A wetland forest in Tupana, Brazil. Amauri Aguiar/Flickr

Scientists Zero in on Trees as a Surprisingly Large Source of Methane

Recent research is showing that trees, especially in tropical wetlands, are a major source of the second most important greenhouse gas in the atmosphere, methane. The knowledge that certain woodlands are high methane emitters should help guide reforestation projects in many parts of the world.

By Fred Pearce

There are many mysteries in the Amazon. Until recently, one of the most troubling was the vast methane emissions emerging from the rainforest that were observed by satellites but that nobody could find on the ground. Around 20 million tons was simply unaccounted for.

Then Sunitha Pangala, a British post-doc researcher, spent two months traveling the Amazon’s waterways strapping gas-measuring equipment to thousands of trees. She found that trees, especially in the extensive flooded forests, were stimulating methane production in the waterlogged soils and mainlining it into the atmosphere…