Listen to part of a lecture in an environmental science class. Professor: Today we're discussing the role of wetlands, specifically peatlands, in carbon storage. Peatlands cover only about three percent of Earth's land surface, yet they store nearly thirty percent of all soil carbon. This is because peat—partially decomposed plant material—accumulates over thousands of years in waterlogged, acidic conditions that slow decomposition. However, when peatlands are drained for agriculture or peat extraction, the peat is exposed to oxygen, and microbes rapidly break it down, releasing carbon dioxide into the atmosphere. In fact, drained peatlands account for about five percent of global greenhouse gas emissions. Some countries are now restoring these areas by rewetting them—blocking drainage channels and allowing water levels to rise. This not only stops carbon release but also encourages new peat formation. However, restoration is expensive and can conflict with local economic interests. So, while peatlands are vital for climate regulation, their management requires careful balance.
❓ 题目 What is the main reason peatlands store large amounts of carbon?
A. They cover a vast area of Earth's surface.
B. Their wet, acidic conditions slow down decomposition.
C. They contain large amounts of fossil fuels.
D. They are located in cold climates that preserve organic matter.
✅ 正确答案
Their wet, acidic conditions slow down decomposition.