• Trees provide natural environmentally friendly erosion control along stream banks.river bank image by PeteG from Fotolia.com
  
  The Iowa Department of Natural Resources has long recognized the benefits of using trees to combat erosion along many of the state's rivers and streams. Besides firmly anchoring the soil with their roots, trees keep stream waters cooler which benefits many native fish species. Furthermore, trees beautify the landscape and provide homes and food for many other species of wildlife. The department has published a list of the tree varieties best suited for erosion control in Iowa.
  
  

Black Locust

• Among the trees the Iowa Department of Natural Resources recommends for erosion control is black locust (Robinia pseuodoacacia). The trees grow rapidly and will thrive in the sandy soils often found on stream banks. A mature locust will eventually reach a height of 80 feet. Their fragrant blossoms are a nectar source for wild honey bees. Because the trees are armored with sharp thorns, they also provide predator-proof nesting sites for many species of native songbirds.
  
  

Common Chokecherry

• Another desirable erosion control tree is the common chokecherry (Prunus virginiana). Classified as either a woody shrub or a small tree, they will eventually reach a height of about 20 feet. As its name implies, the tree produces crops of fruit which mature in mid-summer. A favored food source for many wild birds, the fruit can also be used to make preserves and syrups. Chokecherry trees grow rapidly and will occasionally form dense thickets.
  
  

Swamp White Oak

• Another species which prefers keeping its feet wet is the swamp white oak (Quercus bicolor). If allowed to grow to maturity, a swamp white oak will eventually attain a height of 60 to 70 feet. Their species name refers to the fact that their leaves are green on top, and whitish on the underside. They also produce abundant crops of acorns which are a food source for deer, squirrels and wild turkeys.
  
  

Eastern Cottonwood

• Because it grows rapidly and is well adapted to damp soils, eastern cottonwood (Populus deltoides) is another recommended erosion control plant. The eastern cotton is a large tree which will eventually develop a massive trunk over 6 feet in diameter. A mature specimen may reach a height of 100 feet. Also referred to as Carolina poplar, the trees grow as much as 5 feet in a single growing season. Sadly, eastern cottonwoods have a short lifespan.
  
  

Green Ash

• Systematic and planned erosion control projects are collectively referred to as bioengineering. The green ash (Fraxinus pennsylvanica) is another species often planted for this purpose. It is the most widespread native ash with a range which extends from the Atlantic coast to the foothills of the Rockies. The trees prefer growing in the moisture-rich alluvial soils found along rivers and stream banks, making them ideal for controlling erosion.