Caatinga

Caatinga during the rainy season.

Caatinga (Portuguese pronunciation: [kaaˈtĩɡɐ]) is a type of desert vegetation, and an ecoregion characterized by this vegetation in interior northeastern Brazil. The name "Caatinga" is a Tupi word meaning "white forest" or "white vegetation" (caa = forest, vegetation, tinga = white).

Caatinga is a xeric shrubland and thorn forest, which consists primarily of small, thorny trees that shed their leaves seasonally. Cacti, thick-stemmed plants, thorny brush, and arid-adapted grasses make up the ground layer. Many annual plants grow, flower, and die during the brief rainy season.Template:MIR

Caatinga falls entirely within earth's Tropical zone and is one of 6 major ecoregions of Brazil, including the Amazon Basin, Pantanal, Cerrado, Caatinga, Atlantic Forest, and Pampas. It covers 850,000 km², nearly 10% of Brazil's territory. It is home to 15 million people and more than 2000 species of vascular plants, fishes, reptiles, amphibians, birds, and mammals.

Geography

Approximate vegetation map of Brazil. The Caatinga is brown

Caatinga covers the interior portion of northeastern Brazil bordering the Atlantic seaboard (save for a fringe of Atlantic Forest). It is located between 3°S 45°W and 17°S 35°W, extending across eight states of Brazil: Piauí, Ceará, Rio Grande do Norte, Paraíba, Pernambuco, Alagoas, Sergipe, Bahia, and parts of Minas Gerais, as well the southeasternmost point of Rio de Janeiro in Cabo Frio. The Caatinga includes several enclaves of humid tropical forest, known as the Caatinga enclaves moist forests.

The Caatinga is bounded by the Maranhão Babaçu forests to the northwest, the Atlantic dry forests and the Cerrado savannas to the west and southwest, the humid Atlantic forests along the Atlantic coast to the east, and by the Atlantic Ocean to the north and northeast.

The Caatinga comprises 850,000 km2, about 10% of the surface area of Brazil. By comparison, it's over nine times the surface area of Portugal from whence came its early settlers, and 20% larger than the U.S. state of Texas.

Climate

The 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 protrude 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, thus lessening 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 no leaves the Caatinga has a yellow-grey, desert-like look.

The Caatinga is a very dry place in Brazil. Droughts occur frequently in Caatinga. The drought usually ends in December or January, when the rainy season starts. Immediately after the first rains, the grey, desert-like landscape starts to transform and becomes completely green within a few days. Small plants start growing in the now moist soil and trees grow back their green leaves. At this time, the rivers that were mostly dry during the past 6 or 7 months, start to fill up and the streams begin to flow again.

History

Marcgrav (1638)

Spix & Martius (1817-1820)

colonization 1800's

Conservation

The Caatinga is poorly represented in the Brazilian Conservation Area network with only 1% in Integral Protection Conservation Areas and 6% in Sustainable Use Conservation Areas.

Ecology

Caatinga harbors a unique biota, with thousands of endemic species. Caatinga contains over 1,000 vascular plant species in addition to 187 bees, 240 fish species, 167 reptiles and amphibians, 516 birds, and 148 mammal species, with endemism levels varying from 9 percent in birds to 57 percent in fishes.

Flora

Authorities divide the Caatinga into microclimates in various ways depending on vegetation type.

Fauna

The Caatinga is home to nearly 50 endemic species of birds, including Lear's Macaw (Anodorhynchus leari), Spix's Macaw (Cyanopsitta spixii), Moustached Woodcreeper (Xiphocolaptes falcirostris), Caatinga Parakeet, Caatinga Antwren, Caatinga Black-tyrant and Caatinga Cacholote.

Endemic mammal species include: eleven rodents Caatinga vesper mouse, (Wiedomys pyrrhorhinos, Trinomys yonenagae, Trinomys albispinus minor, Trinomys albispinus sertonius, Thylamys karimii, Dasyprocta sp. n., Oryzomys sp. n., Oxymycterus sp. n., Rhipidomys sp. n. ssp. 1, and Rhipidomys sp. n. ssp. 2; Oliveira [126]); one primate (Callicebus barbarabrownae; Oliveira [126]); two bats (Xeronycteris vieira and Chiroderma sp. n; Gregorin and Ditchfield [127], and Gregorin et al. [128], resp.).

Economic exploitation

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 dependent 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.Template:MIR

Around 15 million people live in the Caatinga region, and are regarded as belonging the poorest inhabitants of Brazil.Template:MIR A very large part of the population depends on agricultural or forest industries for over half of their income. There are few drinkable water sources, and harvesting is difficult because of the irregular rainfall.

Agriculture

In some placesTemplate:MIR the Caatinga has very fertile soils. Inhabitants plant fruits in the fertile soil to process and eat, sell and export. The irrigated farms along the São Francisco River in the municipalities of Petrolina and Juazeiro are currently exporting grapes, papayas and melons.

Irrigation

Some regions are being irrigated, most notably the São Francisco River. While this is very good news for some farmers, it has also had serious consequences for people who have always depended on the natural flow of the river. Big dams have brought an end to the high tides in the rainy season, which used to spread fertile mud over the fields creating a rich ground that could be used for agriculture during the dry season. Also, salinization of the soil is becoming a threat since big parts of the land are irrigated with saline water, thus sterilizing the soil.

Deforestation

Having and using all these resources has some negatives. Intensive agriculture, along with excessive grazing by cattle and goats is affecting the population structure of some of the more important plant and animal species. Deforesting for industrial uses like fuel and charcoal destroys the vegetation. The combination of drought and misuse of the land are becoming a major threat. Harvesting of the caraiba woodland for lumber has reduced its size. This reduction may have contributed to the endangerment of the Spix's Macaw.

See also

• Caatinga enclaves moist forests
• northeastern Brazil
• Sertão
• List of plants of Caatinga vegetation of Brazil

For Further Reading

• Llosa, Mario Vargas The War of the End of the World.

External links

• "Caatinga". Terrestrial Ecoregions. World Wildlife Fund.
• IBAMA
• Brazil Nature
• Caatinga: Brazilian national heritage threatened
• Associação Mãe-da-lua The Avifauna of northeastern Brazil