Roots and fungi accelerate carbon and nitrogen cycling in forests exposed to elevated CO2
Abstract
A common finding in multiple CO2 enrichment experiments in forests is the lack of soil carbon (C) accumulation owing to microbial priming of ‘old’ soil organic matter (SOM). However, soil C losses may also result from the accelerated turnover of ‘young’ microbial tissues that are rich in nitrogen (N) relative to bulk SOM. We measured root-induced changes in soil C dynamics in a pine forest exposed to elevated CO2 and N enrichment by combining stable isotope analyses, molecular characterisations of SOM and microbial assays. We find strong evidence that the accelerated turnover of root-derived C under elevated CO2 is sufficient in magnitude to offset increased belowground inputs. In addition, the C losses were associated with accelerated N cycling, suggesting that trees exposed to elevated CO2 not only enhance N availability by stimulating microbial decomposition of SOM via priming but also increase the rate at which N cycles through microbial pools.
Department
Soil Biogeochemistry and Microbial Ecology
Publication Date
7-8-2012
Journal Title
Ecology Letters
Publisher
Wiley
Digital Object Identifier (DOI)
Document Type
Article
Recommended Citation
Phillips, R.P., Meier, I.C., Bernhardt, E.S., Grandy, A.S., Wickings, K. and Finzi, A.C. (2012), Roots and fungi accelerate carbon and nitrogen cycling in forests exposed to elevated CO2. Ecol Lett, 15: 1042-1049. https://doi.org/10.1111/j.1461-0248.2012.01827.x
Rights
© 2012 Blackwell Publishing Ltd/CNRS