This division is not only geographical, but also historical and economic, reflecting the complex dynamics that have shaped the country over the years.

In this post, we will unravel the concept of biome, explore the main biomes of Brazil, learn about their unique geographical characteristics, discover the incredible diversity of flora and fauna, understand how people live in these environments, and, most importantly, why environmental preservation is so vital. Get ready for a fascinating journey through the universe of Brazilian biomes and discover why they are fundamental to the balance of our planet!

What Are Biomes?

The term biome was created in 1943 by the North American ecologist Alfred Russel Wallace, derived from the Greek words "bio" (life) and "oma" (group or mass). A biome refers to a set of phytogeographic formations – plant communities that occupy the same geographical area. Expanding on this definition, biomes can also be understood as biological communities where living beings interact, forming distinct ecosystems. Depending on climatic conditions, each biome presents a distinctive type of vegetation which, in turn, attracts specific fauna.

Brazilian Biomes

Brazil is a true mosaic of biomes, each with its geographical, climatic, and biological particularities. The classification of Brazilian biomes was carried out by the geographer Aziz Ab'Sáber in 1970, dividing the territory into six main domains. Let's get to know some of them:

1. Amazon Rainforest

Geography and Relief

The Amazon Rainforest is the largest Brazilian biome, covering about 61% of the national territory and representing 5% of the planet's land surface. Its relief is predominantly characterized by lowlands, with the presence of plateaus, plains, and depressions formed millions of years ago by geological and climatic processes. The formation of the Andes, approximately 80 million years ago, was crucial for the current configuration of river beds, such as the Amazon River, which became the backbone of this vast biome.

Climate

Located near the Equator, the Amazon has an equatorial climate, hot and humid, with average monthly temperatures ranging between 24°C and 27°C. The region receives high rainfall, which can reach 4,000 mm per year, with rains distributed throughout the year and very short dry periods. This constancy of rainfall is essential for maintaining the dense forests and rich Amazonian biodiversity.

Soil

Despite harboring a vast amount of life, Amazonian soils are generally poor in nutrients, with only a superficial layer of organic nutrients. Only 8% of the Amazon territory has naturally more fertile soils, such as those in floodplains, rich in organic matter due to periodic floods that deposit nutrients in river beds.

Hydrography

The Amazon River is the main hydrographic system in the region, responsible for about 20% of the world's freshwater volume. Its numerous tributaries, such as the Negro, Madeira, and Tocantins, ensure a double period of annual floods, fundamental for navigation and maintenance of aquatic ecosystems.

Biodiversity

The Amazon is considered the largest biodiversity reserve in the world, with thousands of plant and animal species, many of which have not yet been cataloged. The flora is predominantly broad-leaved, dense, and hygrophilous, while the fauna is mostly arboreal, with species adapted to living in the treetops.

Fauna

The density of the canopies prevents light from entering, limiting undergrowth and, consequently, terrestrial animals. The Amazonian fauna includes parrots, toucans, monkeys, and marsupials, as well as an impressive diversity of insects and other invertebrates.

Vegetation

The Amazon rainforest is characterized by heterogeneous and perennial vegetation, adapted to the humid climate. With a diversity of 40 to 300 species of higher plants per hectare, the Amazon extends across several countries besides Brazil, including Venezuela, Colombia, Peru, Ecuador, and Bolivia.

Conservation Challenges

Despite its importance, the Amazon faces serious threats:

  • Deforestation: The expansion of agriculture, especially for soybean plantations and pasture creation, has led to the devastation of vast forest areas.
  • Illegal Hunting and Exploitation: Poaching and illegal logging compromise biodiversity and the integrity of ecosystems.
  • Climate Change: Changes in rainfall patterns and temperatures can drastically affect local flora and fauna.

The preservation of the Amazon is crucial not only for Brazil but for global climate balance, given its capacity to store large amounts of carbon and regulate hydrological cycles.

2. Caatinga

Geography and Relief

The Caatinga is a unique biome, located predominantly in the northeastern region of Brazil, covering about 10% of the national territory. Its relief is marked by interplateau depressions and residual mountains, such as those of Araripe and Grande. The pediplanation process, influenced by strong winds and physical weathering, has shaped the relief, creating an arid and fragmented landscape.

Climate

Characterized by a tropical semi-arid climate, the Caatinga faces scarce and irregular rainfall, with an average rainfall index of 278 mm per year, the lowest in Brazil. Temperatures are high, ranging between 24°C and 26°C, with little variation throughout the year. Strong and dry winds contribute to the region's aridity, making the vegetation adapted to extreme conditions.

Soil

Caatinga soils are generally shallow and, in some cases, saline. Despite irregular rainfall, the soil contains a good amount of basic minerals, favoring agricultural practice, although the irregularity of rainfall represents a challenge. Appropriate irrigation techniques could enhance the agricultural use of the region.

Hydrography

The Caatinga is mainly drained by the São Francisco River, one of the most important hydrographic basins in Brazil. In addition to it, rivers such as Jaguaribe, Acaraú, and Capibaribe are intermittent, drying up in times of drought, which limits their navigability and economic use.

Biodiversity

Despite adverse conditions, the Caatinga harbors a rich biological diversity, with a high rate of endemism:

  • Fauna: The Caatinga fauna includes about 185 species of fish, 44 lizards, 47 snakes, 4 turtles, 3 crocodiles, 49 amphibians, 350 birds, and 80 mammals, of which 15% are endemic. Endangered species such as the Spix's macaw and the Lear's macaw stand out for their urgent need for conservation.
  • Vegetation: The Caatinga vegetation is divided into three strata:
      1. Arboreal (8 to 12 meters): Trees adapted to the dry climate.
      2. Shrub (2 to 5 meters): Thorny shrubs resistant to drought.
      3. Herbaceous (below 2 meters): Xerophytic plants, such as cacti and bromeliads.

During the dry season, the vegetation takes on a thorny and rugged appearance, with many deciduous species losing their leaves to conserve water.

Conservation Challenges

The Caatinga faces several challenges that threaten its integrity:

  • Deforestation and Fires: Agricultural pressure and illegal hunting reduce vegetation cover and fragment natural habitats.
  • Loss of Biodiversity: Hunting and exploitation of natural resources lead to a decrease in populations of endemic and endangered species.
  • Climate Change: The irregularity of rainfall and rising temperatures aggravate the already adverse conditions of the biome.

The conservation of the Caatinga is fundamental to preserve its unique species and ensure the sustainability of communities that directly depend on this ecosystem.

3. Cerrado

Geography and Relief

Known as the Brazilian savanna, the Cerrado occupies about 20% of the national territory, spreading mainly across the Central Plateau. It is the second largest biome in Brazil and considered the savanna with the richest biodiversity in the world. Its relief is predominantly composed of crystalline and sedimentary terrains, plateaus, and mountains that shape an undulating and diverse landscape.

Climate

With a tropical semi-humid climate, the Cerrado has rainy summers and dry winters. Its temperatures range between 20°C and 28°C, with an average precipitation of 1,500 mm per year.

Soil

Although they are acidic and poor in nutrients, Cerrado soils have a high natural fertility in some areas, such as the patches of terra roxa in the south. The surface layer of decomposition and mycorrhizae help maintain vegetation even with nutrient leaching.

Hydrography

The Cerrado is drained by perennial rivers with a tropical regime. Its hydrographic basins are fundamental for maintaining the sources of Brazil's main rivers.

Biodiversity

The Cerrado is home to more than 10,000 plant species, with 4,400 endemic. The fauna includes 837 bird species, 161 mammals, 150 amphibians, and 120 reptiles, many of them endemic. Emblematic species such as the maned wolf, giant anteater, and jaguar are part of this vibrant ecosystem.

Conservation Challenges

The Cerrado faces several threats that compromise its integrity:

  • Agricultural Expansion: The growing demand for agricultural land and pastures leads to deforestation and habitat fragmentation, reducing natural areas and isolating species populations.
  • Intensive Land Use: The leaching of nutrients due to abundant rainfall and lack of vegetation cover increases soil erosion and degradation.
  • Fire: Fires, both natural and human-induced, alter the structure of vegetation and affect biodiversity.

Preservation Initiatives

Several actions are being implemented to save the Cerrado:

  • Biosphere Reserves and National Parks: Areas such as the Chapada dos Veadeiros and Emas National Parks protect large extensions of Cerrado, preserving biodiversity and water resources.
  • Sustainability Projects: Incentives for sustainable agriculture and management practices that preserve soil and native vegetation.
  • Education and Awareness: Campaigns to sensitize the population about the importance of the Cerrado and encourage active participation in its conservation.

Why Preserve the Atlantic Forest and the Cerrado?

The preservation of these biomes is crucial for several reasons:

  • Biodiversity: Both harbor unique species that do not exist anywhere else in the world, contributing to global genetic richness.
  • Ecosystem Services: The Atlantic Forest and the Cerrado play essential roles in climate regulation, nutrient cycling, and maintenance of hydrological cycles, ensuring water availability and soil quality.
  • Economic Sustainability: Many communities directly depend on these biomes for their survival, whether through agriculture, fishing, or sustainable tourism.
  • Climate Balance: The Atlantic Forest, in particular, is a large carbon reservoir, helping to mitigate global climate change.

The Importance of Preserving Biomes

Preserving biomes is essential not only to maintain biodiversity but also to ensure vital ecosystem services such as climate regulation, maintenance of water cycles, and soil protection. The destruction of these environments results in loss of species, climate imbalance, and negative impacts on human health.

Main Threats to Brazilian Biomes

  • Deforestation: Reduces vegetation cover, affecting biodiversity and water cycles.
  • Wildfires: Destruction of flora and fauna, contributing to global warming.
  • Agriculture and Livestock: Agricultural expansion that leads to the conversion of natural biomes into productive areas, causing soil erosion and nutrient loss.
  • Urbanization: Growth of cities that encroaches on natural areas, fragmenting habitats.

The Brazilian biomes are true natural treasures that harbor an immense diversity of life and play crucial roles in the global ecological balance. Understanding their characteristics and being aware of the threats they face are fundamental steps for their preservation. It is everyone's responsibility — governments, communities, and individuals — to adopt sustainable practices that ensure the conservation of these vital environments for future generations. Let's work together to care for these natural treasures and ensure they continue to flourish for a long time!

References

  • Ab'Sáber, A. (1970). Geography of Brazil. Rio de Janeiro: Edições do Brasil.
  • IBGE. (2023). Maps of Brazilian Biomes. Available at: https://www.ibge.gov.br
  • SOUZA, R. C. et al. (2020). Biodiversity and Conservation of Brazilian Biomes. São Paulo: Editora Universitária.
  • UNESCO. (1991). Serra da Capivara World Heritage. Available at: https://whc.unesco.org
  • YOSHIKAWA, T. S. (2008). Brazilian Biomes: Characteristics and Challenges. Porto Alegre: Editora Bookman.