In their work to restore Indiana prairies, Deborah Marr (in the white hat) and Andrew Schnable (holding the transect tape), both assistant professors of biological sciences at IU South Bend, have studied plant diversity in general, but also have focused in more detail on white wild indigo (Baptisia leucantha). Jessica Perkey and Stuart Orr, undergraduates at IUSB, are shown here helping to collect data on white wild indigo, which can be recognized by the tall white flower heads, at one of the native prairie sites in northern Indiana. Deborah Marr and Andrew Schnable have been impressed, not to mention highly encouraged, with the speedy increase in bird, amphibian, reptile and insect diversity in the restoration areas.

Marr and Schnable presented a paper on their work at the Indiana Academy of Science meeting Oct. 16-17.

“More than 90 percent of the prairie, wetland and savanna communities that were present in Indiana in the early 1800s have been converted into cropland, industry and business sites, and housing developments,” said Marr. “Currently, there are tiny fragments of these remnant communities standing along railroad right-of-ways, in nature preserves that are 30 acres or less in size or on privately owned land. Some of these remaining fragmented communities have an extraordinary number of plant and animal species, but many of these species are in decline because the populations are too small.”

The Nature Conservancy’s goal in the Efroymson Kankakee Restoration project is to establish viable plant and animal communities that will connect existing nature preserves, Marr said. Connecting preserve areas will provide a larger network of suitable habitat for animals and plants and should help existing remnants persist over longer periods of time.

Marr said that so far, there are encouraging signs, though restoration efforts are only about five years old.

For example, Marr and Schnable compared plant species diversity in three restored tall-grass prairie sites with three nearby remnant prairies to monitor the success of the restorations from 2001-2003. The restored areas they surveyed were planted in 1997, 1998 and 1999. According to Marr, based upon all species sampled, the older two restorations were similar to the values for the remnant sites analyzed in 2001 and 2002 surveys. The youngest restoration, however, was less diverse than remnant sites.

Also, while all of the restored sites currently have a lower proportion of native species and a higher ratio of grasses to forbs (herbs) compared to remnant prairie communities, native plant species diversity and abundance in restored sites did increase between 2001 and 2002. In contrast, one remnant site showed little change in plant species composition across years.

“Our studies of the plant communities provide information on how closely the restored prairies mimic native prairies,” said Marr. “We are looking at not only plant species composition, but also how seed production, levels of insect and deer feeding on plants, and genetic diversity of selected plant species compare between restored and native prairies. Our findings so far show that as restorations age, they are becoming more similar to native prairies in species diversity.

“In the first three years of planting a restoration, we see a plant community that begins with a high proportion of weedy non-native species, and within a few years, becomes dominated by native vegetation,” Marr said. “In contrast, the change from one year to the next in native prairies has been relatively small. The similarity among native prairies in ratio of grasses to forbs also has been most interesting. Each of the native prairies is quite different in terms of the plant species present, types of soil and site history, yet at this broad level of organization, there tends to be 55 percent forbs and 45 percent grasses present.”

Marr and Schnable also have been impressed, not to mention highly encouraged, with the equally speedy increase in bird, amphibian, reptile and insect diversity in the restoration areas. In one area, said Marr, Wilson’s phalarope, a bird that was thought locally extinct in Indiana, nested for the first time in 2002. All of this would indicate that as native habitats are restored, some species will be able to re-establish themselves.

“The landscape of the Midwest includes many different ecosystems or habitats that form a continuum from wetlands to prairie to savanna to forest,” said Marr. “All of these habitats are needed, not only to support a wide diversity of species, but also to help preserve water quality and limit soil erosion.

“Once a habitat has been destroyed it cannot be replaced,” she continued. “There is so much that we don’t know about how soil microbes, such as mycorrhizal fungi, aid in establishment of plant communities and how plant community composition affects severity of feeding damage from insects. But I am encouraged.

“I think our first approach must be to preserve remnant areas whenever possible. But this restoration project has demonstrated the potential for helping small remnant areas to persist long term and also suggests we think more holistically about links between habitats.”