Such mires are called quaking bogs. Under certain conditions, especially deforestation, sedge and sphagnum invade higher ground. The peat they form becomes compressed and blocks the drainage of water. These are called blanket mires or moors. Because of their highly acidic nature, wetness, low temperature, and absence of oxygen, northern bogs have become a repository of past life.
Pollen grains preserved in bogs provide clues to past vegetation and climate.
In northern Europe, well-preserved bodies, clothing, food, tools, and artifacts reveal something of human life here 2000 years ago. Peat has been cut for centuries as fuel. Because of commercial excavation of this important energy source, peatlands are now becoming endangered ecosystems.