By Susan Milius
A popular tree grows twice as well in the New York metropolitan sprawl as in rural New York State, according to a new test.
![](https://i0.wp.com/www.sciencenews.org/wp-content/uploads/2003/07/3103.jpg?resize=150%2C81&ssl=1)
Clones of an Eastern cottonwood (Populus deltoides) in the Bronx and other city spots grew to double the biomass of clones planted outside small towns upstate or on Long Island, says Jillian Gregg, now of the Environmental Protection Agency’s western-ecology division in Corvallis, Ore.