Natural Buffers Alder, maples, willows, and many other plants stabilize the stream banks and prevent erosion from storms and snow melt. Their leaves intercept much of the rain before it reaches the ground, returning it to the atmosphere as water vapor. Storm water runoff carrying potential natural pollutants such as silt, nitrogen, and phosphorus, is absorbed and used by the plants before it enters the stream. Soils also store excess water underground, releasing it slowly over time to prevent downstream flooding. Pesticides and other human-generated pollutants may be retained by the soils long enough for bacteria to break them down into harmless compounds.
Birds build their nests in trees along the bank from mud and twigs gathered along the shore.
They feed on the seeds and berries of streamside shrubs or on aquatic insects. Deer and moose come to the stream to drink. In winter, they travel its frozen corridors to their feeding grounds and yard in its sheltered valley. Weasels, mink, skunks, and mice scurry beneath the shade of the streamside forest to avoid the notice of owls, hawks, and other sharp-eyed predators. Night-prowling raccoons leave tiny leprechaun footprints in the muddy banks as they hunt for crayfish and freshwater mussels.