Gene Likens and his research team first discovered acid rain more than 30 years ago. Now, they would like to discover a way to ameliorate the damage to the environment caused by industrial air emissions and other factors.

Likens, the world's leading ecosystem ecologist, spoke at the Thomas J. Dodd Research Center December 7 in the third leg of the Edwin Way Teale Lecture Series. He recounted how his discovery was made and what political actions have since been taken to prevent acid rain.

Likens' initial discoveries of acid rain damage to Hubbard Brook in the White Mountains of New Hampshire in the 1960s have led to a 50-year study of the area, measuring the long-term changes in soil chemistry, tree growth, and stream water biology.

Results from a study conducted by Likens showed 10 to 20 times more acidity in the rain of eastern North America than in remote sites of the world, such as the southern tip of Chile. The northeastern United States is primarily where acid rain is deposited due to weather patterns that carry sulfur from utility plants in the Midwest.

Likens's work brought him to the White House in 1983, where he briefed then-President Ronald Reagan on the problems of acid rain. The meeting led to further follow-up studies and, in 1990, the Clean Air Act was signed into law by President George Bush in an attempt to reduce emissions by 10 million tons every year.

Likens says the individual nature of lakes and streams prevent uniform improvement of pH (acid) levels. Rather, environmentalists and policy makers must concentrate on a "balancing act" of helping some become healthier, even as other lakes and streams may worsen.

Today, the amount of sulfur released by industrial emissions has been successfully reduced, but the forests of Hubbard Brook have stopped growing. Likens hopes that adding calcium to the soil, which acts as a neutralizer, or a "Tums" of the forest, can counteract the acidity. The "Tums" of the forests can be replenished by adding wollastonite, a source of calcium that can be mined in the Adirondacks, says Likens.

"Only if we know the speech of hills and rivers" can solutions be found for the complexities of ecosystem ecology, says Likens, borrowing a quotation from father of environmentalism, Aldo Leopold. .

Likens, a long-time member of the National Academy of Sciences and the American Academy of Arts and Sciences, holds eight honorary degrees, has authored or co-authored 13 books, and has published more than 350 articles.

Marisha Chinski