negatively) with stream discharge. Average fall DOC concentration (but not export) increased over the 29 year record, and was correlated with fall discharge and precipitation (negative) and summer precipitation and fall stream pH (positive). As no common strong predictor of fall DOC was found at three scales of investigation at a single, well-studied site, it may be unreasonable to expect to identify a universal driver behind the widespread increase in DOC concentration.
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Affiliation(s)
- Michael D Preston
- Environmental and Life Sciences Graduate Program, Trent University, 1600 West Bank Drive, Peterborough, ON K9J7B8, Canada.
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