|Field Trip - Indiana Dunes National Lakeshore - 5 of 12
By Paul Katula, Dateline: GARY, Ind. (May 27, 2006)
Fallen branches also make the sand sturdier:
Branches often fall off the cottonwood trees. Those branches get buried by new sand and are just as good as the branches of the tree that started underground. This is the driving force of secondary succession: pioneers make the soil suitable for other species, whose seeds might just happen along on a breeze, an insect, the water, or even a human. Once the marram grass and cottonwood trees make the sand stable enough, other plants will be able to survive.