Starts with open water, then reeds that grow around the edge of the open water begin to spread as they reproduce more. This begins to fill up the water, as the dead plant matter decomposes and replaces the water with soil. Next, small trees and bushes being in to populate the area, because seed from nearby trees are transported there and can now grow, as there is soil. Over time, the trees grow even more and produce woodland, then eventually, very large trees start to grow such as oak trees.
