Not just another pretty place: Pecatonica River provides scientific basis for future restoration projects
Environmental groups annually spend upwards of $1 billion on projects aimed at restoring streams and former wetland ecosystems to their native states.
Yet, there is little solid science to guide these efforts, says Steven Loheide, a University of Wisconsin-Madison assistant professor of civil and environmental engineering. “I see this as an opportunity that we’re missing out on,” he says.
In part, the challenge is that restoration science is a multidisciplinary field still in its relative infancy and practitioners base their choices on intuition. “We want to develop a scientific basis for restoration, rather than just re-create what we think the pristine site used to look like, and hope the function will follow,” says Loheide.
A hydroecologist, Loheide draws on knowledge of engineering, water science and ecology to study stream restoration. To support his research, the National Science Foundation awarded Loheide its prestigious Faculty Early Career Development (CAREER) award.
With the award, Loheide and graduate students Eric Booth and Arlen Striegl are developing and implementing a new technology for monitoring soil moisture. They also are creating a modeling framework through which they can study groundwater and soil moisture changes and how they relate to vegetation composition and patterns. “We would like to be able to improve the practice of restoration by allowing people who are designing restoration projects to be able to predict what the hydrologic change will be and how that will affect the distribution of vegetation across the flood plain,” says Loheide.
He and the students have a living laboratory. For the past three years, they have studied a restored site along the East Branch Pecatonica River in southwestern Wisconsin. Located in the state’s unglaciated region, the site experienced drastic ecological changes from centuries of farming and grazing, erosion in the uplands, and “cultural sediment” buildup in the stream valleys.
The researchers collected data at the site for a year before its restoration in 2008 and now are continuing to gather post-restoration information about groundwater levels, water flow in the stream channel, soil moisture, meteorological conditions, and vegetation composition and distribution.
Already, some evidence shows that plants in the restored site depend less on groundwater level and more on soil moisture around their roots. It’s a distinction that could further define the types of vegetation that would thrive in a particular restoration site.
Loheide’s new technology will enable him and his students to more thoroughly explore the role of soil moisture in restoration outcomes. The researchers will bury a fiber-optic cable across the Pecatonica restoration site. The cable will act as a distributed sensor, enabling them to monitor soil temperature at discrete intervals along its length. Dissipation of heat pulses delivered along the cable will help them quantify soil moisture at those locations. (Dry soil is a poor heat conductor, so heat builds up near the cable and cools slowly.)
The data would inform the researchers’ models, which Loheide anticipates will generate a set of best restoration practices. He hopes his collaborators at the Wisconsin Department of Natural Resources, which restored the Pecatonica site, and The Nature Conservancy in Wisconsin, the landowner, will adopt those practices.
Loheide also hopes to introduce students of all ages to restoration research. Working with Badger Ridge Middle School, he plans to offer field trips to the Pecatonica site. Not only does he hope to teach the students about the science and engineering behind the initiative, but he also aims to show students aspects of science that happen in the field. At the undergrad level, Loheide will integrate restoration practice into his hydroscience course, in which students learn the basics of hydrology and water-resource engineering. Graduate students in his hydroecology course will combine field work with data sets to identify knowledge gaps they can address as a group. “Restoration work is a landscape-scale experiment,” says Loheide. “And from that, we can learn the improve sciences of hydrology and ecology, and ultimately develop better designs for future ecological restoration. The demand for scientific restoration knowledge is way in front of the supply — a situation we hope to change.”
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