Measuring whether the right mix of bacteria is returning to a restored wetland can be a valuable biological indicator scientists can use to evaluate restoration success, he added.
"We found that one of the simplest and most promising indicators of restoration success was the ratio of Proteobacteria, which have the highest affinity for nutrient-rich environments, to Acidobacteria, which have the highest tolerance for poor conditions," Hartman said.
The researchers determined soil bacterial composition and diversity within restored wetlands, agricultural fields and undisturbed wetlands across North Carolina's coastal plain. They sampled these paired land-use categories across three distinct types of wetlands: pocosin bogs, floodplain swamps and backwater swamps that were not connected to streams.
Samples were also taken from sections of the Everglades, the largest wetland in the United States, where a $10.9 billion effort is now underway to remediate the effects of agricultural runoff.
"We identified bacterial groups by their evolutionary relationships, which were determined by sequencing DNA extracted from soils," Hartman said. "This approach allowed us to capture a much greater diversity of bacteria than would be possible using conventional laboratory culturing, which works for only a small fraction of the 10,000 to 1 million species of bacteria that can be found in a single cubic centimeter of soil."
Previously, researchers have used genetic techniques to target known organisms or bacterial groups in wetland soils, he said. "But this study is unique in that we used these methods to capture the full range of bacterial groups present, and determine how their composition shifts with land-use changes and restoration."
"These types of findings can only be obtained in studies done on sites that have been restored and studied over a number of years and assessed with these modern techniques," Ric
|Contact: Tim Lucas|