Take a 20-pound bag of mulch, dump it on a table, and sort its contents by size, down to the half millimeter. This is the mind-numbing task of the root sorter. "We know lots about the ecosystem above the ground," says Ruth Yanai, a professor
at the State University of New York College of Environmental Science and Forestry. "But we're just starting to get a sense of the ecosystem underground." Among other things, Yanai studies how long roots live and what effect acid rain has on root growth. To do her research, she needs roots to be sorted by size--and we're not talking inch-large tubers, but tiny tendrils. One of her workers does it eight hours a day. With a pile of roots in front of him, he uses tweezers to put them in size-appropriate piles. One batch of roots takes him two hours, for less money than he'd get busing tables at Denny's.