Scientists begin study of effects of suburbia

Defining 'suburbia' has proved to be challenging.
Knight Ridder Newspapers
SAN JOSE, Calif. -- Suburbia may be familiar turf, but it's one of the last frontiers for scientists trying to understand how ecosystems work and how people are changing the natural world.
From the woodsy suburban enclaves of Vermont to sprawling Chico, Livermore and Gilroy, researchers are starting to probe the role of lawns in global warming, how garden fertilizers and pesticides affect wildlife and how storm water running from roofs, roads and driveways undermines the health of streams.
"The suburban landscape is large, and it's growing," said Jennifer Jenkins of the University of Vermont, one of the scientists who reported her findings last month at a meeting of the American Geophysical Union in San Francisco. "There's this enormous land surface that's falling through the cracks."
Jenkins is involved in a study of 40 suburban yards near Baltimore. Researchers will clip plots of lawn by hand, weigh the clippings, measure the grass stubble and thatch and even rake up leaves for analysis.
The goal is to see how much carbon dioxide the lawns absorb and give off, and whether they're contributing to global warming or slowing it down.
Others are trying to figure out how to design suburban neighborhoods that do less damage to their surroundings.
"We're trying to think about ways to use ecological engineering, green engineering approaches, to solve the problem at its source," said Breck Bowden, also of the University of Vermont.
From a scientific standpoint, it's hard to even define what suburbia is. It slowly grades from sprawling tract housing on the fringes of cities to homes on half-acre lots to the "exurbs" or "ruburbs" -- scattered homes on mostly rural land.
Ecologists have cut their teeth on studies of forests and bogs, deserts and tundra and rain forest, but only recently did they turn to suburbia. Maybe that's because people-dominated landscapes are so complicated and always changing, Jenkins said; maybe they're just less exotic places to work.
Carbon stored in trees
But the 'burbs have a big impact. For instance, of all the carbon stored in trees in Maryland, only about two-thirds is in forests; the rest is in trees planted in yards and median strips, Jenkins found in an earlier study.
That impact is bound to grow. Suburbs are among the fastest-growing land covers in the United States and in the world, said Daniel Bain of the U.S. Geological Survey in Menlo Park, Calif.
One of the first things that happens when people develop farm fields or wild lands is that they pave over parts of it. A study last year found that more than 43,000 square miles of the United States is paved or built upon, an area roughly the size of Ohio.
As a result, rainwater that once would have trickled through the soil gets into streams a lot faster, Bain said. The rushing water scours the banks, cutting the streams deeper and sweeping away habitats for plants, animals and bugs.