Fluxes of CO₂, N₂O and CH₄by²²²Rn and chamber methods in cold-temperate grassland soil, northern Japan

Abstract

This study conducted flux measurements of carbon dioxide (CO 2 ), nitrous oxide (N 2 O) and methane (CH 4 Rn method were in good agreement with those of the static chamber method, within the observed range of error, suggesting a high correlation coefficient of > 89% between the methods. Also, the temperatures of air and soil at 5-cm depth played a significant role in determining the fluxes of CO 2 and CH 4 measured by the 222 Rn and chamber methods; meanwhile, the N 2 O flux displayed an inverse exponential relation to temperature. This suggests that N 2 O flux may be regulated by other factors such as soil water content and soil oxygen concentration. The contribution of winter fluxes of CO 2 , N 2 O and CH 4 corresponded to 9, 51 and 3% of the annual fluxes of CO 2 , N 2 O and CH 4 , respectively, reflecting higher winter N 2 O production due to the constraint of oxygen in soil.)

Memory effects on greenhouse gas emissions (CO<sub>2</sub>, N<sub>2</sub>O and CH<sub>4</sub>) following grassland restoration?

“…Our study found opposing net fluxes of methane when comparing chamber fluxes (2010 and 2011) with eddy covariance methane fluxes. Published studies carried out to investigate grassland methane emissions with chambers mostly show a net uptake of methane (Beyer et al, 2015;Chiavegato et al, 2015;Kim and Tanaka, 2015;Wei et al, 2015), while eddy covariance based studies often show a net release of methane (Baldocchi et al, 2012;Dengel et al, 2011;Hörtnagl et al, 2018;Kroon et al, 2010). We identified three primary reasons for this discrepancy: (1) the difference in spatial scales that the individual methods investigate;…”