Plant‐Induced Changes Mediate Belowground Carbon Cycling in an Experimentally Warmed Peatland
| Authors: | R. M. Wilson, C. C. Petro, M. M. Tfaily, V. G. Salmon, R. J. Norby, K. Duchesneau, J. Birkebak, K. N. Smith, G. Makke, K. E. Briley, S. H. Bosman, S. B. Hodgkins, T. Song, N. A. Griffiths, Stephen D. Sebestyen, P. J. Hanson, C. W. Schadt, J. E. Kostka, J. P. Chanton |
| Year: | 2026 |
| Type: | Scientific Journal |
| Station: | Northern Research Station |
| DOI: | https://doi.org/10.1029/2024JG008573 |
| Source: | Journal of Geophysical Research: Biogeosciences |
Abstract
Warming and elevated atmospheric CO2 profoundly impact peatland ecosystems, particularly through changes in plant species composition. Plants regulate the initial input of organic compounds to peatland belowground systems, controlling the availability of electron donors and electron acceptors that fuel microbially mediated organic matter decomposition to CO2 and CH4. However, explicit links between porewater CO2 and CH4 dynamics and plant‐derived chemical compounds remain relatively undefined. In a whole ecosystem warming experiment, we investigated how warming affects plant leaf chemical composition and species assemblages, and how the alteration of leaf‐derived organic compounds supplied to the subsurface impacts belowground CO2 and CH4 production. While earlier studies at our site found no temperature‐dependent changes in CH4 production pathways, our extended timeseries has revealed increased acetoclastic methanogenesis at higher temperatures in certain peat depths, correlated with elevated porewater phenolics. These changes appear driven by the observed increased plant productivity and altered vegetation inputs, which accelerate decomposition and fuel CH4 production through enhanced substrate availability. We observed warming‐induced changes in molecular composition both between and within plant species, suggesting that plant‐mediated controls on belowground carbon processing are more complex than previously recognized.
Plain Language Summary: Climate warming and higher air carbon dioxide levels are expected to affect plant communities particularly in climate‐sensitive ecosystems such as peatlands. Plants control the input of organic carbon to the belowground environment. Microbial growth in peat soils is dependent on plant‐derived organic carbon inputs which result in the production of carbon dioxide and methane. In an experimentally warmed peatland ecosystem, we demonstrate the links between changing plant communities, as well as the response of individual species to warming, the belowground carbon inputs and ultimately the production of these gases. What is most interesting, is that even should the plant community remain seemingly unchanged, the chemical composition of individual plant species may be altered under warmer conditions such that greenhouse gas production is stimulated.