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Harvard Forest Symposium Abstract 2010

  • Title: Non-linear terrestrial ecosystem responses to meteorological variability
  • Primary Author: David Medvigy (Harvard University)
  • Additional Authors: Paul Moorcroft (Harvard University); J. William Munger (Harvard University); Steven Wofsy (Harvard University)
  • Abstract:

    Terrestrial ecosystem models are essential tools for assessing the impact of climate change on vegetation. To assess the response of ecosystem structure and function to changes in the environment, models are driven by environmental variables such as solar radiation, temperature, and precipitation typically derived from general circulation models or reanalysis products. The higher-order statistics of these drivers, e.g., temporal variances and covariances, have not been perceived as critical, and consequently have received little attention. Here we show that high frequency variances of meteorological drivers have powerful ecological consequences. Short-term variability of sunlight and precipitation systematically lower Net Ecosystem Productivity; incorrect specification of temporal variability may thus lead to large systematic errors in rates of forest growth and long term ecosystem structure, even though daily, weekly or monthly means are realistic. In northeastern forests, for example, growth of conifers is more strongly affected than hardwoods, causing major shifts in forest composition on decadal time scales in response to changes in hourly variability. We conclude that the high frequency variances of meteorological drivers are critical elements for climate-ecosystem studies.

  • Research Category: Ecological Informatics and Modelling, Forest-Atmosphere Exchange