Plant functional group identity influences short-term peatland ecosystem carbon flux: evidence from a plant removal experiment
Article first published online: 18 DEC 2008
© 2008 The Authors. Journal compilation © 2008 British Ecological Society
Volume 23, Issue 2, pages 454–462, April 2009
How to Cite
Ward, S. E., Bardgett, R. D., McNamara, N. P. and Ostle, N. J. (2009), Plant functional group identity influences short-term peatland ecosystem carbon flux: evidence from a plant removal experiment. Functional Ecology, 23: 454–462. doi: 10.1111/j.1365-2435.2008.01521.x
- Issue published online: 13 MAR 2009
- Article first published online: 18 DEC 2008
- Received 19 February 2008; accepted 12 November 2008; Handling Editor: Ken Thompson
- carbon cycle;
- soil respiration;
- stable isotope pulse labelling;
- 1Northern hemisphere peatlands are globally important stores of organic soil carbon. We examined effects of plant functional group identity on short-term carbon (C) flux in an ombrotrophic peatland in northern England, UK, by selectively removing one of each of the three dominant plant functional groups (ericoid dwarf-shrubs, graminoids and bryophytes). Carbon dynamics were quantified by a combination of CO2 flux measurements and 13CO2 stable isotope pulse labelling approaches.
- 2Significant effects of plant functional group removals on CO2 fluxes and tracer 13C uptake and turnover were detected. Removal of ericoid dwarf-shrubs had the greatest influence on gross CO2 flux, increasing rates of respiration and photosynthesis by > 200% relative to the undisturbed control. After pulse labelling with 13CO2, we found that turnover of recent photosynthate, measured as respired 13CO2, was also greatest in the absence of dwarf-shrubs.
- 3Analysis of 13C tracer enrichment in leaf tissues from all plant removal treatments showed that the rate of fixation of 13CO2 and turnover of 13C labelled photosynthate in leaf tissue was greatest in graminoids and lowest in bryophytes. Furthermore, graminoid leaf 13C enrichment was greatest when growing in the absence of dwarf-shrubs, suggesting that the presence of dwarf-shrubs reduced the photosynthetic activity of graminoids.
- 4We conclude that plant functional groups differentially influence the uptake and short-term flux of carbon in peatlands, suggesting that changes in the functional composition of vegetation resulting from global change have the potential to alter short-term patterns of carbon exchange in peatland.