Nature has often been recognized for its glorious beauty and invigorating power by countless artists, poets, and scientists. Now a West Virginia University biologist has the opportunity to explore how one of the Earth's amazing—though unappreciated—powers actually works.
Through a five-year grant funded by the National Science Foundation, Professor Mark Walbridge, chair of the Department of Biology, is examining how a forested floodplain removes phosphate from floodwaters prior to export downstream.
Walbridge explains that natural ecosystems perform fundamental services that are essential for sustaining human life. These ecosystem services arise from complex interactions between natural cycles and ecological processes, and could cost trillions of dollars annually to replace by artificial means.
Increased levels of phosphate, a common pollutant resulting from the development of natural ecosystems for agriculture or human habitation, are dangerous to aquatic ecosystems. A surplus of phosphate promotes an abundant accumulation of nutrients that support a dense growth of algae and other organisms, which in turn decay and deplete the water's oxygen content.
Ecosystems operate like a set of dominoes. When one element of the system is destroyed or altered, the surrounding parts in the system also falter or die. The forested floodplain acts as a natural liquid purification plant that protects downstream environments from harmful chemicals, such as phosphate.
The transformation of phosphate within forested floodplains has been known for more than 30 years, but the details of how this critical ecosystem function is accomplished are poorly understood.
"Because human population growth and consumption cause the continued alteration of natural ecosystems, identifying and monitoring ecosystem services is critical for sound environmental decision making," Walbridge says.
He began working on this project in October 2001, and has established 12 study sites throughout the southeastern United States: one in Virginia, three in Georgia, three in South Carolina, and five in North Carolina.
Each site is located downstream of a U.S. Geological Survey Station, which continuously reports the water level of the river via the world wide web. This way, Walbridge knows when a site has flooded, and thus when to collect data at each site.
Researchers at these sites sample the water coming into the floodplain, then sample the water again as it is leaving the floodplain. Walbridge looks for chemical changes in the water, trying to understand what chemicals and nutrients are retained by the floodplain and/or how harmful chemicals received from input waters are converted to less harmful forms prior to their export downstream.
"Improving our understanding of phosphate retention and transformation mechanisms in floodplain forests will improve our ability to predict both the effects of floodplain forest losses on downstream water quality and ecosystem integrity, as well as the effects of increased phosphate loading on both forested floodplains and downstream aquatic ecosystems," Walbridge says.
Walbridge, who earned his B.A. in 1973
and M.S. in 1982, both from WVU, became interested in forested
floodplains while working on his master's degree, when Biology
Professor Emeritus Charles H. Baer led visits to the Cranesville
Swamp. During Walbridge's postdoctoral years at Duke University,
1985 through 1989, he first worked in southern floodplain systems
near Clarkton, North Carolina. The project involved wastewater
additions to the Brown Marsh Swamp. 