Kirschbaum, M.U.F., Niinemets, U., Bruhn, D.,
Winters, A.J. (2007). How Important Is Aerobic Methane Release by Plants? Functional Plant Science and Biotechnology
1: 138-145.
Abstract. The first research paper describing aerobic
methane release from living plants and dead organic matter was published in
early 2006. These original findings have yet to be independently repeated and
confirmed, and the only other detailed study that has been published did not
find significant aerobic emissions of methane. Concerns remain about possible
artefacts, especially with respect to methane adsorption and desorption.
Several questions are yet to be answered, such as identification of a plausible
biochemical mechanism for the process, how CH4 emissions might
change with light, temperature or the physiological state of leaves, whether
emissions change over time under constant conditions, whether they are related
to photosynthesis and how they relate to the chemical composition of biomass.
Various studies have assessed the likely magnitude of aerobic methane release
within a global context. Different estimates based on more or less
sophisticated approaches have all indicated that the magnitude of aerobic
methane release must be relatively moderate and contribute between 0-10% of
modern and 0-30% of pre-industrial/pre-agricultural methane emissions. In the
context of land-use change, consideration of aerobic CH4 emissions
from different plant types is only a small factor for overall greenhouse gas
balances. Any carbon-offset benefit from planting trees is likely to be about
100 times as effective as any possible detrimental effect due to increased
aerobic methane release. Land-use change, including the draining of wetlands,
the establishment of paddy rice farming, or the introduction of ruminant
animals, would produce emission changes that significantly outweigh any
potential changes arising from differences in aerobic methane release by
different plant types.
Keywords:
adsorption, aerobic, climate-change mitigation, desorption, dissolution, global
budget, Kyoto Protocol, land-use change, methane oxidation, trace gas
[Miko Kirschbaum’s home
page] [Back to Miscellaneous Studies]