David D. Myrold's research interests are defined by the intersection of forestry, soil science and microbiology. A Presidential Young Investigator award will afford him the chance to pursue these interests with greater freedom during the next five years than might otherwise have been the case. In his previous work, he has found that microbial denitrification (conversion of nitrates to bimolecular nitrogen) capacity is limited largely by the availability of carbon, rather than by availability of nitrates. Use of radiotracers and mathematical modeling of the nitrogen cycle enabled the simultaneous estimation of mineralization, immobilization, nitrification, and denitrification components in the laboratory. Dr. Myrold will continue studies of nitrogen cycling in forest ecosystems and, in addition, will initiate research dealing with actinomycete (Frankia) strains using immunological and genetic techniques, and also the role of microbial biomass as a sink and source of nutrients (mainly nitrogen) in forest systems. The latter studies are especially important with respect to questions that concern the ultimate fate of nutrients in systems subject to forest management practices such as burning and fertilization. Laboratory analyses will be conducted at Oregon State University, while the field portions of research are to be done among the various forest types found in the state of Oregon.
