2.3.15 (HL)—Methane production

Methanogens can produce methane when dead organic matter is abundant and oxygen is absent or very limited.

Anaerobic conditions occur in wetlands, flooded rice fields, landfills and ruminant guts. Organic matter alone is not enough: oxygen status and microbial conditions control production.

A waterlogged landfill cell with food waste and little oxygen is more methane-prone than a dry, aerated compost pile.

Oxygen exposure; methanogenesis is favoured when competing aerobic decomposition cannot use the material.

Methane is not produced by every decomposer or in every wet place; check substrate and anaerobic conditions.