Land cover mapping of the tropical savanna region in Brazil

Abstract

The Brazilian tropical savanna (Cerrado), encompassing more than 204 million hectares in the central part of the country, is the second richest biome in Brazil in terms of biodiversity and presents high land use pressure. The objective of this study was to map the land cover of the Cerrado biome based on the segmentation and visual interpretation of 170 Landsat Enhanced Thematic Mapper Plus satellite scenes acquired in 2002. The following land cover classes were discriminated: grasslands, shrublands, forestlands, croplands, pasturelands, reforestations, urban areas, and mining areas. The results showed that the remnant natural vegetation is still covering about 61% of the biome, however, on a highly asymmetrical basis. While natural physiognomies comprise 90% of the northern part of the biome, only 15% are left in its southern portions. Shrublands were the dominant natural land cover class, while pasturelands were the dominant land use class in the Cerrado biome. The final Cerrado's land cover map confirmed the intensive land use pressure in this unique biome. This paper also showed that Landsat-like sensors can provide feasible land cover maps of Cerrado, although ancillary data are required to help image interpretation.

Tropical grassy biomes: linking ecology, human use and conservation

“…Increasing land-use intensity and fragmentation disrupts disturbance regimes and vegetation dynamics [72], potentially amplifying a global change-induced trend of encroachment by further reducing tree mortality. To date, 50% of the Brazilian cerrado has been transformed for agriculture, a rate of land-use change roughly double that of the Amazon forest [73,74]. Land has historically been perceived as being of marginal agricultural value across TGBs [10,58].…”

Remote sensing for biodiversity monitoring: a review of methods for biodiversity indicator extraction and assessment of progress towards international targets

“…Landsat data, including the Multispectral Scanner (MSS), Thematic Mapper (TM), and Enhanced Thematic Mapper Plus (ETM+) sensors, are effective sources for terrestrial mapping, including habitat classification (Boyd et al 2006;Bock et al 2005), LC mapping of tropical areas (Paneque-Gálvez et al 2013), savannas (Sano et al 2010), grasslands (Price et al 2002), or forests (Jiang et al 2004;Wijedasa et al 2012), and change detection (Demir et al 2013;Berberoglu and Akin 2009). Other optical data include: the similar spatial resolution (i) Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) (Reiche et al 2012;Lucas et al 2011) and (ii) Linear Imaging Self Scanning Sensor 3 (LISS-III) (Lucas et al 2011); the higher resolution (iii) Advanced Visible and Near Infrared Radiometer type 2 (AVNIR-2) (Vaglio Laurin et al 2013) and (iv) High Resolution Geometric (HRG) instrument (Lucas et al 2011); and the very high resolution (VHR) (v) QuickBird and (vi) WorldView-2 (Petrou et al 2014;Adamo et al 2014) sensors.…”

Woody encroachment and its consequences on hydrological processes in the savannah

“…This barrier has been surpassed in the last decades by technological advances, resulting in a rapid land conversion and certainly huge biodiversity losses [45,46]. Land conversion for pasture, agriculture or forestry, the most common land uses in the Cerrado biome [45], has probably influenced many ecological processes, among which are those related to water resources. Distinct land uses can have opposite influences on hydrological processes, such as annual river discharge increasing after forest conversion for agriculture or pasture [47,48] or decreasing after afforestation [13,49].…”