B33J-05:
Spatially-Explicit Estimates of Greenhouse Gas Emissions from Fire and Land-Use Change in the Brazilian Cerrado
Wednesday, 17 December 2014: 2:40 PM
Gillian L Galford, University of Vermont, Burlington, VT, United States, Stephanie Anne Spera, Brown University, Providence, RI, United States, Michael Thomas Coe, The Woods Hole Research Center, Falmouth, MA, United States and Ciniro Costa Jr., CENA Center for Nuclear Energy in Agriculture, Piracicaba, Brazil
Abstract:
Understanding the multiple types of land-use changes that can occur within an ecosystem provides a comprehensive picture of the human’s impact on natural systems. We use the Cerrado (savanna) of Brazil to examine the primary and secondary impacts of land-use change on greenhouse gas emissions. The primary land-use changes include fires for land-clearing, conversions to pasture and row-crop agriculture, and shifting management practices of agricultural lands. Secondary land-use changes include savanna degradation due to fires that escape from intended burn areas. These escape fires typically have a lower combustion completion coefficient than clearing fires, so it is important to distinguish them to correctly estimate the regional greenhouse gas budget. We have created a first-order spatio-temporal model of greenhouse gas emissions that can be easily modified for other savanna regions using globally available data products as inputs. Our data inputs are derived from publically available remote sensing imagery. Initial biomass is estimated by Baccini et al. 2012, which is derived from LiDAR and MODIS imagery. All other input data sets give annual estimates. Clearing of the savanna is documented by LAPIG of Universidade Federal de Goias using MODIS (MOD13Q1), LANDSAT and CBERS images. MODIS burned area products delineate annual fires; in combination with the savanna clearing database we determine primary and escape fires. Pastures and row-crop agriculture are documented by LAPIG and Spera et al. 2014, respectively. The row-crop agriculture dataset enables us to estimate greenhouse gas emissions associated with specific crops (e.g., soy or maize) and management (e.g., fertilizer use). Recent contributions to the literature have provided many in situ measurements from the land-use changes of interest needed to estimate a regional greenhouse gas budget, including combustion coefficients of savanna sub-types, carbon emission soil stocks, nitrogen emissions from fertilizer, and carbon storage in pastures. With this wealth of information, we present a complete greenhouse gas portfolio including a sensitivity analysis for this dynamic region with an eye to applications for other savanna regions.
