Smith was intrigued by the study because the effect was indirect and cut across ecosystems as traditionally defined. "Ecologists tend to study forests, or ponds, or glades, but there is a lot of border crossing going on," he says, "and Tiffany's study demonstrated that."
His idea was to see if he could find links that went the other way, connecting land to water instead of water to land. If fish affected land plants, could plants affect fish or at any rate aquatic communities?
One plant that might tug hard on ecosystem connections, Smith thought, was the purple loosestrife, which produces many showy flowers and displaces native plants such as cattails that produce few or none.
"The flowers make it functionally different from the native plants," Smith says, "so it seemed possible its presence would cause a disturbance that would ripple through the wetland communities."
But it took a few years for Smith to start the experiment.
"Everybody I talked to about it thought that one of the links would fail; that it wasn't possible for every connection from the plant to the aquatic system to hold as I had hypothesized it would," Smith says. "I sort of felt that way, too. It seemed like a long shot."
Eight artificial wetlands
But the tradition at Tyson Research Center is to challenge fundamental ecological ideas with the methods and tools of science, and so in the summer of 2009, Smith finally undertook what he knew would be a labor-intensive experiment.
He and colleagues Laura A. Burkle, PhD, then a postdoctoral fellow who is now a faculty member at Montana State University, and Joseph R.
|Contact: Diana Lutz|
Washington University in St. Louis