Biodiversity and conservation of the Cerrado: recent advances and old challenges

Excerpt

Covering about 2 Mio. km² by the arrival of the first European settlers, the Cerrado savannas are second in extent only to Amazonian forests amongst the South American biomes (Diniz et al. 2010; Eiten 1972; Oliveira and Marquis 2002). The Cerrado sits strategically at the centre of the continent, connecting two open vegetation biomes—the Chaco to the southwest and the Caatinga to the northeast—thus forming a diagonal corridor of dry habitats in South America, and simultaneously establishing a biogeographical barrier between two forest biomes—Amazonia to the northwest and the Atlantic Forest to the southeast (Schmidt and Inger 1951; Vanzolini 1963; Werneck 2011). Moreover, it also occurs as isolated patches within other biomes, presumably relicts of a more extensive past distribution (Barbosa et al. 2007; Carneiro Filho 1993; Cole 1960; Pennington et al. 2000). The relief consists of ancient, extensive plateaus dissected by younger valleys, carved by some of the major drainages of South America, i.e., Paraná-Paraguay, Tocantins-Araguaia, São Francisco and Parnaíba (Albert and Reis 2011; Braun 1970; King 1956; Mittermeier et al. 2000). The climate is of the Aw type in Köppen’s classification, distinguished by marked and highly predictable seasonality, dry winters, and annual precipitation ranging from 1300 to 2300 mm (Alvares et al. 2013; Nimer 1989). Soils are old, acidic, nutrient-poor, with high levels of Al and Fe, and strongly influenced by the water regime (Lopes and Cox 1977; Motta et al. 2002; Vendrame et al. 2013). A complex topography and a dynamic geological history created the highly heterogeneous Cerrado landscape (Furley 1999; Sano et al. 2019), with a pronounced horizontal compartmentalization of the biota into three major habitat types—grasslands, savannas, and forests—determined by local topography, soils and water availability (Colli et al. 2002; Furley 1999; Nogueira et al. 2005; Oliveira-Filho and Ratter 2002; Ribeiro and Walter 1998). As in other tropical savannas, fires are frequent and most species have adaptations for survival under a regime of periodic burns (Costa et al. 2013; Frost 1985; Hoffmann 2002; Miranda et al. 2009; Mistry 1998; Salgado-Labouriau and Ferraz-Vicentini 1994). The origins of the Cerrado biota date from the Late Cretaceous, presumably evolving from pre-savanna ecosystems between 145 and 65 mya (Aguiar et al. 2020; Colli 2005; Ratter et al. 1997; Romero 1993), although the current biotic configuration has been established much more recently (Simon et al. 2009). …