Changes in seasonal soil respiration with pasture conversion to forest in Atlantic Canada
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This study compares approximately weekly soil respiration across two forest–pasture pairs with similar soil, topography and climate to document how conversion of pasture to forest alters net soil CO2 respiration. Over the 2.5 year period of the study, we found that soil respiration was reduced by an average of 41% with conversion of pasture to forest on an annual basis. Both pastured sites showed similar annual soil respiration rates. Comparisons of the paired forests, one coniferous and the other broadleaf, only showed a significant difference over one annual cycle. Enhanced soil respiration in pastures may be the result of either enhanced root respiration and/or microbial respiration. Differences in pasture–forest soil respiration were primarily observed during the July through September summer period at all sites, suggesting that this is the critical period for observing and documenting differences. Evaluation of the soil microclimatic controls on soil respiration suggest that soil temperature exerts a major control on this process, and that examining these relationships on a seasonal rather than weekly basis provides the strongest relationships in poorly drained soils. Consistently greater pastured site Q 10s (2.52;2.42) than forested site Q 10s (2.27; 2.17) were observed, with paired-site differences of 0.25.
KeywordsCarbon cycle Soil respiration Soil carbon dioxide Afforestation
This research was supported by the Canadian Foundation for Climate and Atmospheric Sciences (CFCAS), the Natural Sciences and Engineering Research Council of Canada (NSERC), and the Atlantic Canada Opportunities Agency (ACOA). Amanda Diochon provided the vegetation site descriptions and many other members of the Environmental Sciences Research Centre at StFXU contributed to the collection and analysis of this data. The comments of reviewers are gratefully acknowledged.
- Cann DB, Hilchey JD (1954) Soil survey of Antigonish County. Nova Scotia, Truro, Nova ScotiaGoogle Scholar
- Fahey TJ, Siccama TG, Driscoll CT, Likens GE, Campbell J, Johnson CE, Battles JJ, Aber JD, Cole JJ, Fisk MC, Groffman PM, Hamburg SP, Holmes RT, Schwarz PA, Yanai RD (2005) The Biogeochemistry of Carbon at Hubbard Brook. Biogeochemistry 775:109–176, doi:10.1007/s10533-004-6321-yGoogle Scholar
- Gleason SM, Ewel KC (2002) Organic matter dynamics on the forest floor of a Micronesian mangrove forest: an investigation of species composition shifts. Biotropica 34(2):190–198Google Scholar
- Hogberg P, Nordgrem A, Buchmann N, Taylor AFS, Ekblad A, Hogberg MN, Nyberg G, Ottosson-Lofvenius M, Read DJ (2001) Large-scale woodland girdling shows that current photosysnthesis drives soil respiration. Nature 411:789–792Google Scholar
- IPCC TAR (Intergovernmental Panel on Climate Change, Third Assessment Report). In: Houghton JT, Ding Y, Griggs DJ, Noguer M, van der Linden PJ, Dai X, Maskell K, Johnson CA (eds) Climate Change 2001: The Scientific Basis. Cambridge Univ. Press, 2001Google Scholar
- Johnson RS (1986) Forests of Nova Scotia. Four East Publications. Halifax NS, CanadaGoogle Scholar
- Ollinger SV., Smith ML.,Martin ME., Hallett RA.,Goodale CL.,Aber JD (2002) Regional variation in foliar chemistry and N cycling among forests of diverse history and composition. Ecology 83(2): 339–355Google Scholar
- Raich JW, Schlesinger WH (1992) The global carbon dioxide flux in soil respiration and its relationship to vegetation and climate Tellus 44b:81–99Google Scholar
- Risk D, Kellman L, Beltrami H (2002a) Carbon dioxide in soil profiles: production and temperature dependency. Geophys Res Lett 29(6):1087, doi:10.1029/2001GL014002Google Scholar
- Risk D, Kellman L, Beltrami H (2002b) Soil CO 2 production and surface flux at four climate observatories in eastern Canada. Global Biogeochem Cycles 16(4):1122, doi:10.1029/2001GB001831Google Scholar