The Lake - A Walk through Time
Illinois State Museum
You can experience change through time and variation across space at the same time by starting at the water and walking inland. Because of the way this ridge plain formed, the beach is the youngest environment. As you walk away from it, each ridge you cross is older than the one before. Older ridges have supported vegetation longer than the ones before them and typically have more species.
The beach is a harsh place, with blowing wind and sand and crashing waves. Only the toughest plants can survive here.
The ridge away from the beach, the foredune, is older than the beach. Grasses grow here. They stabilize the dune, create shade, retain moisture, and add nutrients to the soil so other plants can take hold.
The next area is even older. It is a sand prairie. Generations of grasses have created a thin soil and improved conditions for plants.
Still farther back, the land is even older. The soil is deeper and more
fertile. Tree saplings take root, and sand prairie gives way to an
open oak forest.