Living landmarks grace the shore

Living landmarks grace the shore. . , The large cottonwood trees you see across the river are about 80 years old. They're reminders of a floodplain forest that once stretched from Minnesota to Louisiana. Cottonwoods share river floodplains with many other tree species that have adapted to the rigors of high and low water., cottonwood , (Populus deltoides), American elm , (Ulmus americana), black ash , (Fraxinus pennsylvanica), black willow , (Salix nigra), silver maple , (Acer saccharinum), Why Here? , Floodplains follow our national river, Follow the Mississippi River from the Crow River near Dayton and Ramsey downstream to Hastings and experience a special place on Earth. These 72 miles of bluff, river, and floodplain forest have been designated as the Mississippi National River and Recreation Area, a unit of the National Park Service., Riverbanks and cottonwood, a stable relationship, The cottonwood's abundant cottony seeds, making the ground appear snow-covered in summer, sprout best on moist gravel beds and sandbars that hug the shore. Once the trees have grown, the tough and expansive root systems of mature cottonwoods help hold fragile riverbanks in place., What is a floodplain?, A floodplain is the flat land next to a river that is covered with deposits of river sediment., When more water enters a river than its channel can carry, the muddy, sediment-rich river rises and spills over its banks., As the floodwaters spread out over the land, they slow down, and some of the sand, silt, and clay they are carrying settles out., Living on the edge, Trees living on the floodplain must survive the perils of high water and pummeling by ice, logs, and other debris carried in seasonal floodwaters., Many trees die in these floods, clearing space in the forest where new trees can sprout., Those trees that remain face less competition for sunlight and water and can rapidly grow to great size.