for National Geographic News
Conservation corridors are a boon for plant diversity, according to a new study that researchers say proves a widely practiced but still controversial theory.
The corridors are narrow strips of land that connect isolated patches of wild habitat, such as nature reserves, often trapped in seas of human developments such as farms and subdivisions.
Many experts say corridors benefit biodiversity by allowing plants and wildlife access to a wider range of resources.
For example, when food and water are scarce in one patch of habitat, they may be abundant in another. Without a corridor connecting the patches, some species would be unable to reach necessary resources.
But other scientists have said that corridors put species that use them at greater risk from dangerssuch as vehicle traffic and pollutantsthat lurk on either side of a narrow passage.
(Related news: "Animal Overpasses, Tunnels Offering Roadkill Remedy" [May 2004].)
Proof that the networks help preserve multiple plants and animals at large scales has remained elusiveuntil now.
A team of scientists led by Ellen Damschen, an ecologist at the University of California, Santa Barbara, carved up a vast swath of a South Carolina pine forest into six 5,382-square-foot (500-square-meter) experimental plots.
Over five years open patches of habitat that were connected to other patches via narrow corridors grew about 20 percent more plant species in each plot than isolated patches did.
"Corridors have a positive impact on the diversity of species," Damschen said.
She and her colleagues report the finding in this week's issue of the journal Science.
Theory in Use
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