HILO, HAWAII--Corridors that connect fragments of habitat can benefit a variety of plants and animals, according to research reported here on 1 August at the Society for Conservation Biology meeting. It's the first study to look at whether organisms as disparate as butterflies, birds, plants, and rodents can all use the same, lone path between two pieces of suitable habitat.
Maintaining narrow strips of habitat between larger fragments has been suggested for years as a way to help plants and animals survive in landscapes riven by human activity. Over the past decade, many scientists have studied the benefits of such corridors for a single species (ScienceNOW, 27 March) or, at most, several closely related species.
The Savannah River Corridor Project in South Carolina goes farther. Researchers there have built a series of experimental patches linked with corridors by clear-cutting 27, 1.5-hectare squares in the midst of a pine plantation. ("Clear-cut" in this case creates useful habitat for plants and animals that don't do well in the pine fields.) Some of the clear-cut patches are linked by corridors from 64 to 384 meters long; other patches are isolated.
The researchers, led by ecologist Nick Haddad of North Carolina State University in Raleigh found more movement between connected patches than between unconnected patches for two species of butterflies, three species of bird-dispersed plants, old-field mice, and several bee and wasp species. For example, twice as many seeds from the bird-dispersed plants showed up in the connected patches compared with the unconnected patch, and old-field mouse traffic was 5 times greater between connected patches than unconnected patches. Of the more than 10 taxa studied, only cotton rats seemed to move through the landscape with no regard for the presence or absence of corridors.
It's an important study, says conservation biologist Reed Noss of Conservation Science Inc. in Corvallis, Oregon. "They have looked at responses of a number of different species in the same landscape--and that I've not seen done."