Forest vegetation plays an important role in protecting water quality
The trees and ground vegetation in forest ecosystems slow water movement and help stabilize soil. Prevention or reduction of soil erosion helps reduce sedimentation type pollution in streams, rivers and lakes.
Water pollution is generally classified into one of two very broad areas: point source, pollution that can be traced to a relatively specific point of origin, and non-point source, issues that arise from wide areas, generally from runoff. Types of non-point source pollution would include increased nutrients and sedimentation.
Sedimentation, or soil movement into our waterways, is the leading cause of non-point source pollution nationally. Although some movement of soil as water flows across the ground is going to occur naturally, poorly planned human activities can greatly increase soil erosion. This increased erosion can lead to ever increasing sedimentation in our water resources.
Vegetation helps to slow water movement, reducing soil erosion, which leads to less pollutants getting into our waterways. This valuable assistance is provided in several ways. Raindrops hitting leaves, stems and other plant parts get interrupted and redistributed, thereby reducing the velocity of direct soil impact. Well-established vegetation slows water movement across the soil surface, which both reduces erosion and allows for more of the water to soak in. Lastly, plant roots help hold or lock the ground in place.
Stripping land of vegetation will expose soil and greatly increase the opportunity for soil erosion and stream sedimentation. The steeper the slope of the ground or the more susceptible the soil is to erosion, the greater potential there is for damage. Finer particle clay soil is most easily eroded when bare ground is exposed by these disturbances.
Michigan has established guidelines for maintaining vegetative zones adjacent to waterways to help reduce the chances for erosion to help protect our waterways. The Sustainable Soil and Water quality Practices on Forest Land includes guidelines that recommend that a vegetative buffer strip of at least 100 feet be left intact next to waterways. This strip is more commonly referred to as a riparian management zone (RMZ).
In addition to maintaining forest land vegetation adjacent to open water, there are efforts that individual homeowners can adopt that will help protect water quality. Michigan State University Extension has a tip sheet available to help guide waterfront owners. Maintaining Waterfront Turf to Preserve Water Quality (E0011) provides valuable suggestions that landowners are encouraged to follow to help us all preserve our valuable fresh water resource.
Waterfront owners wanting to use vegetation to stabilize shorelines while keeping things natural can get some suggestions and valuable links to information from the Michigan Natural Shoreline Partnership.