"I know this sounds counterintuitive but it's true. City-grown pollution -- and ozone in particular -- is tougher on country trees," says Jillian W. Gregg, lead author of the Nature cover article, "Urbanization effects on tree growth in the vicinity of New York City." Other authors of the Nature report are Clive G. Jones, an ecologist at the Institute of Ecosystem Studies in Millbrook, N.Y., where some of the field studies were conducted, and Todd E. Dawson, professor of integrative biology at the University of California, Berkeley, and a professor at Cornell when the study began.
Gregg was a Cornell graduate student, pursuing a Ph.D. in ecology, when she started planting identical clones of cottonwood trees (also known as poplars, or by the scientific name Populus deltoides ) in and around New York City. Test sites included the New York Botanical Garden and the Hunts Point water works in the Bronx; a Consolidated Edison fuel depot in Astoria, Queens; as well as Long Island's Brookhaven National Laboratory in Upton; Eisenhower Park in Hempstead; and the Cornell Horticultural Research Laboratory in Riverhead. About 50 miles north of Manhattan, in the Hudson River valley, she also planted cottonwood clones at the Millbrook institute.
One aim of the study was to show the impact on plants of a tough life in the city, where a variety of gaseous, particulate and photochemical pollutants from fossil-fuel combustion bombard plants as they struggle to grow in heavy metal-laden soils. The fast-growing poplars were to serve as a kind of "phytometer" to gauge the
Contact: Roger Segelken
Cornell University News Service