Caatinga
While Brazil is known for its rain forests, much of the country encompasses more arid habitats, including the semiarid scrub forests of the Caatinga. One of the most populated semiarid regions in the world, the Caatinga is so altered that only a few ecologically important examples of natural habitat remain.
Caatinga is the natural vegetation in the sertao region of the northeastern part of Brazil. The name "caatinga" is a indigenous word meaning "open forest" or "open vegetation". It covers about 700,000 km2. The Caatinga has a semi-arid climate with average annual temperatures of about 28 °C. The area has a very hot and dry winter and a hot and rainy summer. The rivers of the caatinga only run during the rainy summers and in some places the streams are interrupted during the dry winters. The vegetation consists mainly of open shrubs that are resistant to drought.
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The Caatinga occupies 10 per cent of the Brazilian territory, reaching areas in the states of Ceará, Rio Grande do Norte, Paraíba, Pernambuco, Sergipe, Alagoas, Bahia, Piauí and Minas Gerais. One single ecoregion makes up for the Caatinga. |
Location
The Caatinga stretches across approximately 300,000 square miles (800,000 square kilometers) of northeastern Brazil. It is located between 3°S 45°W and 17°S 35°W, lying upon eight provinces of Brazil near the east coast by the Atlantic Ocean: Piauí, Ceará, Rio Grande do Norte, Paraíba, Pernambuco, Alagôas, Sergipe and Bahia. The caatinga is closest to the larger cities of Fortaleza, Recife and Salvador. The southern half of the caatinga is perforated with some areas of humid tropical forest.
Climate
Caatinga has only two distinguishable seasons. These are the winter, when it is very hot and dry, and the summer when it is hot and rainy. During the dry winter periods there is no foliage or undergrowth. The vegetation is very dry and the roots begin to portrude through the surface of the stony soil. They do this in order to absorb water before it is evaporated. All leaves fall off the trees to reduce transpiration in order to lessen the amount of water that is lost in the dry season. During the peak periods of drought the caatinga's soil can reach temperatures of up to 60 °C. With all the foliage and undergrowth dead during the drought periods and all the trees having to leaves the caatinga has a grey, desert-like look
The drought ends at the end of the year and it begins to rain in the newcoming year. With the coming of rain, the grey, desert-like landscape starts to transform into a much greener land. Small plants start growing in the now moist soil and trees grow back there green leaves. At this time the waters in the rivers start to fill up and the streams begin to flow again. The parts of the river that were dried out now have flowing water again.
People
People use many plant species from the caatinga region. Palms are very important to the economy in northeast Brazil. People from this area are greatly dependant on extraction from babassu, carnaúba, tucúm and macaúba, from which lauric and oleic oils are made from. Many trees are also used for lumber in this area, including these species: Anadenanthera macrocarpa, Ziziphus joazeiro, Amburana cearensis, Astronium fraxinifolium, Astronium urundeuva, Tabebuia impetiginosa, Tabebuia caraiba and Schinopsis brasiliensis, Cedrela odorata, Dalbergia variabilis, Didymopanax morototoni and Pithecellobium polycephalum. Some plants are also used for medical purposes.
The poorest population in Brazil lives in the northeast, which also happens to be the most densely populated part of the country. Over 60 million people survive on the minimal vegetation of the caatinga. A very large part of the population depend on extraction from vegetation for over half of their income. Harvesting of the caraiba woodland for lumber has reduced it's size. This reduction may partly be the cause of the endangerment of the Spix's Macaw (cyanopsitta spixii).
Agriculture
In some places in the caatinga has very fertile soils. Inhabitants plant fruits in the fertile soil to extract from and eat, sell and export. Some regions are being irrigated, most notably the São Francisco River. This is very good news for farmers of the land, although salinization of the soil is becoming a threat since the land is irrigated with saline water. If there becomes a surplus in goods as a result of the new irrigation this area will start exporting a lot more products to outside of Brazil. The São Francisco River valley is currently exporting grapes, papayas and melons and may become a real competitor in the world marketplace.
Having and using all these resources have a down side. Due to excessive harvesting of fruits, along with excessive grazing by cattle and goats the population structure of some of the more important species are being affected. Deforesting for industrial use, fuel and charcoal is killing the vegetation. The combination of drought and misuse of the land are becoming a major threat. If these practises continue at the rate they do, desertification is possible, especially from the salinization from irrigation.
Vegatation
The caatinga can be separated by vegetation types into eight different areas. The caatinga forest has deciduous tropic broadleaved trees. The forest canopy is covers about 60% of the ground. This type of vegetation happens in wetter areas with more rainfall. The arborescent area is an area mainly of shrubs with some trees with less than 60% coverage. Aborescent-shrubby closed caatinga is forest with closed shrub and three coverage less than 60%. Aborescent-shrubby open caatinga is similar but with more shrubs and cacti. In the shrubby closed caatinga scrub is more common. The shrubby open caatinga areas occur on shallow soils and rocky outcrops; this area contains trees, cacti and bromeliads. The caatinga savanna is areas with some trees and some scrub. The rocky caatinga savanna contains less than 10% coverage of tropical scrub; these plants are protruding from cracks in rocks and pavements.
Animals
Animal life in the Caatinga has been adversely affected by hunting and habitat destruction. Many species have become extinct locally, while others, such as the three-banded armadillo, collared anteater, jaguar and robust tufted capuchin, endure in reduced numbers.
Bird species in the Caatinga include:
Cactus parakeet |
Lear´s Macaw |
Long Billed Wren |
Scarlet-throated tanage |
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Yellow-faced siskin |
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The Caatinga holds many surprises. It is one of the few arid places in the world where rivers flow through to the ocean. Additionally, scientists do not understand why some species seen in greater numbers in the Cerrado and Amazon basin manage to adapt and survive in the Caatinga. One theory is that some mammals condense and conserve their urine, allowing them to survive without fresh water for long periods of time.