The four stages of pond succession are pond pioneers, submergent vegetation appearing around the pond, decaying matter raising the pond floor and a marsh being created. Ponds are shallow holes where water collects. They are formed by geological events.
Ponds fill with dirt and debris and eventually transform into soil. This process takes hundreds of years. Pond pioneers are animals that live in the pond and the seeds that birds drop into it. Plants grow along the bottom of the pond, then die and decompose building layers and raising the floor. The plants grow all the way across the floor, creating a marsh. When trees grow in the water, the marsh becomes a swamp. The swamp may dry out and become a forest or grassland.