Occupying an area of 8,5 km2 and situated in a tropical region, Brazil has a diversity of environments, the product of geological history and recent human influence. These environments correspond, in principle, to the phytogeographic provinces described in the beginning of the 19th century by Carl F.P.von Martius, a botanist who also initiated the monumental “Flora Brasilienses”. Despite having suffered alterations by human action, the standards are still accepted today, when modern techniques of remote sensoring monitor the Brazilian physical environment.
Brazil’s botanical regions were called after the names which the indigenous, the Portuguese, and the first naturalists attributed to them. The Amazon Forest – the “Hiléia” of German naturalist von Humbolt, covers the states of Pará, Amazonas, Amapá, Acre, Rondônia and Roraima, and is also present in the neighbouring countries of Guyana, Surinam, Venezuela, Ecuador, Peru and Bolivia. In Brazil it occupies approximately 3,5 million km2.
The Amazon basin is formed by large rivers of muddy, black or clear waters. Known for holding the largest bio-diversity in the world, the Amazon Forest is basically formed by “matas de terra firme” (dry land forests), which are out of the direct influence of the rivers, not suffering floods; “matas de várzea” (meadow forests), flooded by the muddy rivers in the rainy season; and the “matas de igapó” (igapó forests), almost permanently flooded by black rivers. There are patches of “cerrado” (savanna land) among the forests, as well as poor vegetation and grasslands over the sand patches.
There are thousands of endemic species of fish in the Amazon basin which contribute to the reproduction of riverside plants. The Amazonian endemism is known worldwide, being specially rich in primates, birds, butterflies, fish and other animals. Among others, stand out the “sagui-leãozinho” (a sagoin), the smallest primate in the world, the “preguiça real” (a sloth), the black agouti, the pacarana, the “peixe-boi” (cow-fish), the pink “boto” dolphin, the “uirapuru real” (a song bird of the family Pipriade) and the “galo-da-serra” (Rupicola rupicola).
The Amazon constitutes around 40% of the Brazilian territory. The colonisation process of this vast region needs an adequate policy of sustainable handling, which includes avoiding one of its great and current problems, the burnings. Currently under constant vigilance and monitored daily, they are one of the problems resulting from the colonisation process of the southern part of the Amazon, and from the need for the establishment of a land occupation policy.
To follow, we have the “cerrados”, woodland savannas which have once occupied 25% of the Brazilian territory, in the western portion of central Brazil, and in part of the states of São Paulo, Paraná, Maranhão and Piauí. The “cerrado” appears in areas of deep soil, little stratified, leached and poor in organic matter, a kind of latosolic soil. A dry season of three to seven months leaves marks in the region, causing the disappearance of the herbaceous vegetation, and the scrub trees to loose their leaves. One of the “cerrado” trees, the “ipê” (Tabebuia ochracea) has been declared the symbol tree of Brazil.
The “cerrado” rivers don’t normally dry up, thus maintaining bordering woods called “mata ciliar”. The subterranean water table is 15-20 metres deep, sometimes more. Nowadays the “cerrado” is being used for soya cultivation very successfully, after the improvement of its chemical conditions. Being an open region, it has a typical fauna of herbivorous mammals, ground birds and many reptiles. The handling of the “cerrado” includes the use of fire, and the vegetation is adapted to its passage. In a well preserved “cerrado”, the trees reach a height of 8 to 10 meters. Around 2 million km2 of the Brazilian territory are occupied by “cerrados”. Because of the subterranean system of its vegetation, the “cerrado” is rapidly restored after the frequent burnings.
Set between the “cerrado” and the Bolivian “chaco” (eastern lowlands) is the “Pantanal” (swamplands), formed by the flooding of the rivers of the Paraguay basin, one of the areas of highest tourist potential in Brazil and the largest flooded area in the world. It occupies a large area, with around 150 thousand Km2, mainly in the state of South Mato Grosso. Very rich populations of fish, birds and mammals characterise the “Pantanal”: “tuiuiús” (wood ibis), emus, capybaras, “ariranhas” (Brazilian otters), jaguars etc. The reptiles include alligators (“jacaré”) and anacondas (“sucuri”).
The “caatinga” or the Brazilian “sertão” (bush) is a semi-arid region, very dry, including parts of the states of Bahia, Alagoas, Sergipe, Pernambuco, Paraíba, Rio Grande do Norte, Ceará, Piauí and Maranhão, and occupying an area of around 700 hundred thousand Km2. The annual rainfall regime in the “caatinga” is unpredictable. Therefore it is a region very well adapted to life in low humidity conditions, with a typical xerophytic vegetation. The “caatinga” has undergone great devastation in the past, due to, among other reasons, the use of wood as fuel and the lack of replanting. The soil is often shallow and very rocky.
The environment with the largest biological diversity in Brazil is the Atlantic Forest (“Mata Atlântica”). It is also the one under the biggest threat. Occupying today around five percent of its original area, estimated at 1,5 million km2, it follows the Brazilian coastline closely, from Rio Grande do Norte to the start of Rio Grande do Sul. It was the first environment to be used by the Portuguese colonisers. The name of the country, Brazil, comes from a tree, the pau-brasil (brazil-wood), explored by the indigenous and the colonisers for the extraction of red pigment.
This forest is still widespread in certain parts, in the states of Paraná and Santa Catarina. In other areas it occupies mainly the narrow zone of the Atlantic escarpment, formed by crystal rocks. The Atlantic Forest is a mountainous rain forest, covering mostly mountains from 800 to 1700 meters high. It suffers the influence of sea winds called “alíseos” (tropical easterlies) which cool down when climbing the steep slopes of the mountains, condensing and causing the fog of the Serra do Mar escarpment, where the average rain fall is around 2000 mm a year. In some regions, such as Boracéia (São Paulo state), even 4000 mm a year. The humidity of these areas depends on their distance from the sea. In some places evening temperatures are considerably low. In the Atlantic Forest average temperatures vary from 14º C to 21º C; the absolute minimum, in the South of the country, might get to -6ºC; the maximum temperatures achieve 35ºC.
The great humidity facilitates the existence of a rich flora of mosses and ferns, besides innumerable epiphytes, such as orchids and bromelias. Some trees, such as the pink “jequitiba”, grow to heights of 40 metres. Palms are common, including the ones from which palm hearts are extracted for food consumption. The highest areas present high altitude grasslands. Between the heights of 300 and 800 metres there is another type of forest with shorter trees, up to 25 metres high.
The rich endemic fauna is characterised mainly by multi-coloured butterflies, frogs, many bird species and wild mammals. The “muriqui” (spider monkey, Brachyteles arachnoides), an endemic type of primate, is the biggest monkey in the continent. There are native bee species important to the canopy’s pollination, like the “gurupu” bee (Melipona bicolor).
Whilst the various types of agriculture and fire wood industry caused the destruction of the Atlantic Forest, the cacao cultures make use of the vegetation. Currently in serious economic and phyto-sanitation crisis, this agriculture has been the target of conservationist programs aimed at reducing the destruction of the forests for the sale of wood, promoted by farmers in financial difficulties. A Reserve of the Biosphere of Unesco, recently established, includes areas of a high degree of preservation of the Atlantic Forest.
The “Mata de Araucárias” (needle-leaved pinewoods), a subtropical forest in the South of the country, has occupied around 15% of the Brazilian territory in the past. Today it is largely devastated, for being in an area of high agricultural and industrial development. The “Araucária” pine, a characteristic species, has suffered imensily with cuts by the wood industry. However, there are still samples of the forest with “Araucária” in the states of São Paulo, Paraná, Santa Catarina and Rio Grande do Sul. Many species of this forest, such as the “xaxim” fern, the “gralha azul” (blue crow) and “jacutinga” (piping guan), are today on the verge of extinction. There are also pine trees scattered among the semi-deciduous Atlantic vegetation, in transition areas.
In the interior of Brazil, and typically in rocks, there are many caves rich in geological formations, which hold an interesting fauna of blind fish and crustaceans.
Another important environment is the “Manguezal” (mangrove swamps), a tidal forest, formed by a few species of trees, but which has a fundamental role as source of food for the marine fauna. Brazil is especially rich in “manguezais”, which are already being monitored by satellites. Alongside them, in the sandy alluvion soils, there is frequently a vegetation of “restinga”, woodlands of low and bushy vegetation, that occupy sandy grounds.
Occupying less expressive territorial areas, but ecologically relevant, there are the alpine pastures, the “cocais” (palm tree woodlands) of the North, the “campos” (grasslands) of Rio Grande do Sul, and the sandy and rocky beaches, among other environments that characterise and enrich Brazil. The reefs of Abrolhos, a small area of coral reefs, have the largest rate of associated endemic species of corals and marine fauna.