Increased temperatures and changes in vegetation patterns are expected to dramatically alter northern ecosystems the next few decades. Little is known about how this translates into relative rates of formation and decomposition of soil organic C, but a general belief is that increasing temperatures and rising concentrations of atmospheric CO2 will be partly mitigated by elevated C sequestration.
However, results from CO2 fertilization and warming experiments vary widely between prolonged, temporary and no stimulation of plant growth and C sequestration. There is therefore a discrepancy between theory and data. Why is this? One answer is that current theories and models fail to accurately address three major factors of importance for C cycling and sequestration:
My research aims at resolving the importance of these factors. More specifically I aim at identifying links between above ground biota and belowground C and N turnover, but also to determine the relative importance of fungi, bacteria and archaea for the same processes, and the ways in which this is modulated.
Bengtson, P., Basiliko, N., Dumont, M.G., Hills, M., Murrell, J.C., Roy, R, and Grayson, S.J. 2009. Links between methanotroph community composition and CH4 oxidation in a pine forest soil. FEMS Microbiology Ecology 70, 356-366
Bengtson, P., and Bengtsson, G. 2007. Rapid turnover of DOC in temperate forests accounts for increased CO2 production at elevated temperatures. Ecology Letters 10, 783-790
Bengtson, P., Falkengren-Grerup, U., and Bengtsson, G. 2006. Spatial distribution of plants and gross N transformation rates in a forest soil. Journal of Ecology 94, 754-764
PhD students, main supervisor:
PhD students, ext supervisor:
Carolyn Churchland, University of British Columbia, BC, Canada