A type of man-made ecosystem that is commonly found in urban areas is a roof garden. Roof gardens are usually planted on top of buildings and can provide a habitat for a variety of plants and animals. They can also help reduce the heat in urban areas and improve air quality. Rooftop gardens can be designed in a variety of ways, and can include a mix of plants, seating areas, and even small ponds. They can be a refreshing and peaceful oasis in an otherwise concrete jungle.