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New Hybrid Estimate of Tropical Deforestation Rates in the 1980s and 1990s

Holly Gibbs, University of Wisconsin-Madison, hkgibbs@wisc.edu (Presenting)
Jonathan Foley, University of Wisconsin-Madison, jfoley@wisc.edu
Navin Ramankutty, McGill University, navin.ramankutty@mcgill.ca
Ruth DeFries, University of Maryland, rdefries@mail.umd.edu
Frédéric Achard, Joint Research Center, frederic.achard@jrc.it

Tropical land cover dynamics during the 1980s and 1990s are highly uncertain, with enormous implications for balancing the global carbon budget and understanding the impacts on ecosystem goods and services. Recent estimates of tropical deforestation vary by +/-40% due in part to differences in domain, forest baselines, methods, and definitions. The 8km AVHRR satellite record provides the only spatially-explicit data, with comprehensive global coverage, for both the 1980s and 1990s. However, sensor calibration and degradation issues combined with the coarse spatial resolution of AVHRR data mask more diffuse deforestation events and likely capture only net changes in forest cover, thereby underestimating both gross deforestation and forest regrowth. Higher resolution Landsat data can capture gross changes in forest cover but the processed data products are currently limited to particular regions or sampling schemes and “wall-to-wall” coverage is not available for the total tropics during the 1980s and 1990s. We are using ~600 manually classified Landsat scenes from the TREES project and the FAO’s Forest Resources Assessment to develop spatially-explicit regression models based on demographic, biophysical, and land-use predictor variables. We are using the regression models to create an improved spatially-explicit estimate of tropical deforestation rates and locations that incorporates the strengths of key regional and global-scale data sets.

Science Theme:  LC (Land Use and Land Cover Change)

Presentation Type:  Poster

Abstract ID: 49

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