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Dr. Anthony Yannarell, a new Assistant Professor at NRES, is using his research to help the U.S. Army fight invasive weeds. Many people do not know this, but military bases in the U.S. are often home to a number of different threatened and endangered species. The U.S. Army Corps of Engineers is serious about protecting the habitats that these organisms depend upon. These protected areas at some military installations throughout the southern and western U.S. are being taken over by large populations of an introduced plant, Lespedeza cuneata, or Chinese Lespedeza (photo below). |
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In collaboration with the Army Corps' Construction Engineering Research Center (CERL) and the Illinois Natural History Survey, Dr. Yannarell is investigating how soil microorganisms are helping Chinese Lespedeza spread into protected areas of military installations at the expense of threatened and endangered plant species.
Chinese Lespedeza is a member of the pea family (Fabaceae) and was first introduced to the southern United States for erosion control and as a forage item for wildlife. However, the traits that make it drought hardy and useful for soil stabilization have also allowed it spread to many habitats that managers never intended, and now it readily invades open woodlands, meadows, fields, wetlands, and disturbed areas. In these new habitats, it can establish very thick stands and crowd out native plants.
Relationships with microorganisms are key to the success of Chinese Lespedeza. Like other members of the Fabaceae, Lespedeza forms close associations with soil bacteria that can feed the plant with nitrogen derived from the atmosphere. Also, Lespedeza can form relationships with special kinds of soil fungi, called mycorrhizal fungi, that can help the plant's roots scavenge moisture and nutrients from the surrounding soil. These microbial relationships may help give the plant a leg up against its competitors. Dr. Yannarell's research is aimed at learning more about these relationships: which soil microbes are involved, how they operate, and how they help Chinese Lespedeza expand into new habitats and displace native species.
With CERL's help, Dr. Yannarell's research group will examine soil samples from 5 different military bases from around the Southern and Midwestern U.S. The soil samples have been collected from the roots of Chinese Lespedeza and some of its native competitors. Dr. Yannarell's lab will use molecular biology techniques to examine microbial genes from these soils to understand how the Chinese Lespedeza has changed the microbial communities of soil to be more favorable to itself and less favorable to its competitors. This will lead to a deeper understanding of how belowground microbial communities can shape aboveground plant communities and play a major role in plant invasions.
