The Biomes in Brazil - IELTS Listening Answers & Explanations

To begin our topic on sustainable development in South America, I would like to briefly acquaint you with the 6 biomes present in the country. Each of these biomes has its own geographic and environmental features, has unique resources that people may exploit, and indeed, each is facing different threats from human development.

Biomes, if you recall, are regions that are climatically and geographically defined and contain distinct communities of plants and animals. They are sometimes named for the plant communities that occur such as forest, savannah, and grassland; whether these plants are evergreen or deciduous; and climatic factors as well, for example, tropical, temperate, etc.

All right, let's take a look at this map of Brazil. The largest biome in Brazil is the Amazonian Rainforest Biome, which you can see located in the north of the country. It's one of two rainforest biomes in Brazil; the second being the Atlantic rainforest Biome, which is located in a relatively narrow strip running up the eastern Atlantic coast. In the very southernmost part of Brazil, bordered by the Atlantic rainforest, lies the very small and relatively unstudied Pampas biome, which is grassland. Finally, stretching like a belt across the middle of the country, between the two rainforest biomes, lie the Pantanal, the Cerrado, and the Caatinga. Starting at the left of the map, you can see the smallest of the three, which is the Pantanal Biome a unique seasonally flooded wetland area. In the centre of the country is the Cerrado, the second largest biome in Brazil. Cerrado is tropical savannah - a scattering of grassland and deciduous forest that experiences a short dry season. Finally, the last biome, called Caatinga, is located between the Cerrado and the Atlantic forest in the north east of the country. The Caatinga has a very long dry season, lasting 8 to 9 months, and is covered in deciduous scrub.

So, let's begin with the Amazonian Rainforest Biome. As I mentioned previously, it's rainforest, and it's incredibly diverse. It contains the largest single reserve of biological organisms in the world. No one really knows how many species occur in the Amazon forest, but scientists estimate that there could be as many as 5 million. Recently this biome has been under a great deal of pressure from agriculture, with large swathes being cleared and burned to create pasture for the 19 million cattle that the area supports. However, the soils are acidic with very low levels of certain important minerals, and are quickly degraded when heavily grazed, which necessitates more clearing and burning of forest. The rainforest is further disturbed by selective logging of valuable tree species.

The second largest biome in Brazil is the Cerrado, which is a tropical savannah environment made up of sparse trees and drought resistant grasses. The Cerrado also contains a huge biodiversity; it's estimated that one third of Brazil's plant and animal species are located in this region. But since 1995, the cultivated pasture area in the Cerrado has increased by almost 70%. It is a common practice to use newly cleared land for the cultivation of crops for a few years, and then when it starts to degrade, to use it for pasture for cattle. The Cerrado now supports 72.3 million cattle, which amounts to 41 percent of the cattle in Brazil.

Next, we have the biome called the Caatinga, which is a tropical dryland with a dry season that lasts 8 or 9 months of the year. Vegetation is deciduous, sparse and thorny, and contains a high number of species endemic to Brazil. Agriculture is limited by the lack of water but this biome supports 8.8 million goats and 8.1 million sheep, besides 23.9 million cattle.

The Pantanal Biome, a wetland formed by the flooding of the rivers of the Paraguay basin, is the world's biggest flooded plain. Vegetation is patchy and variable; it consists of tall grasses, bushes, and widely dispersed trees similar to those of the Cerrado, except that in the Pantanal they are partially submerged for a portion of the year. Three million cattle are raised in this biome, however the available grazing area is limited by flooding so large areas can sustain only low numbers of animals. UNESCO recognizes it as a "World Biosphere Reserve" and also as a "World Natural Heritage Site." Ecotourism is becoming important in this region, which diversifies the economic activity.

The Atlantic Rain Forest is the most endangered biome in Brazil and also its most affluent region. It's the most important agricultural and industrial area of the country. It supports 36 million cattle, and most of the country's dairy production takes place there. More than 70% of the Brazilian population, the largest Brazilian cities and the production of about 80% of Brazil's gross domestic product are all located in what used to be the Atlantic Forest. Today, as a result, less than 10 per cent of the Atlantic forest is left. The Biome is also beginning to be recognised as ecologically very important; in the state of Bahia, for example, international researchers have identified a world record of 458 tree species in a single hectare of Atlantic Forest. That is even more diverse than the Amazon rain forest. At the moment, less than 2% of the remaining Atlantic forest is under protected status, and the scientific community is scrambling to secure what little undisturbed forest still remains.

Finally, the Brazilian Pampas Biome has a temperate climate - it's the only biome in Brazil that is not tropical. Grasslands scattered with shrubs and trees are the dominant vegetation. The shallow soil, originating from sedimentary rocks, often has an extremely sandy texture that makes it fragile and highly prone to water and wind erosion. The Pampas supports 26 million cattle and 6 million sheep, in mostly natural unmodified pastures; however this biome is being threatened with rapid conversion to the agriculture of cash crops.

All right, so, next week we will go into more detail about the economic policies of the Brazilian government in relation to the development of each of these biomes.