LTREB: Forest Ecosystem Response to Changes in Atmospheric Chemistry and Climate at the Bear Brook Watershed in Maine (BBWM)

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0210257FernandezThe Bear Brook Watershed in Maine (BBWM) is a long-term paired, forested watershed researchsite with each watershed drained by a first order stream through a v-notch weir. One watershed(West Bear) has been treated bimonthly for 12 years with N and S by aerial helicopterapplications, with the second watershed (East Bear) serving as the reference watershed. Theobjectives of this LTREB proposal are to:1. Study the response of the calibrated East Bear Watershed to long-term patterns of ambient S,N, and base cation deposition. This will be accomplished by maintaining high qualitydeposition and stream export data from the reference watershed in support of research onecosystem processes and change over time funded by this project and others.2. Study the temporal progression of N saturation at the West Bear Watershed. This will beaccomplished by continuing the decadal-scale whole ecosystem N & S addition experimentongoing at the West Bear Watershed. 3. Determine if a definable relationship exists between short and longer-term climate and thebiogeochemical and hydrologic processes currently under study at both watersheds. Thiswill be accomplished by establishing an air and soil temperature measurement program across major ecosystem compartments at BBWM. Studies will focus on the relationships between temperature, N dynamics (mineralization, nitrification), and surface water N export in both the reference and treated watersheds, and we will evaluate the efficacy of using heat units to predict ecosystem behavior with respect to these processes.4. Provide support to strengthen the data management efforts at the BBWM, thereby makingthis long-term record more accessible to the scientific community with an interpretiveinterface to be used by educators and policy makers through an expansive web presence. Amajor emphasis of this LTREB proposal is the development of a layered web presence on theBBWM project that provides access to data and highlights for policy makers, educators andresearchers.5. Provide support for graduate student training and undergraduate student experiences inresearch.Findings from this research have proven to be turnkey to date in regional and national debates onthe effects of acid deposition and the risk of N saturation to forests and surface waters of NewEngland. The compelling justification for supporting the long-term program of research atBBWM is that changes in response to changing ambient deposition of N and S (East Bear), long-term chemical manipulations (West Bear), and seasonal and inter-annual climate variation after11+ years are showing mechanisms of response that were not discernable within the first 2-3years of the study. These long-term mechanisms of response are frequently overlooked whenresearch is conducted on short-term funding cycles. The long-term and unique responses beinginvestigated at BBWM will be critical for adequately assessing policy and management optionsregarding air pollution and climate change in the 21 st century.