Abstract DBI-9804198 Michelle C. Mack This action funds an NSF Postdoctoral Research Fellowship in Biosciences Related to the Environment for 1998. This fellowship provides an opportunity for the Fellow to gain additional scientific training beyond the doctoral degree and to pursue innovative and imaginative research into the fundamental mechanisms underlying the interactions between organisms and their environment at the molecular, cellular, organismal, population, community and/or ecosystem level in any area of biology supported by the Directorate for Biological Sciences of the National Science Foundation. Each fellowship supports a research and training plan to be carried out in a sponsoring laboratory. The research and training plan for this fellowship is entitled effects of mosses on thermal and chemical controls of decomposition in the boreal forest. Most studies that relate plant functional groups to ecosystem processes focus on direct effects, such as the effects of litter quality on decomposition or nitrogen mineralization rates. Plant functional groups can also affect ecosystem processes indirectly through effects on microclimate. Effects of plant species on soil temperature may be particularly important in the high latitude systems that contain a large portion of global terrestrial carbon stores, where below-ground ecosystem processes such as decomposition and nutrient dynamics are often temperature-limited. In boreal forests, mosses can comprise up to 100% cover of the forest floor. This research hypothesizes that mosses are strong thermal regulators in boreal forest ecosystems and thus exert dominating control over ecosystem carbon storage. The goals of the research are to quantify important moss traits for ecosystem energy fluxes; differentiate between moss thermal and chemical effects on decomposition, and link effects to nutrient cycling and carbon storage; and use models to test the role of mosses in ecosystem change following distu rbance and climatic change.
