Biophysical properties of cultivated pastures in the brazilian savanna biome: An analysis in the spatial-temporal domains based on ground and satellite data

Abstract

Brazil has the largest commercial beef cattle herd in the world, with cattle ranching being particularly prominent in the 200-million ha, Brazilian neotropical moist savanna biome, known as Cerrado, one of the world's hotspots for biodiversity conservation. As decreasing productivity is a major concern affecting the Cerrado pasturelands, evaluation of pasture conditions through the determination of biophysical parameters is instrumental for more effective management practices and herd occupation strategies. Within this context, the primary goal of this study was the regional assessment of pasture biophysical properties, through the scaling of wet- and dry-season ground truth data (total biomass, green biomass, and % green cover) via the combined use of high (Landsat-TM) and moderate (MODIS) spatial resolution vegetation index images. Based on the high correlation found between NDVI (normalized difference vegetation index) and % green cover (r = 0.95), monthly MODIS-based % green cover images were derived for the 2009-2010 hydrological cycle, which were able to capture major regional patterns and differences in pasture biophysical responses, including the increasing greenness values towards the southern portions of the biome, due to both local conditions (e.g., more fertile soils) and management practices. These results corroborate the development of biophysically-based landscape degradation indices, in support of improved land use governance and natural area conservation in the Cerrado. © 2013 by the authors.