Researchers examine role of soil patterns in dam r...( MADISON Looking at the site today it...)

MADISON Looking at the site today, it's easy to forget that a dam and pond stood for 43 years on the University of Wisconsin-Madison's Franbrook Farm Research Station in southwestern Wisconsin. All traces of the structure are gone, and acres of plants, both native and weedy, now carpet the floor of the former basin.

Nevertheless, memories of the dam remain, and by digging into the soils of the basin, UW-Madison researchers are now unearthing them. Writing in a special issue (December) of Restoration Ecology, they report the discovery of two superimposed patterns of soil properties that chronicle distinct stages in the basin's history: its decades of submersion, and its emptying when the dam was breached and removed.

"In our analysis, we were able to pick up those different soil patterns, which was pretty exciting," says soil science professor Nick Balster, who led the study with doctoral candidate Ana Wells and landscape architecture professor John Harrington. "We could see the chemical and physical patterns that were created both by the inundation (of the land) and by the draining."

Fascinating as those traces of the past are, however, what they mean for the future is the real question, Balster says. After seeding the basin with prairie species, the scientists are now waiting to see if the soil patterns affect the growth and distribution of the plants, and their ability to stand up against weedy, invasive competitors.

"By doing this research, we're asking the question, 'How much do soils matter in the restoration of these basins?'" Balster says. "As people who love to study soil we're going to say, 'A lot! Soils likely drive the whole thing.' But as scientists, we don't know yet."

Answering that question is becoming more and more pressing. During the past three decades, hundreds of dams nationwide have reached the end of their lives, forcing dam owners to make costly repairs or increasingly to remove the
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