Low-lying, flat areas next to rivers or lakes, forming fertile floodplains rich in nutrients from periodic flooding, support unique bottomland hardwood forests with trees like cypress and oak that tolerate wet soils, and serve as crucial habitats for diverse wildlife, often characterized by their transition from wet swamps to drier woodlands. They are defined by seasonal inundation and nutrient-rich alluvial soils, making them distinct ecosystems within broader landscapes, especially prominent in the southeastern US.