The Amazon Forest occupies the North Area of Brazil, embracing about 47% of the national territory. It is the largest forest formation on the planet, and is conditioned by the humid equatorial climate. This area possesses a great variety of vegetable physiognomies, from dense forests to open fields. Dense forests are represented by forests of firm earth, the várzea forests which are periodically flooded, and the igapó forests which are permanently flooded as happens in almost the entire central region of Amazônia. The fields of Roraima consist of poor soils in the northern end of the basin of Rio Branco. The campinaranas consists of sandy soils, being spread in "stains" along Rio Negro's basin. These last two formations consist of the Cerrado type of vegetation, thus being areas of cerrado isolated of the main Cerrado ecosystem of the Brazilian central plateau.
The Semi-arid "Caatinga"
This area of uncertain rainfall embraces all the states of the Brazilian Northeast, in addition to the north of Minas Gerais, occupying about 11% of the national territory. Its interior, the Sertão of northeastern Brazil, is characterized by the occurrence of the very thin vegetation of the Semi-arid Caatinga. The highest areas, which are subjected to less intense droughts, are located closer to the coast - they are called Agreste. The transition area between Caatinga and Amazônia is known as Middle-north or Zona dos Cocais (Palm zone). A great expanse of the Interior region of northeastern Brazil suffers a high risk of desertification, due to the degradation of the vegetal covering and of the soil.
The Cerrado occupies the area of the Brazilian Central Plateau. The continuous area of the Cerrado corresponds to about 22% of the national territory, and there are great stains of this physiognomy in Amazônia and some smaller ones in the Caatinga and also in the Atlantic forest. Its climate is particularly remarkable, presenting two very different and well defined aspects. The Cerrado presents varied physiognomies, from clear fields lacking woody vegetation to "cerradões", which are dense arboreal formations. This area is permeated by ciliary forests and pathways that follow the courses of water.
The Atlantic forest
The Atlantic forest, includes the semi-caducifolius seasonal forests, originally, it was the forest of larger latitudinal extension of the planet, ranging from south latitudes of 6 to 32 degrees. The forest once covered about 11% of the national territory, but today its extension is smaller, due to the centuries of deforestation. Nowadays the Atlantic forest only possess 4% of the original extension (the area of Atlantic forest in the above map is the original area - nowdays only scarce stains of forest do exist). It exhibits great climatic variability throughout its distribution, going from temperate, super humid climates in the extreme south, to tropical humid and semi-arid in the northeast. The uneven relief of the coastal zone adds still more variability to this ecosystem. In the valleys the trees are generally well developed, forming a dense forest. On the slopes this forest is less dense, due to the frequent fall of trees. On the tops of the hills generally appear areas of Campos Rupestres. In the south extreme the Atlantic forest gradually mixes with the forest of Araucarias.
The Pantanal Mato-Grossense (Swampland of Mato-Grosso)
The Pantanal Mato-Grossense is the largest plain of continuous flood on the planet, covered by mainly open vegetation that occupies 1,8% of the national territory. This ecosystem is largely formed by sandy lands , covered with different physiognomies due to the variety of micro-reliefs and regimens of flood. As an area transitional between Cerrado and Amazônia, the Pantanal shows off a mosaic of terrestrial ecosystems mostly with the likeness of the Cerrado.
The Fields of the South (Pampas)
In the temperate climate of the extreme south of the country the fields of the south or pampas occur, which represent 2,4% of the vegetal covering of the country. The open lands of the plains and plateaus gaúchos (native of Rio Grande do Sul) and the coxilhas, of soft-wavy relief, are colonized by field pioneer species that form a vegetation type of open savanna. There are areas of seasonal forests and of fields of grassy-woody covering.
The Forest of Araucarias (Area of pines)
In the Brazilian Southern Plateau, with altitudes in excess of 500m, is the area of distribution for the pinheiro (pine tree) do Paraná, Araucaria angustifolia, that occupies about 2,6% of the national territory. In these forests, representatives of the tropical and temperate flora of Brazil coexist, being dominated, however, by the pinheiro-do-Paraná. The forests vary in arboreal density and height of the vegetation and can be classified according to the soil aspects, as alluvial, along the rivers, sub-mountainous, that no longer exist, and mountainous, the major one dominating the landscape. The open vegetation of the gramíneo-woody fields occurs on shallow soils. Due to its high economic value the Forest of Araucaria is suffering from intense deforesting pressure.
Coastal and insular ecosystems
The coastal ecosystems are generally associated with the Atlantic forest due to its proximity. In the sandy soils of the coastal cords and dunes, the sandbanks are developed. They vary in form from low-bushy to arboreal. The manguezais (mangrove lands) and the saline fields of origin fluvial-marine are developed on saline soils. In the sandy or muddy plain land of the Continental Platform the benthic ecosystems occur. In the tidal zone the beaches and rocks, colonized by algae, stand out. The islands and reefs are remarkable geographical features of the superficial landscape.