Cycling of important greenhouse gases methane (CH4) and nitrous oxide (N2O) in terrestrial ecosystems has traditionally focused on gas exchange between the soil surface and the atmosphere. Recent findings are now suggesting that trees may play an important, and until recently overlooked, role in the net exchange of these greenhouse gases. Trees occupying permanently and seasonally inundated soils may be important conduits of soil-produced CH4 and N2O to the atmosphere, whereas trees occupying drier soils may also be playing a role in the net gas exchange via in-situ production of these gases. Forests are also vulnerable to fire which itself is a poorly quantified source of especially CH4. This session seeks to bring together researchers working on the exchange of CH4 and N2O in forest ecosystems at any relevant scale, and from the full climatic and hydrological forest range. We therefore welcome contributions on microbial processes in soils, plant tissues and microtopographic forms, flux measurements on the forest floor, on tree stems and at the leaf and canopy level; micrometeorological measurements using flux towers, and satellite, inverse and numerical modelling studies that seek to integrate our understanding of CH4 and N2O exchange in forest ecosystems.