Ice Caves No Longer Safe
The ice formations in Leelanau Township, north of the park, are no longer safe to visit. High winds have fractured the ice, moving it to the west. Huge cracks have formed in the cave arches, making them very unsafe and open water is now visible.
Consider the conditions that plants must deal with on the dunes; strong sunlight; low soil fertility; drying wind action; limited soil moisture; wind erosion, which can expose root systems; and build-ups of sand which can partially or completely bury plants.
Notice the cottonwood trees growing on the steep dune across the road. They are managing to survive despite their precarious position. The cottonwood is the only common tree of the dunes, and is well adapted to the dune environment. Its fast rate of growth allows it to keep pace with burial by sand. Notice that the trees are growing in a cluster. This too is typical. The cottonwood can 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. This helps to stabilize 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.
Did You Know?
You will find a wide variety of camping and backpacking options at Sleeping Bear Dunes National Lakeshore - from electrical hook-ups and modern bathrooms to wilderness backpacking. More...