A fen is a type of wetland that is characterized by its waterlogged soil and rich biodiversity. It typically has a mix of freshwater and nutrient-rich water, which supports a variety of plant and animal life. Fens are often found in low-lying areas and can be home to grasses, sedges, and various flowering plants. Fens play an important role in the ecosystem by filtering water, storing carbon, and providing habitat for wildlife. They are different from marshes and swamps, as fens are usually less acidic and have a higher nutrient content. Protecting fens is crucial for maintaining biodiversity and combating climate change.