Teaching Interests

Ecosystem Ecology
Microbial Ecology
Wetland Ecology
Mycology

Research Interests

Through my research I seek to expand our knowledge of detrital processing and biogeochemical cycles in ecosystems. Specifically, I am interested in the functional role of fungal organisms in these processes. Despite the wealth of qualitative evidence indicating fungal colonization of plant detritus, very little research has examined the quantitative impacts of fungal organisms on biogeochemical cycles at the ecosystem scale, or their potential contribution to total ecosystem metabolism. In the past, my students and I have focused on quantifying the ecosystem-level role of bacteria and fungi in the breakdown and mineralization of both standing and collapsed litter of wetland emergent macrophytes, such as Typha, Juncus and Phragmites. More recently, my interests have expanded to include a variety of questions relating to large-scale impacts (e.g., increasing atmospheric CO2, invasive species, eutrophication) and potential microbial interactions on bacterial and fungal processes in wetlands as well as other environments.

A recently funded (USDA) collaboration with terrestrial ecologists Drs. Robert Mitchell (Jones Ecological Research Center) and Joseph Hendricks (University of West Georgia) is focusing on belowground carbon allocation in southern longleaf pine forest ecosystems. A shortcoming of many root production studies is that mycorrhizal fungi have not been included as a component influencing belowground net primary production despite being widely recognized as a potentially large component of belowground carbon allocation in terrestrial ecosystems. This research project will examine the relationships among stored carbon and current photosynthate on belowground carbon sinks, such as fine root and ectomycorrhizal fungal biomass and production, root respiration, and soil respiration.

Representative Publications

Gulis, V., K.A. Kuehn and K. Suberkropp. (2006) The role of fungi in carbon and nitrogen cycles in freshwater ecosystems. pp. 404-435, In: G.M. Gadd (ed), The Role and Impact of Fungi on Biogeochemical Cycles. Cambridge University Press, Oxford, United Kingdom.

Sims, S.E., J.J. Hendricks, R.J. Mitchell, K.A. Kuehn and S.D. Pecot. (2007) Nitrogen decreases and precipitation increases ectomycorrhizal extramatrical mycelia production in a longleaf Pine forest. Mycorrhiza 17:299-309.

Su, R., R.N. Lohner, K.A. Kuehn, R. Sinsabaugh and R.K. Neely. (2007) Microbial dynamics associated with decomposing Typha angustifolia litter in two contrasting Lake Erie coastal wetlands. Aquatic Microbial Ecology 46:295-307.

Rier, S.T., K.A. Kuehn, and S.N. Francoeur. (2007) Enzymatic response of stream microbial communities colonizing inert and organic substrata to photosynthetically active radiation. Journal of the North American Benthological Society 26:439-449.

Francoeur, S.N. A.C. Johnson, K.A. Kuehn, and R.K. Neely. (2007) Evaluation of the efficacy of the photosystem II inhibitor DCMU in periphyton and its effects on non-target microorganisms and extracellular enzymatic reactions. Journal of the North American Benthological Society 26:633-641.  

Gessner, M.O., V. Gulis, K.A. Kuehn, E. Chauvet and K. Suberkropp. (2007). Fungal decomposers of plant litter in aquatic habitats. Pages 301-324. In: C.P. Kubicek and I.S. Druzhinina (eds), The Mycota Vol. IV., 2nd edition: Environmental and Microbial Relationships, Springer Verlag, Germany.

Gulis V., K.A. Kuehn, and K. Suberkropp. (2008) Fungi. In: G.E. Likens (ed) Encyclopedia of Inland Waters, Elsevier Ltd., Oxford (in press).

Kuehn, K.A. (2008) The role of fungi in the decomposition of emergent wetland plants. In: K.R. Sridhar and F. Bärlocher (eds), Novel Techniques and Ideas in Mycology, Fungal Diversity Press, Hong Kong (in
press).