Methane formation in living trees: a microbial origin.

Visibly healthy hardwood trees located on poorly drained soils contained high pressures of methane. Heartwood from these trees was water-soaked, neutral to alkaline in pH, fetid in odor, and infested with a diverse population of obligately anaerobic bacteria. the bacterium responsible for methane formation in tree. was isolated and characterized as a member of the genus Methanobacterium.