This time of year it’s great to work outside, clean up the place and mow. But if you’re lucky enough to have a stream on your property, think again before clearing that tangle of brush and trees. You’re looking at something good.
Brush and debris are dirty words to many people, who think it’s a mess, a problem. They prefer the “estate” look, with tall trees, groomed green grass, water with nothing in it but water. They chop or spray or clear everything else.
But if you know what brush is — how rich and diverse it is, how valuable — it’s beautiful. To the stream it is life-saving.
Recent research shows that if a stream looks “cleaned up” to the human eye, it’s a disaster for the stream and everything in it. A stream needs a natural mix of shrubs, a layering of foliage and root systems, and leaf litter and woody debris in the water to stay healthy and thrive.
The worst thing for a stream is chopped brush, a cleared bank, a mowed floodplain. That’s a bare-naked stream. Unnatural.
It’s well known how trees and shrubs hold stream banks in place with their roots, how vegetation holds back sediment. But trees and shrubs do more than that. The tangle, the overhanging branches and leaves, literally feed the river.
Study in recent decades by the Stroud Water Research Center in Avondale, Pa., in conjunction with U.S. Forest Service scientists, has revolutionized our understanding of streams, especially forested headwaters. Their research led to the River Continuum Concept, which shows how microbes and aquatic invertebrates brew fallen leaves and other organic matter into an energy-rich “watershed tea” that nourishes everything downstream, including parts of rivers too wide to have leaves overhead.
In America east of the Plains, before trees were cleared, upland streams always flowed through forests. Floodplains were forests. That was their natural state.
We need to protect our small upper streams that remain natural and preserve their natural function.
Mowing lawns to the water’s edge, chopping brush from the banks, pulling out woody debris from the water — all these can starve a stream.
“Brush” isn’t one thing at all, but hundreds of species of native plants — wild cranberry, prickly ash, nannyberry, red-twig dogwood, hornbeam, greenbrier, witch hazel. These shrubs, as well as large trees like sycamore and cottonwood, thrive in the moist soils of stream banks and floodplains.
Grass alone isn’t good enough. Its roots are shallow and don’t hold soil in a flood.
So instead of mowing or clearing the edge of a stream, let the brush tangle. Let it lean and dip. Let leaves fall into the water. Maybe clip a walking path so you can wind your way through the pawpaws or wingstem for a natural view of the water.
When you know how rivers and natural streams work, you see them differently. Instead of a tangle of brush to chop or remove, you’ll see roots holding soil, a cooling canopy. Instead of seeing woody debris in the water as a mess or a problem, you’ll see organic material that feeds fish and everything downstream as well.
You’ll see new views, new beauty — purple nannyberry seeds, the golf ball-size blooms of carrion flower and the weird sci-fi flowers, like computerized explosions, of buttonbush. You’ll protect your own stream banks, your neighbor’s water and the river downstream. “Brush” is good for a stream, and it’s great for the Great Lakes, for the Gulf of Mexico, for the life of all our rivers.
JANET KAUFFMAN has restored wetlands on her farm in Hudson, Mich., and works with the Bean/Tiffin Watershed Coalition. Her most recent book is “Trespassing: Dirt Stories & Field Notes,” a half-story, half-essay examination of industrial livestock operations. She wrote this comment for the Land Institute’s Prairie Writers Circle, Salina, Kan.