03/18/2010 05:12 am ET Updated May 25, 2011

Botanists Debate the Benefits of Assisted Plant Migration

We recognize that climate change is likely to be very rapid and that seeds only disperse a few hundred yards, half a mile at most, naturally, said Kayri Havens, the botanic garden's director of plant science and conservation. "They'll need our help if we want to keep those species alive."

Other scientists argue that tinkering with the complexity of habitats is courting disaster -- and huge expense.