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Harvard Forest Symposium Abstract 2008

• Title: Incorporating landscape-scale edaphic variation into regional ecosystem forecasts using ED2
• Primary Author: Michael Dietze (Harvard University)
• Additional Authors: Paul Moorcroft (Harvard University); Andrew Richardson (Northern Arizona University)
• Abstract:

  Ecologists have long recognized consistent vegetation patterns at the landscape-scale due to edaphic variation in topography, hydrology, and soils. Despite the recognition that different portions of the landscape function differently and may respond differently to climate change (e.g. upslope migration), current regional and global scale vegetation models do no capture this heterogeneity. In general, the scale of variability (10-1000m) is orders of magnitude finer than model grid resolution (0.25-1 degree). We have developed a spatially approach to capturing subgrid spatial heterogeneity that accounts for topographic variability in microclimate, solar radiation, and lateral hydrology. We are validating this model using a combination of data from the the Harvard Forest and Bartlett Experimental Forest eddy-covariance towers (daily-interannual ecosystem fluxes), the Hubbard Brook experimental water sheds (hydrology, multidecadal vegetation dynamics and heterogeneity), and the USFS Forest Inventory and Analysis (regional and edaphic gradients in growth and mortality). We will present results on the model's ability to capture watershed hydrology, ecosystem fluxes, and edaphic gradients in vegetation dynamics. Also, unlike empirical studies where edaphic variables are often highly correlated, the mechanistic modeling approach allows us to estimate the seperate contributions of different edaphic factors. We will present a preliminary partitioning of the effects of microclimate, lateral hydrology, and hillshading on carbon and water flux.

• Research Category: Forest-Atmosphere Exchange
  Large Experiments and Permanent Plot Studies
  Physiological Ecology, Population Dynamics, and Species Interactions
  Regional Studies
  Soil Carbon and Nitrogen Dynamics
  Watershed Ecology