Tuesday, June 5, 2007 - 10:15 AM
121

Controlling Phragmites australis and the effects on microbial biomass and invertebrate communities

Emmalisa Brown, Laura G. Leff, and Ferenc A. de Szalay. Biological Sciences, Kent State University, Kent, OH 44242

Wetland ecosystem structure and function depend on decaying plant material as sources of energy and carbon. Microbes assimilate this detrital material and serve as a foundation for wetland food web structures.  Invertebrates, in turn, feed on the microbes and transfer carbon and energy to higher trophic levels.  Litter material that is more difficult to breakdown, such as the invasive plant Phragmites australis (Cav) Trin. ex Steud (common reed), may alter the nutritional value of the foundational material.  Eradication of Phragmites and restoration of the community to a non-invaded state has been achieved by cutting and herbicide treatment.  Such methods are effective in reducing stand size of the invasive plant but increase detrital material availability and impact quality. In this study, litter produced from cutting and herbiciding and litter from a native wetland species wool grass Scirpus cyperinus (L.) Kuenth were placed in litter bags below stable water levels in experimental wetlands.  Periodically, samples were removed and mass loss, fungal and bacterial biomass, and invertebrate community composition were examined.  Mass lost was highest for the cut treatment and lowest for S. cyperinus. Microbial biomass differed between treatments and diverse communities of aquatic invertebrates were present on the three treatments.