Is methane released from the forest canopy?

iForest - Biogeosciences and Forestry

Larsen KS¹  Pilegaard K¹  Ambus P¹  Ibrom I¹  Bruhn D¹  Mikkelsen TN¹ 

[1] Risø National Laboratory for Sustainable Energy, Technical university of Denmark, Biosystems Division, BIO-309, P.O. Box 49, Frederiksborgvej 399, DK-4000 Roskilde (Denmark);

关键词: Methane;    CH4 emission;    Forest canopy;    Fagus sylvatica L.;   

DOI  :  10.3832/ifor0591-004

来源: DOAJ

【 摘 要 】

Laboratory experiments show that rates of CH4 emission from plant material depend exponentially on temperature and linearly on UV irradiance. The UV irradiance shall be spectrally weighted and shorter wavelengths results in higher CH4 emissions. Global upscaling models for estimating aerobic CH4, based on lab results, have be conducted with varying results, but until now field measurements based on profile and eddy covariance measurements have failed to show CH4 emissions from forest canopies. To detect CH4 production or consumption in the canopy of a beech stand we connected a CH4 analyzer to a canopy air profile system that samples air below and above the canopy from seven different heights. A profile system with many vertical sample points can detect gas concentration gradients with a high sensitivity only under conditions with no or little air movements. Under these conditions we found indications of periodic CH4 emissions in the canopy, but more data need to be analyzed before the magnitude of the canopy source of CH4 can be established.

【 授权许可】

Unknown