The Riparian Buffer is the natural area surrounding the stream. These zones support the life within the stream in many different ways. Debris from trees which falls into the stream, though it may look untidy, is actually important for stream health. Water creatures feed on bacteria and fungi from decaying leaves and twigs. Larger tree branches which fall into the stream can perform the same function as larger stones, slowing down the water flow in some places, and creating habitats for fish. The trees, shrubs, and grasses growing in the buffer zone provide habitats for amphibians, mammals, and birds. Wetlands in the buffer zone also support wildlife. Perhaps the most important feature of the buffer zone is to filter the sediment, bacteria, and chemicals from runoff. Buffer zones help keep the water in the stream healthy for the creatures which live there.