9806493 Harmon Leaf and root decomposition can be thought of as a continuous process beginning with fresh plant litter and leading to the fomation of increasingly refractory organic matter. This refractory material is thought to be a precursor to soil organic matter, and thus influences nutrient availability, production, and carbon sequestration in ecosystems. A team, LIDET (Long-term Intersite Decomposition Experiment Team), has installed a set of experiments to test the effects of macroclimate and substrate quality on the long-term carbon and nutrient dynamics of leaf and fine root litter. These long-term experiments involve 16 LTER and 11 other cooperating sites, and a total of 31 types of litter. The experiments are designed to follow changes in mass, organic fractions, and nutrients for up to 10 years. Now that the study as passed its half-way point, continued funding will allow the completion of data collection, laboratory analysis of organic constituents, and nutrient content. In addition, data will be made available over the Internet. The plan is to continue the original design and to add a new study on the chemistry of native litters at each site. This new work will provide a litter chemistry data set that is compatible with the LIDET decomposition data and will also allow broad-scale extrapolation of the substrate quality findings of the experiment. The data generated by this study will prove extremely useful in future modeling and synthesis efforts. This funding will also provide the investigators the time and money to complete this long-term intersite project.
