Results from a four-year study to two chronic N-limited forests ecosystems at the Harvard Forest have shown rapid changes in CH4 consumption, and the initiation of pulse losses of N20. These have occurred in synchrony with changes in N03, leaching losses, N03 and NH4 concentrations in soils, C02 efflux, and foliar nitrogen chemistry. In this study, the principal investigators will measure C0 consumption in these same systems, which they hypothesize will respond analogously to CH4 consumption. The combined changes influxes of CH4, C0) and N20 they expect to elicit, if representative of regional-scale responses to chronic N deposition, would contribute significantly to altered atmospheric chemistry and global climate. The PI's are well qualified to conduct this research and the facilities are excellent.
