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Kretchun Master's of Environmental Management Final Presentation

posted May 11, 2012, 2:24 PM by Alec Kretchun   [ updated Aug 18, 2012, 8:05 AM by Robert Scheller ]
MEM student Alec M. Kretchun give his final project presentation, entitled "The effects of multiple disturbances on carbon sequestration in the forests of the New Jersey Pine Barrens under different climate scenarios", on Wednesday, May 16th. You can view a recording of his presentation here


The New Jersey Pine Barrens (NJPB) is a unique forested ecosystem and the largest contiguous forest along the mid-Atlantic seaboard. Recent policy has brought attention to increasing forestland carbon (C) sequestration as a mitigation strategy for abating greenhouse gas emission but this ecosystem service is dependent on these forests continuing to act as a carbon sink. We used LANDIS-II, a spatially explicit forest succession and disturbance model, to model the effects of climate change, gypsy moth defoliation, and wildfire on the forests of the New Jersey Pine Barrens over the next century, paying particular attention to the C dynamics of the system.  Gypsy moth outbreaks were calibrated using USFS Forest Health Monitoring defoliation maps as well as previously employed model parameters for tree species responses. Our results show that climate change affects the magnitude and trajectory of most major C fluxes (ANPP, NEE) more than gypsy moth defoliation or wildfire, the two modeled disturbances. Defoliation did significantly reduce detrital C in the wet lowland and upland forests of the NJBP. Variability in ANPP and NEE was greatly increased with gypsy moth defoliation, but the magnitude of these C fluxes were not significantly altered. Respiration rates showed spikes which were directly associated with defoliation outbreaks. Species composition changes showed an increase in oaks over the course of the 100-year simulation, exacerbating the succesional trend towards oak domination seen in previous research. These results suggest a need for reintroduction of fire on the landscape for both abating pine extirpation as well as managing resident gypsy moth populations.