Constraining Centennial-Scale Ecosystem-Climate Interactions with a Pre-colonial Forest Reconstruction across the Upper Midwest and Northeastern United States

Tuesday, 16 December 2014: 5:30 PM
Jaclyn Hatala Matthes1, Michael Dietze2, Andrew M Fox3, Simon J Goring4, Jason S McLachlan5, David J Moore6, Benjamin Poulter7, Tristan L Quaife8, Kevin M Schaefer9, Joerg Steinkamp10 and John W Williams4, (1)Dartmouth College, Dept. Geography and Grad Program in Ecology & Evolutionary Biology, Hanover, NH, United States, (2)Boston University, Boston, MA, United States, (3)NEON, Boulder, CO, United States, (4)University of Wisconsin, Madison, WI, United States, (5)University of Notre Dame, Notre Dame, IN, United States, (6)University of Arizona, Tucson, AZ, United States, (7)Montana State University, Bozeman, MT, United States, (8)University of Reading, Reading, United Kingdom, (9)University of Colorado, National Snow and Ice Data Center, Boulder, CO, United States, (10)Senckenberg, Frankfurt, Germany
Interactions between ecological systems and the atmosphere are the result of dynamic processes with system memories that persist from seconds to centuries. Adequately capturing long-term biosphere-atmosphere exchange within earth system models (ESMs) requires an accurate representation of changes in plant functional types (PFTs) through time and space, particularly at timescales associated with ecological succession. However, most model parameterization and development has occurred using datasets than span less than a decade. We tested the ability of ESMs to capture the ecological dynamics observed in paleoecological and historical data spanning the last millennium. Focusing on an area from the Upper Midwest to New England, we examined differences in the magnitude and spatial pattern of PFT distributions and ecotones between historic datasets and the CMIP5 inter-comparison project’s large-scale ESMs. We then conducted a 1000-year model inter-comparison using six state-of-the-art biosphere models at sites that bridged regional temperature and precipitation gradients. The distribution of ecosystem characteristics in modeled climate space reveals widely disparate relationships between modeled climate and vegetation that led to large differences in long-term biosphere-atmosphere fluxes for this region. Model simulations revealed that both the interaction between climate and vegetation and the representation of ecosystem dynamics within models were important controls on biosphere-atmosphere exchange.