We measured fluxes of CO₂ and CH₄ from snags in a Maine forest. CO₂ flux peaked at intermediate soil moisture and high temperatures, while CH₄ flux peaked under wet conditions and high temperature. CH₄ increased most when both temperature and soil moisture were high. As CH₄ emissions rose, CO₂ emissions dropped along the moisture gradient, reflecting changes in microbial activity in wetter conditions. Our study adds to growing evidence that snags are active participants in forest carbon cycling.