Relationship between ecosystem productivity and photosynthetically active radiation for northern peatlands

Authors

S. E. Frolkin, University of New Hampshire, DurhamFollow
J.L. Bubier, University of New Hampshire, DurhamFollow
T.R. Moore, McGill UniversityFollow
T. Ball, McGill UniversityFollow
L.M. Bellisario, McGill UniversityFollow
A. Bhardwaj, McGill UniversityFollow
P. Carroll, University of New Hampshire, DurhamFollow
P.M. Crill, University of New Hampshire, DurhamFollow
Peter M. Lafleur, Trent University, Peterborough, OntarioFollow
J.H. McCaughey, Queen's UniversityFollow
N.T. Roulet, McGill UniversityFollow
A. E. Suyker, University of Nebraska-LincolnFollow
S.B. Verma, University of Nebraska - LincolnFollow
J.M. Waddington, McMaster UniversityFollow
G.J. Whiting, Christopher Newport UniversityFollow

Document Type

Article

Date of this Version

3-1998

Citation

1998 by the American Geophysical Union.

Comments

Global Biogeochemical cycles, Vol. 12, No. 1, Pages 115-126, March 1998

Abstract

We analyzed the relationship between new ecosystem exchange of carbon dioxide (NEE) and irradiance (as photosynthetic photon flux density of PPFD), using published and unpublished data that have been collected during midgrowing season for carbon balance studies at seven peatlands in North America and Europe. NEE measurements included both eddy-correlation tower and clear, static chamber methods, which gave very similar results. Data were analyzed by site, as aggregated data set for all peatland type (bog, poor fen, rich fen, and all fens) and as a single aggregated data set for all peatlands. In all cases, a fit with a rectangular hyperbola (NEE = PPFD P _max (PPFD + P_MAX) + R) better described the NEE-PPFD relationships ,while bogs had lower respiration rates (R = -2.0 umol m^-2 s^-1 for bogs and -2.7 umol m^-2 s^-1 for fens) and lower NEE at moderate and high light levels (P_{max =} 5.2 umol m^-2 s^-1) than the upland exosystems (closed canopy forest, grassland, and cropland) summarized by Ruimy et al. [1995]. Despite this low productivity, northern peatland soil carbon pools are generally 5-50 times larger than upland ecosystems because of slow rates of decomposition caused by litter quality and anaerobic, cold soils.