Forest soils at 13 sites in southwest Germany soaked up about 3% more methane each year over up to 24 years of measurements

Forest soils at 13 sites in southwest Germany took up about 3% more methane each year on average, across measurement records that run up to 24 years. The finding comes from researchers at the University of Göttingen and the Baden-Württemberg Forest Research Institute, known as FVA, and it cuts against the direction many international analyses have pointed.

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Methane is a potent greenhouse gas, and forest soils are one of its natural sinks, because microbes living in the ground consume it. The German team asked whether that sink has been shrinking under climate change, and for these sites the answer was no.

The 13 sites and the 24-year record

According to the University of Göttingen press release, the data came from 13 forest plots in southwest Germany, monitored for periods of up to 24 years as part of the FVA’s long-running soil gas monitoring program. Soil air was sampled every two weeks through thin tubes inserted into the ground and analyzed in a laboratory. As an independent check, the team placed airtight chambers on the soil surface to measure how gas concentrations changed and how much methane the soil removed. The two methods let the researchers cross-check the rates they calculated from the buried tubes against direct measurements at the surface, and the FVA program supplied the continuous record that made a trend analysis possible in the first place, since few forest sites in any country have been sampled this regularly for this long.

The paper, by Verena Lang, Valentin Gartiser, Peter Hartmann and Martin Maier, is titled “Trend analysis of methane uptake in 13 forest soils based on up to 24 years of field measurements in south-west Germany” and appeared in Agricultural and Forest Meteorology; its DOI lists volume 375, article 110823. The study’s framing is careful: up to 24 years, because not every site was measured for the full period, and 13 soils, not forests in general.

Drier, warmer soils and the microbes in them

The researchers tie the rising uptake to lower rainfall and higher temperatures over the period. Drier soil has more air-filled pores, so methane moves deeper before microbes consume it, and warmer conditions can speed that microbial activity somewhat. In plain terms, a drier forest floor can act as a better sponge for methane, because the gas has more open channels to travel down before it reaches the microbes that consume it. The ScienceDaily version of the release, dated Oct. 17, carries the same explanation.

Martin Maier, the study’s lead researcher in the University of Göttingen’s Department of Crop Sciences, who earlier took part in the FVA’s soil gas monitoring, said the team observed a significant long-term increase in methane uptake in the forest areas it studied. He argued that measurements repeated over many years, and monitoring programs that keep running, are indispensable for judging the real effects of climate change. That argument is the study’s main methodological point: a few years of data at a few plots could show almost any direction, while a record spanning more than two decades can separate a trend from year-to-year noise.

A result that contradicts other studies

The finding sits awkwardly beside earlier work. The release cites the largest U.S. study to date, which reported a decline in methane uptake of up to 80% linked to increasing rainfall, the opposite of the German pattern. Several international meta-analyses have also concluded that forest soil methane absorption is declining, and the German authors argue that broad averages like these can hide regional differences.

The Envirotec write-up from March 17 adds that results varied significantly between the study locations, and that the evidence comes from one region, so it may not generalize to other forests. The U.S. study’s opposite result suggests that the effect of rainfall may depend on location and climate, which is consistent with the German authors’ point that regional differences can disappear inside broad averages.

What the authors do not claim

The authors stress that the result does not mean climate change is beneficial for forests overall. Effects depend on local climate and soil conditions, and the rise applies to the drier, warmer conditions the sites experienced. The Microbiologist summary stresses that the increase is an average across sites, and Envirotec notes that drier and warmer conditions may become more common in places but are not guaranteed. Put together, the cautions limit what can be said: the 3% figure describes these 13 plots, not a national trend and not a forecast for forests elsewhere.

The timeline of the coverage is worth separating from the timeline of the science. The paper carries a 2025 volume date, the University of Göttingen release is dated Jan. 28, 2026 on its own site, Envirotec wrote it up in March, and the ScienceDaily copy appeared in October. The 3% figure and the 24-year span are unchanged across every version.

This article was produced with the assistance of AI and reviewed by Morning Overview editors prior to publication.

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