Advances in the Remote Sensing of Terrestrial Vegetation and the Development of a Predictive Science of the Biosphere

Paul R. Moorcroft, Harvard University, paul_moorcroft@harvard.edu (Presenter)

Remote sensing measurements of terrestrial vegetation have been integral to the development of earth system models. This interplay began with the use measurements of the fraction of absorbed photosynthetically active radiation (FPAR) and leaf area index (LAI) in terrestrial biosphere models such as the Simple Biosphere Model (versions 1 and 2) that were used to provide lower boundary conditions for atmospheric general circulation models (GCMs). To this day, remote sensing measurements of albedo, and leaf area index remain vital global sources of information for constraining and evaluating the biophysics and photosynthesis parameterizations of terrestrial biosphere models. The interplay between terrestrial biosphere models and remote sensing measurements has, however, now entered a new more complex and challenging era because most modern-day terrestrial biosphere models now also integrate their predictions of short-term (hourly-interannual) carbon, water and energy fluxes into corresponding predictions of long-term (decadal-to-century scale) changes in above- and belowground ecosystem structure and composition. As yet, these predictions regarding the long-term, large-scale dynamics of terrestrial ecosystems are, however, largely untested. Consequently, uncertainty regarding the long-term response of the terrestrial ecosystems to increasing atmospheric carbon dioxide and accompanying changes in climate forcing has ballooned: due the biogeochemical feedback between gains and losses of carbon within terrestrial ecosystems and atmospheric carbon dioxide concentrations, terrestrial biosphere models are now the second largest source of uncertainty regarding the amount of the climate change expected to occur over the coming century. New remote sensing measurements, such as lidar and radar measurements of vegetation structure, remote sensing derived time-series of global disturbance dynamics, and imaging spectrometry measurements of plant canopy composition, promise to provide important and much-needed constraints for evaluating and improving terrestrial biosphere model predictions of how the earth’s terrestrial ecosystems will change over the coming century.

Presentation: 2015_Apr20_AM_Moorcroft_18.pdf (6296k)

Presentation Type:  Plenary Talk

Session:  Theme 1: Tracking habitat change through new integrative approaches and products

Presentation Time:  Mon 11:06 AM  (18 minutes)