Challenges for the conservation of vanishing megadiverse rupestrian grasslands

Abstract

The Espinhaco Mountains comprise a mountain range that stretches more than 1200 km in the east of South America. In these mountainous environments occur the rupestrian grasslands, a complex mosaic of vegetations influenced primarily by relief and ancient geological history. Far from being homogeneous, rupestrian grasslands show different grassy and shrubby vegetation types on rock outcrops (quartzite, sandstone or ironstone), stony to sandy soils, peat bogs, and other transitional physiognomies such as altitudinal cerrado, gallery forests, remnants and hillside Atlantic Rain Forests (e.g. Medina and Fernandes, 2007; Carvalho et al., 2012). In grassland physiognomies the main factor of environmental stress is greatly associated with sandy-stony soils, often very shallow, with low nutrient levels, extreme aluminum toxicity, and low water holding capacity (Carvalho et al., 2012; Negreiros et al., 2014). High radiation incidence and a long period of annual water deficit (Luttge et al., 2007) confer additional harshness to this singular ecological system. Plants exhibit several types of physiological, biochemical, morphological, structural and phenological adjustments to survive to environmental stresses (Luttge et al., 2007; Negreiros et al., 2009, 2014). Like other ancient ecosystems with extremely