Since most of the country is in an intertropical zone, with a predominance of low altitudes, there are hot climatic varieties in Brazil, with averages above 20º. There are six types of climatic variation found throughout the entire Brazilian territory: equatorial, tropical, tropical high, tropical Atlantic, semi-arid and subtropical. Each type of climate corresponds to a characteristic vegetal landscape, with its typical species.
Equatorial Climate – It is characterized by average temperatures between 24º and 26ºC and abundant rainfall (more than 2,500 mm / year). It is the type of climate found in the entire region of the Legal Amazon, with about 5 million km2. The typical vegetation of this region is the equatorial forest.
Tropical Climate – It presents hot and dry winter and hot and rainy summer. It is the climate found in extensive areas of the Central plateau and in the Northeast and Southeast regions. The average temperatures are above 20ºC, with an annual thermal amplitude of up to 7º and rainfall from 1,000 to 1,500 mm / year. The typical vegetation of the region where this type of climate is found is the savannah , with twisted grasses and bushes, with thick bark, leaves covered with hair and deep roots. Although there is plenty of water in the subsoil, the cerrado soil is acidic and not very fertile, with a high aluminum content. With two well-defined seasons – one dry and one rainy – in the dry season part of the trees lose their leaves to fetch water underground.
In the tropical climate region, gallery forests (riverside) can also be found in the valleys along the courses of the rivers.
The region known as Complexo do Pantanal is also dominated by a tropical climate, which, due to the alternation between the flood and drought season, has diversified vegetation, composed of typical species of forests, savanna, fields and caatinga.
Altitude Tropical Climate – It is characterized by average annual temperatures between 18º and 22º, with annual thermal amplitudes from 7º to 9º and precipitation between 1,000 and 1,500 mm / year. The summer presents more intense rains, while in the winter the cold masses can cause frosts. It is the climate found in the high parts of the southeastern Atlantic plateau, extending to the South region, up to the north of the state of Paraná and south of the state of Mato Grosso do Sul. The original vegetation of these regions is the tropical, dense forest, closed and varied, but not as rich as the vegetation found in the Amazon rainforest .
Atlantic Tropical Climate – It is found in the entire coastal strip, from the state of Rio Grande do Norte to the south of the state of Rio Grande do Sul. It is characterized by average temperatures between 18º and 26º, with increasing thermal amplitudes as you walk towards the south. The rains are abundant, exceeding 1,200 mm / year, but have an uneven distribution. On the northeastern coast they are concentrated in autumn and winter, while towards the south they are more constant in summer. The typical vegetation in this part of the territory is the tropical Atlantic forest, which has been largely devastated since the colonial period.
Semi-arid climate – Predominates in the northeastern sertão region and in the São Francisco river valley, also located in the Northeast region. It is characterized by high average temperatures, around 27ºC, with annual variations around 5º. Precipitation is low and irregular, reaching just 800 mm / year. The characteristic vegetation of this region is the caatinga, formed by forests of thorny shrubs and cacti. In the transition zone between the Amazon rainforest and the caatinga is a type of vegetation called mata dos cocais, formed by various types of palm trees such as babassu. carnauba and buriti from which raw materials are extracted for the production of oils, construction of houses and manufacture of waxes and fabrics.
Subtropical Climate – It is the predominant climate in the Temperate Zone to the south of the Tropic of Capricorn, characterized by average temperatures below 20º and annual variations between 9º and 13º. In high altitude areas, summer is mild and winter is harsh, with occasional snowfall. Precipitations are abundant, reaching 1,500 and 2,000 mm / year. The type of vegetation found in regions with a subtropical climate varies according to altitude. In the higher regions are the araucarias or pine forests. Grasslands predominate on the plains.
The vegetation that forms the Amazon rainforest is divided into three types: the terra firma forests; the igapó forests; and the lowland forests. In the forests of terra firma you can find the tallest trees, such as the Brazil nut and the caucho (from which the latex is extracted), which can reach 60 to 65 meters in height. In certain places the tops of these trees come together and block the passage of light, making the interior of the forest dark, poorly ventilated and humid. The igapó forests are found in the lower lands, close to the rivers and permanently flooded. In these regions the trees can reach 20 meters in height, but most of them are 2 to 3 meters. Its branching is low and dense, difficult to penetrate. The water lily is the most famous example of this type of lowland vegetation in the Amazon rainforest. Várzea forests are found in the midst of terra firma and igapó forests. Its composition varies according to the greater or lesser proximity to the rivers, but it is common to find in the region of lowland forests, large trees such as rubber, palm trees and jatobá.
They are common in coastal areas, more subject to tides and brackish water, especially at the mouths of rivers that flow into the Atlantic Ocean. Its typical species are vegetables with aerial roots, which have a high content of salts. The soils where this type of plant develops are flooded, unstable and poorly ventilated.