With patience, Emily Cruz detangled a vine with Dorito-shaped leaves from a fallen branch, unwinding it slowly and then pulling it out from the roots.



The 12-year-old and 40 other middle-school girls were working to remove what’s known as mile-a-minute vines recently from New York City’s largest green space as part of a program aimed at encouraging girls to pursue environmental science. Over the years, the fast-growing plant has elbowed its way into Pelham Bay Park in the Bronx, which is more than three times the size of Manhattan’s Central Park.

“Invasive means they’re not from here,” Emily explained, still concentrated on the thorny plant as bugs buzzed around her. “We’re getting rid of them because they wrap around young trees and make it hard for them to grow and reach the light.”

Emily and the other girls were observing the plants with Green Girls, which is run by the City Parks Foundation. It’s expanded from a three-week summer program to a five-week course that runs year-round since it started in 2002. While the summer program investigates urban forests, the focus is on drinking water during the school year. The key to its success, program leaders say, is the confidence the in-the-field activities give the girls. At a time when environmental professionals complain of a "leaky pipeline," Green Girls aims to plug the holes.