Iowa has among the highest road density nationwide and, in a conservation twist, this may actually benefit some kinds of wildlife. The state has lost more than 99% of its tallgrass prairie, and restoring prairie along roadsides may help butterflies, according to new research in the April issue of Conservation Biology.
This is the first study showing that restoring native habitat along roadsides can benefit wildlife.
"Our data offer some preliminary evidence that restored roadsides may be able to link habitat," say Leslie Ries, who did this work while at Iowa State University in Ames and is now at Northern Arizona University in Flagstaff, and her two co-authors.
Conservationists have suggested that restoring native plants along roadsides could both connect habitat fragments and increase the overall amount of habitat. Roadsides comprise about 20 million acres of land in the U.S. and many kinds of animals -- including insects, amphibians, birds and small mammals -- use roadside vegetation as habitat.
While Iowa's roadsides have traditionally been monocultures of non-native grasses, some counties in the state have begun reintroducing native prairie plants. Many of these plants provide nectar for adult butterflies and food for caterpillars. Nearly half of Iowa's 44 at-risk butterflies depend on prairies.
To determine how restoring prairie along roads affects butterflies, Ries and her colleagues compared the abundance and diversity of butterflies in 12 prairie roadside areas (4 native and 8 restored) and 12 nearby roadsides that were dominated by weeds or non-native grasses. All the roadsides were bordered by row crops. The butterflies were
The researchers found that prairie roadsides benefitted the
regal fritillary and other butterflies that were more
sensitive to habitat disturbance such as row-cropping and
urban development. These "habitat-sensitive" butterflies were
both more diverse and more abundant alon
Contact: Leslie Ries
Society for Conservation Biology