For years, ecologists have theorized that establishing landscape corridors to connect otherwise isolated plant and animal habitats would encourage biological diversity. Now researchers working in South Carolina have demonstrated it, at least with plants.

The researchers, who report their findings in the current issue of the journal Science, surveyed dozens of test plots in forested areas of the Savannah River Site, a 310-square-mile swath of southeastern South Carolina originally set aside to produce nuclear weapons for the military. (The plots are now managed by the federal Forest Service for pine production.)

The researchers surveyed their sites regularly starting in 2000 and found that, over time, there was more plant diversity in patches connected by corridors than in other patches, even if they had the same total area or the same amount of “edge” space between cleared and wooded areas.

Patches connected by landscape corridors “had 20 percent more species of plants than unconnected patches,” said Ellen Damschen, the lead author of the report and a postdoctoral fellow at the University of California, Santa Barbara.