Cerrado
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The Cerrado (Portuguese: "closed" or "inaccessible") is a vast tropical savanna ecoregion of Brazil. The Cerrado is characterised by an enormous range of plant and animal biodiversity. According to the World Wide Fund for Nature, it is biologically the richest savanna in the world.
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[edit] Setting
The Cerrado is 1,916,900 km² (740,100 square miles) in size, covering the Brazilian states of Goiás, the Federal District, most of Mato Grosso, Mato Grosso do Sul, and Tocantins, the western portions of Minas Gerais and Bahia, the southern portions of Maranhão and Piauí, small portions of São Paulo, Roraima and Paraná. The Cerrado also extends into northeastern Paraguay and eastern Bolivia. The Cerrado accounts for 22% of Brazil's area, an area the size of Alaska. It is the largest savanna in South America.
Most of the Cerrado is located on large plateaus, broken by a network of depressions and river valleys. Several of South America's major rivers, such as the São Francisco, Tocantins, Araguaia, Xingu, and Paraguay rivers, have headwaters in the Cerrado. About 85% of the great plateau which occupies central Brazil was originally dominated by "cerrado" savanna landscapes, representing around 1.5 to 2 million km², or approximately 20% of the country's surface.
The Cerrado borders on all of Brazil's major ecological regions, including the Amazon basin to the north, the Chaco and Pantanal to the west, the Caatinga to the northeast, and the Atlantic forest to the east and south.
[edit] Climate
The Cerrado region's typical climate is hot, semi-humid, and notedly seasonal, with a dry winter season from May through September or October. The annual rainfall is around 800 to 1600 mm. The soils are generally very old, chemically poor and deep.
[edit] Flora
The "cerrado" landscape is characterized by extensive savanna formations crossed by gallery forests and stream valleys. Cerrado includes various types of vegetation. Humid fields and "buriti" palm paths are found where the water table is near the surface. Alpine pastures occur at higher altitudes and mesophytic forests on more fertile soils.
The savanna are not homogenous. There is great variation between the amount of woody and herbaceous vegetation, forming a gradient from completely open "cerrado" — open fields dominated by grasses — to the closed, forest-like "cerrado" and the "cerradão" ("big cerrado"), a closed canopy forest. Intermediate forms include the dirty field, the "cerrado" field, and the "cerrado" sensu stricto, according to a growing density of trees.
The "cerrado" trees have characteristic twisted trunks covered by a thick bark, and leaves which are usually broad and rigid. Many herbaceous plants have extensive roots to store water and nutrients. The plant's thick bark and roots serve as adaptations for the periodic fires which sweep the cerrado landscape. The adaptations protect the plants from destruction and make them capable of sprouting again after the fire.
As in many savannas in the world, the "cerrado" ecosystems have been coexisting with fire since ancient times; initially as natural fires caused by lightening or volcanic activity, and later caused by man.
The great habitat variability in the different types of "cerrado" supports an enormous diversity of plant and animal species. Recent studies, such as the one presented by J. A. Ratter and other authors in "Avanços no Estudo da Biodiversidade da Flora Lenhosa do Bioma Cerrado" (Advances in the Study of the Biodiversity of the Ligneous Flora of the "Cerrado" Bioma) in 1995, estimate the number of vascular plants at around 5000.
[edit] Fauna
More than 1600 species of mammals, birds and reptiles have been identified in the cerrado ("Cerrado's Fauna", Costa et al., 1981), including 180 reptile species, 113 amphibians, 837 birds and 195 mammals (WWF). Among the invertebrates, the most notable are the termites and the leaf-cutter ants ("saúvas"). They are the main herbivores of the cerrado, important to consuming and decomposing of organic matter, as well as constituting an important food source to many other animal species. The Giant Armadillo (Priodontes maximus) and Giant Anteater (Myrmecophaga tridactyla) are large insectivores that thrive on the ants and termites. Large herbivores include the Brazilian Tapir (Tapirus terrestris) and Pampas Deer (Ozotoceros bezoarcticus). Large predators include the Maned Wolf (Chrysocyon brachyurus), Cougar (Puma concolor), Jaguar (Panthera onca), Ocelot (Felis pardalis), and Jaguarundi (Felis yagouaroundi).
[edit] History
Taking advantage of the sprouting of the herbaceous stratum that follows a burning in the "cerrado", the primitive inhabitants of these regions have learned to use the fire as a tool, to increase the fodder to offer to their domesticated animals.
Until the mid 60's, agricultural activities in the "cerrados" were very limited, directed mainly at the extensive production of beef cattle for subsistence or the local market, since "cerrado" soils are naturally infertile for agricultural production. After this period, however, the urban and industrial development of the Southeast Region has forced agriculture to the Central-West Region. The transfer of the country's capital to Brasilia has been another focus of attraction of population to the central region. From 1975 until the beginning of the 80's, many governmental programs have been launched with the intent of stimulating the development of the "cerrado" region, through subsidies for agriculture. As a result, there has been a significant increase in agricultural and cattle production. On the other hand, the urban pressure and the rapid establishment of agricultural activities in the region have been rapidly reducing the bio-diversity of the ecosystems.
[edit] Agriculture
Nowadays the "cerrado" region contributes with more than 70% of the beef cattle production in the country ("Pecuária de Corte no Brasil Central"; Beef Cattle Production in Central Brazil, Corrêa, 1989), and thanks to irrigation and soil correcting techniques it is also an important production centre of grains, mainly soya, beans, maize and rice. Great extensions of "cerrado" are also utilised in the production of cellulose pulp for the paper industry, with the cultivation of several species of Eucalyptos and Pinus, but still as a secondary activity.
The region is increasingly threatened by single-crop monoculture plantations (particularly soybeans), the expansion of agriculture in general, and the burning of the vegetation for charcoal.
Nobel Peace Prize laureate Norman Borlaug has described the Cerrado as one of Earth's last remaining arable frontiers for the expansion of agriculture. The 2006 World Food Prize was awarded to former Brazilian Minister of Agriculture Alysson Paolinelli, soil scientist Edson Lobato (also of Brazil), and American soil scientist A. Colin McClung for their leadership in soil science and policy implementation that opened the Cerrado to agricultural and food production.
[edit] Conservation
The Cerrado is one of the most threatened ecosystems in Brazil, suffering effects of the agricultural activities, criminal fires, and other anthropic effects. Less than 3% of this domain is protected by law, and some of 10% are regions without human interference.
The conservation of the "cerrados" natural resources is represented by different categories of conservation units, according to specific objectives: eight national parks, various state parks and ecological stations, comprising around 6.5% of the total "cerrado" area ("Cerrado: Caracterização, Ocupação e Perspectiva"; Cerrado: Characterisation, Occupation and Perspectives; Dias, 1990). However, this extension is still insufficient and more conservation units need to be created for the protection of the bio-diversity that is still preserved.
[edit] See also
[edit] References
- Oliveira, Paulo S.; Marquis, Robert J. The Cerrados of Brazil: Ecology and Natural History of a Neotropical Savanna (2002) New York City: Columbia University Press ISBN 0-231-12043-5
- (Portuguese) BRANDÃO, M.; GAVILANES, M. L. (1992). Espécies árboreas padronizadoras do Cerrado mineiro e sua distribuição no Estado. Informe Agropecuário 16 (173): 5-11.
- (Portuguese) BRANDÃO, M.; CARVALHO, P. G. S.; JESUÉ, G. (1992). Guia Ilustrado de Plantas do Cerrado. CEMIG.
- CASTRO, A. A. J. F., MARTINS F. R., TAMASHIRO, J. Y., SHEPHERD G. J. (1999). How rich is the flora of Brazilian Cerrados? Annals of the Missouri Botanical Garden 86 (1): 192-224.
- (Portuguese) COUTINHO, L. M. Cerrado São Paulo: University of São Paulo.
- RATTER, J.A.; RIBEIRO,J.F. & BRIDGEWATER, S. (1997) The Brazilian Cerrado vegetation and Threats to its Biodiversity. Annals of Botany, 80: pp. 223-230.
- (Portuguese) LEITÃO FILHO, H.F. (1992). A flora arbórea dos Cerrados do Estado de São Paulo. Hoehnea 19 (1/2): 151-163.
- (Portuguese) MENDONÇA, R. C.; FELFILI, J. M.; WALTER, B. M. T.; SILVA, M. C.; REZENDE, FILGUEIRAS, T. S.; NOGUEIRA, P. E. Flora vascular do bioma Cerrado. ("Vascular flora of Cerrado biome") IBGE
- GOTTSBERGER, G.; SILBERBAUER-GOTTSBERGER, I. (2006): Life in the Cerrado Reta Verlag, Ulm 2006, ISBN 3-00-017928-3 Volume 1, ISBN 3-00-017929-1 Volume 2
[edit] External links
- "2006 World Food Prize winners opened Brazil's 'closed lands'" - press release
- Cerrado - Brazilian Government
- Cerrado (World Wildlife Fund)
- Cerrado biodiversity Hotspot (Conservation International)
- Nature Conservancy in Brazil - Cerrado
- The Biodiversity of the Brazilian Cerrado
- The Cerrado Flora in a CD-ROM
