Trend analysis of methane uptake in 13 forest soils based on up to 24 years of field measurements in south-west Germany

Le résumé fourni par la source

Methane (CH₄) plays a crucial role in global climate dynamics as a potent greenhouse gas. Forest soils are the most important terrestrial CH 4 -sinks, yet long-term trends in CH 4 -uptake remain underexplored, due to the lack of long-term field measurements on the same site. This study presents findings from a soil gas monitoring programme in 13 forest soils in south-west Germany of up to 24 years, which represents currently the worldwide largest dataset of continuous CH 4 -fluxes. CH 4 -uptake was calculated from soil gas profiles and validated through chamber measurements. CH 4 -uptake ranged from 0.55 to 3.31 nmol m⁻s⁻¹ with significant site-specific variability, and was on average 1.40 ± 1.29 nmol m⁻² s⁻¹. Our analysis shows an increase in CH 4 -uptake of 3% per year on average. During the observation period annual precipitation decreased and soil moisture as well, while soil temperatures increased, what we identified as the most probable explanation of the observed trend. The observed long-term trends in CH 4 -uptake are in contrast to the latest studies. However, they perfectly agree in the explanation of the observed trend, which is the trend in local precipitation patterns, just that the local precipitation patterns followed different directions. Thus, this study demonstrates the value of long-term data sets as well as the importance climate projections that also include reliable precipitation predictions.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.