Yes, trees can absorb methane, but whether a given tree pulls methane in or pushes it out depends heavily on where it grows. Trees on well-drained, dry soils tend to act as methane sinks, while trees in waterlogged or swampy soils often do the opposite, channeling methane from saturated ground into the atmosphere. A 2024 study published in Nature confirmed that the woody surfaces of upland trees across tropical, temperate, and boreal forests actively consume atmospheric methane, a role scientists had largely overlooked until recently.
How Trees Consume Methane
Trees don’t absorb methane the way they absorb carbon dioxide during photosynthesis. Instead, the process is driven by microbes living in and on tree bark. Methane-eating bacteria, primarily from a group called Methylomonas, can make up as much as 25% of the total microbial community on bark surfaces. These bacteria use a specialized enzyme to break methane apart, grabbing the carbon for energy and releasing carbon dioxide and water as byproducts.
There’s also a second, less understood mechanism at play. Recent research suggests that methane consumption in tree stems may be partly tied to the tree’s own respiratory processes rather than bark microbes alone. Scientists observed that methane uptake in stems closely mirrors oxygen consumption patterns throughout the day, rising in the early morning as the tree’s metabolism ramps up and declining by midday even though temperatures remain high. If the process were purely microbial, you’d expect it to accelerate with warming. Instead, it slows down, hinting that the tree itself plays a more active role than previously assumed.
Why Location Matters More Than Species
The single biggest factor determining whether a tree absorbs or emits methane is soil moisture. Trees growing in upland forests with well-drained soil sit above ground that already contains its own population of methane-eating microbes. These trees tend to pull methane in through their bark. Trees rooted in wetlands, peatlands, or floodplains, on the other hand, act like chimneys. Waterlogged soil produces methane through decomposition in oxygen-free conditions, and the methane travels up through the tree’s roots and trunk, escaping into the air through the bark and leaves.
Forest soils themselves are a major methane sink, responsible for up to 62% of all methane consumed by soils worldwide. Soil rich in organic carbon enhances methane consumption significantly. One global modeling study estimated that accounting for soil organic carbon increases the calculated forest methane sink by 39%, from roughly 17.5 to 24.3 teragrams of methane per year. That’s a substantial revision that highlights how carbon-rich forest soils supercharge the methane-eating capacity of the whole ecosystem.
The Height Gradient on a Single Tree
Methane behavior isn’t uniform across a tree trunk. Measurements taken at multiple heights on tropical trees show that emissions decline exponentially as you move up the stem. At 35 centimeters above the ground, fluxes averaged about 10 milligrams per square meter per day. By 115 centimeters, that dropped to 26% of the base level. At 5 meters up, emissions were just 3.5% of what they were near the ground.
This pattern makes sense: the lower trunk is closest to soil where methane is produced. Higher up, the bark is exposed to open air, and methane-consuming microbes have more opportunity to intercept gas before it escapes. For upland trees, this gradient actually flips. Researchers in England and Sweden found that methane uptake increased with height above the soil, with the strongest absorption recorded at 2 meters up. The bark higher on the trunk is better ventilated and farther from any soil moisture influence, creating ideal conditions for methane-eating microbes.
Differences Across Climates and Species
Tropical forests show the highest rates of methane uptake on tree surfaces, while temperate and northern boreal forests show smaller but still measurable absorption. In an English woodland, ash trees absorbed an average of about 18.5 micrograms of methane per square meter per hour at 2 meters high, with individual readings as high as 55 micrograms. Sycamore trees at the same site averaged 14 micrograms per hour, but one individual measurement hit 142 micrograms, the highest recorded uptake in the study.
In a Swedish boreal forest, pine stems absorbed roughly 10 micrograms per square meter per hour, while spruce managed only about 3. These differences likely reflect variations in bark texture, moisture retention, and microbial community composition. Rougher, more porous bark provides more surface area and sheltered pockets for methane-eating bacteria to colonize.
Daily and Seasonal Rhythms
Methane uptake follows a daily cycle. Early mornings bring the fastest absorption rates, as rising temperatures boost the tree’s metabolic activity and draw both oxygen and methane into the stem. As the day heats up and the tree begins losing more water through its leaves, uptake tapers off. By midday, absorption has dropped noticeably even though conditions might seem favorable for microbial activity.
Temperature sensitivity also plays a role across seasons. Warmer conditions generally correlate with higher methane uptake, but the relationship isn’t linear. As temperatures climb, the rate of increase in uptake slows down. This contrasts with purely microbial processes, which typically accelerate exponentially with heat. The implication is that the tree’s own physiology acts as a bottleneck, limiting how much methane can be processed during the hottest periods.
What This Means for Forests and Climate
For years, the conversation around trees and methane focused on emissions, particularly from wetland forests and flooded landscapes. The recognition that upland trees actively consume atmospheric methane through their bark surfaces adds a new dimension to how forests regulate greenhouse gases. It’s not just about carbon dioxide storage. Every square meter of bark in a dry forest is a small but real methane filter.
Maintaining and expanding forests on well-drained land strengthens this effect. Healthy soils with high organic carbon content amplify it further, since richer soils support larger and more active populations of methane-consuming microbes both underground and on the trees above. Deforestation removes not only a carbon sink but a methane sink, a dual loss that current climate models are only beginning to fully account for.