Study Shows Forestry Best Management Practices Prevent Erosion

Jefferson City, MO - infoZine - Tuttle is forestry field programs supervisor for the Missouri Department of Conservation. Gwaze is a resource scientist for the agency. Both were concerned about criticisms of timber harvesting on conservation areas.

“There was a time when our critics examined our timber-sale sites and criticized us, and we probably deserved it,” said Tuttle. “It’s not surprising that people are suspicious of logging. Historically, Missouri has mined the forest resource real hard.”

By “mining,” Tuttle means logging with no thought for the future of the forests, wildlife, streams or anything except immediate profits. Recovering from the brand of cut-and-run logging and abusive farming practices in the late 19th and early 20th centuries took decades in the steep hills of the Ozarks. Streams there still are lined with gravel that washed off denuded hillsides with soil during generations of land abuse. When the Conservation Department acquired some of that abused land, it worked to restore and maintain healthy forests, streams, fish and wildlife.

The science of forestry was still in its infancy when Conservation Department stewardship began. Developing sustainable forest management practices involved years of trial and error along with scientific research. By the late 20th century, foresters around the nation were compiling their accumulated knowledge of forest management in books of “best management practices,” or BMPs.

“We got our book the same way other states did,” said Tuttle. “We started with our own, and then we looked at what other states were doing and said ‘Oh, this looks good, let’s put that in our book.’ So then we had this BMP book, and it looked really good on paper. But people were still telling us that our timber sales caused erosion. We said, ‘Let’s see if we have erosion, and if we do, let’s change our BMPs.’”

To determine how effective Missouri’s forestry BMPs were, the Conservation Department enlisted the help of John Bowders, a professor of civil and environmental engineering at the University of Missouri. Together, they designed a seven-year study to determine how clear-cuts on conservation areas affected water quality in adjacent wet-weather streams.


The study involved four master’s degree candidates and two PhD students. They focused mainly on the amount of sediment entering streams. However, they also studied 11 other measures of water quality, including the amount of nitrogen and phosphorus compounds that was washing into streams.

They worked on 15 study sites on Angeline and Current River conservation areas. Five of the sites served as controls, where no timber harvest occurred. On the other 10, loggers conducted regeneration harvests, commonly called clearcuts. Researchers sampled water captured as it ran down hillsides and also in streams.