Linking Isolated Habitats Said to Help Biodiversity Around the world, once-giant ecosystems have been cut up into tiny fragments. Islands of habitat have been left on the land that can be wiped by a single storm. For years, ecologists have said that fragments of this kind do better when they're reconnected by thin corridors.

    Environment Story Of The Day NPR hide caption

    toggle caption

Linking Isolated Habitats Said to Help Biodiversity

  • Download
  • <iframe src="" width="100%" height="290" frameborder="0" scrolling="no" title="NPR embedded audio player">
  • Transcript


Around the world, once giant forests have been sliced and diced by loggers, farmers, and developers. What remains are disconnected forest fragments that can harbor lots of rare species. To help these plants and animals survive, biologists and governments have spent billions reconnecting the forest fragments, usually with narrow corridors of trees. For years, this work has been essentially an act of scientific faith since there's been little proof that these corridors preserve rare species. Now there is, according to a study in the journal Science.

NPR's John Nielsen has more.

JOHN NIELSEN: Once upon a time, a forest straight out of a fairytale stretched from Virginia to Texas. Giant, long leaf pine trees formed an open canopy above a wide array of animals and an even wider range of plants. Botanist Ellen Damschen says one of her favorites was a flower called lupin, which has a special way of spreading seeds.

Ms. ELLEN DAMSCHEN (Botanist, National Center for Ecological Analysis): Capsules that explode, and literally their seeds go flying when the pod is released.

NIELSEN: Damschen was also partial to the aster plants that had pretty, yellow flowers stuck to six-foot tall stems.

Ms. DAMSCHEN: So as you're walking through the forests you can actually have plants that are taller than you are with these bright, yellow flowers.

NIELSEN: Ninety percent of those amazing forests are gone now, Damschen says. Plants like the lupin and the aster remain, but many are trapped inside the disconnected forest fragments, tiny islands sitting in a sea made up of suburbs, farms and tree plantations.

Ms. DAMSCHEN: And so the question then becomes what can we do using conservation tools to preserve the biodiversity that we do have in habitats that remain?

NIELSEN: Ecologists have long assumed the answer to that question is a fairly simple one: build forest corridors that help plants and animals in healthy forest fragments re-colonize the damaged ones. Damschen says studies have shown that corridors help animals known to ecologists as charismatic mega vertebrates.

Ms. DAMSCHEN: Like tigers, or bears, or wolves.

NIELSEN: What hasn't been clear is whether these corridors help the less well known species, especially the ones that can't pull up their roots and go for walks - plants like lupin and aster.

Damschen, who works for the National Center for Ecological Analysis in Santa Barbara, has been trying to figure out whether corridors can help save rare plants since the 1990s. That's when she started studying experimental corridors created by the U.S. Forest Service in South Carolina. For years, she walked five miles a day in hot, sticky weather looking for evidence that rare plant species were indeed spreading through corridors. What she found essentially is that they were and much more quickly than expected.

This was true in part because the bees and bugs that pollinate these plants were traveling down the corridors with them. Damschen's colleagues found a clever way to track the movements of these bees and bugs: sprinkling fake pollen that glowed in the dark on the tops of certain flowers.

Ms. DAMSCHEN: They sort of used the fluorescent dye powder, and they would go out at night with a black light and determine if the pollen had been moved.

NIELSEN: The lines of glowing specks seemed to march down the corridors were visible proof that the plants were using them. Now, Damschen will admit that chasing plants isn't quite as sexy as tracking tigers. But in the long run, her team's work could prove invaluable, especially to the people who are now designing corridors. One reason why is that those big, fierce animals might not survive if the plants and bugs stay put, so says Taylor Ricketts, director of conservation science at the World Wildlife Fund.

Mr. TAYLOR RICKETTS (Director of Conservation Science, World Wildfire Fund): It's not just an interesting thing to understand scientifically, but it's going to, in the long run, inform a lot of conservation and restoration policy.

NIELSEN: Damschen is continuing her corridor work at the South Carolina field site. But now she's looking for answers to some more problematic questions, such as whether corridors help spread diseases.

John Nielsen, NPR News, Washington.

Copyright © 2006 NPR. All rights reserved. Visit our website terms of use and permissions pages at for further information.

NPR transcripts are created on a rush deadline by an NPR contractor. This text may not be in its final form and may be updated or revised in the future. Accuracy and availability may vary. The authoritative record of NPR’s programming is the audio record.