There are several common plant communities, or associations, which vary in structure and characteristic species. The forests of the region are adapted to the strong seasonal variation in rainfall, including wet-season flooding and dry-season fires. Many trees are deciduous, losing their leaves during the winter dry season, Deciduousness is more common in the semi-arid south. The
soto/ association includes the trees soto (
Schinopsis brasiliensis), curupaú (
Anadenanthera macrocarpa), momoqui (
Caesalpinia pluviosa), morado (
Machaerium scleroxylon), roble (
Amburana cearensis), and cedro (
Cedrela fissilis). This association is found on well-drained soils. Trees form a canopy averaging 20 meters in height with emergent trees up to 30 meters. The canopy is 80% closed, and there is an understory of shrubs and herbs. In the
cuchi/ association, either curupaú (
Anadenanthera macrocarpa) or cuchi (
Astronium urundeuva) predominates. It grows on well-drained but nutrient-poor soils, including rocky mountain slopes and sandy lowland soils. The canopy varies from 10 to 15 meters in height and is 65% closed, with emergent trees up to 25 meters high. The
cuta/ajo-ajo association is predominantly cuta (
Phyllostylon rhamnoides) and ajo-ajo (
Gallesia integrifolia). This association is found on seasonally-flooded soils near streams. The
tajibo/ association is of Tajibo (
Tabebuia heptaphylla) and (
Machaerium hirtum). It forms patches of forest on low rises (half a meter to a meter) surrounded by open savanna. The ecoregion also has areas of grassy savanna similar to the
Cerrado savannas further east. ==Fauna==