Dune Ecology Basswood Tree - Stop #6

Gnarly knotted Basswood Tree

NPS Photo/ K. Maisano

Quick Facts

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Historical/Interpretive Information/Exhibits

To survive in the dunes is no easy task. Flora and fauna deal with strong sunlight, poor soils, and constant winds. The wind action alone can dry out plants, expose root systems, or even completely bury vegetation, including trees.

The cottonwood is the only common tree of the dunes and is well adapted to the dune environment. Because it grows fast, the tree can keep pace with burial by sand. Cottonwood trees grow in a cluster. They reproduce by cloning, sprouting new trunks from roots. The network of roots helps to hold the sand in place, and the tree itself acts as a windbreak, stabilizing the dunes. The dense root networks of various grasses also hold the sand in place. Once the dune is stabilized, new plants can begin growing on it, plants which are not able to survive on an active dune. Common juniper, the evergreen shrub growing among the grasses, is one of the typical plants of stabilized dunes.

The dunes cover just a small area because they depend on strong winds off Lake Michigan to exist. The active dune zone extends for only about a mile from the lake. Further inland, the wind loses its energy and can no longer build dunes.
The basswood tree across the road is a good example of the contest between trees and vegetation and the wind. Wind action has been threatening the tree's stability. If you were that tree, how much longer do you think you could keep your balance and stay standing?

As you continue on to the Lake Michigan Overlook, notice the startling contrast between the open, sunny environment of the dunes and the lush, shady world of the beech-maple forest. Sugar maples and American beech are the predominant trees, but non-native insects and diseases are having a devastating effect on these forests. Beech bark disease is killing the beach trees, emerald ash borer, the ash trees. Most of these non-native pests are moved into the Lakeshore by hitching a ride on firewood. Help up protect the forest by leaving your firewood at home!