Atlantic forest

Description

The Atlantic forest is one of the most diverse and biologically rich forests in the world, but also one of the most highly threatened, with only around eight percent of its original cover remaining ^{(1) (2)}. Also known as the Atlantic rainforest or Mata Atlântica, it comprises a unique series of South American forest ecosystems, which have long been isolated from the Atlantic forest’s larger and more famous neighbour, the Amazon rainforest ^{(1) (3) (4)}.

Despite the scale of its destruction, the Atlantic forest possesses a diverse and...

Atlantic forest fact file

• Description
• Range
• Biodiversity
• Threats
• Conservation
• Find out more
• Glossary
• References

Description

The Atlantic forest is one of the most diverse and biologically rich forests in the world, but also one of the most highly threatened, with only around eight percent of its original cover remaining ^{(1) (2)}. Also known as the Atlantic rainforest or Mata Atlântica, it comprises a unique series of South American forest ecosystems, which have long been isolated from the Atlantic forest’s larger and more famous neighbour, the Amazon rainforest ^{(1) (3) (4)}.

Despite the scale of its destruction, the Atlantic forest possesses a diverse and fascinating range of species, many of which are found nowhere else, and as a result it has been designated a global ‘hotspot’ of biodiversity ⁽¹⁾. Although parts of it receive as much rainfall as the Amazon, the Atlantic forest is generally cooler and experiences greater temperature fluctuations ⁽⁵⁾, with a climate that ranges from tropical to subtropical ⁽⁶⁾. It also covers a wide range of latitudes and altitudes, and this variability contributes to its vast array of different species ^{(2) (5)}.

The Atlantic forest can be divided into a number of habitat types. In the lowlands, the coastal Atlantic forest occupies a narrow strip of land along the Brazilian coast, and comprises mainly tropical moist broadleaf forest ^{(1) (5)}. Further inland, deciduous and semi-deciduous forest extends across mountain foothills and slopes ^{(1) (2) (4) (5) (6) (7)}, while forests in the cooler south are often dominated by the Parana pine (Araucaria angustifolia) or by laurel species (Lauraceae) ^{(2) (4) (6) (7)}. The Atlantic forest also includes other associated habitats such as mangrove forests, high-altitude grasslands (‘campo rupestre’), and coastal forests and scrub on sandy soils, known as restinga ^{(2) (5) (6) (7)}.

Range

The Atlantic forest is found on the east coast of South America, stretching along the coast of Brazil from the states of Rio Grande do Norte to Rio Grande do Sul. It also extends inland into eastern Paraguay and the Misiones province of northeast Argentina ^{(1) (4) (8) (9)}, and includes several islands off the Brazilian coast, such as the archipelago of Fernando de Noronha ⁽¹⁾. Although it occupies only a narrow strip of coast in northeast Brazil, the Atlantic forest extends up to 600 kilometres inland in the south ⁽¹⁾, and reaches elevations of around 2,900 metres in the Serra do Mar mountain range ⁽⁶⁾.

Estimated to have once covered over a million square kilometres ^{(1) (3) (8) (10)}, the Atlantic forest has now been reduced to a total area of just under 100,000 square kilometres, and what remains is highly fragmented ^{(1) (6)}.

Biodiversity

Plants

An incredible eight percent of the world’s plant species occur in the Atlantic forest ⁽⁹⁾, with 8,000 out of a total of 20,000 or more plant species found nowhere else ^{(1) (4)}. In particular, more than half of the Atlantic forest’s trees are endemic ^{(1) (5)}, including the pau brasil (Caesalpinia echinata) and the Brazilian rosewood (Dalbergia nigra) ⁽¹⁾, which produces one of the most highly prized timbers in Brazil ⁽¹¹⁾. Tree diversity in the Atlantic forest is one of the highest in the world, and in some parts over 450 different species have been recorded in a single hectare ^{(1) (3) (7) (8)}. These forests also support a huge variety of other plants, including ferns, mosses, lianas, orchids and bromeliads ⁽⁹⁾.

Mammals

In addition to its huge plant diversity, the Atlantic forest is home to an astonishing range of animal life. In total, around 264 mammal species have been recorded there, including endemic species such as the maned three-toed sloth (Bradypus torquatus) and shrewish short-tailed opossum (Monodelphis sorex) ^{(1) (3) (4) (9)}. Of the region’s 26 primates, perhaps the most famous are the two endemic primate groups, the lion tamarins, including the golden lion tamarin (Leontopithecus rosalia) and black-faced lion tamarin (Leontopithecus caissara), and the muriquis or woolly spider monkeys, comprising the northern muriqui (Brachyteles hypoxanthus) and southern muriqui (Brachyteles arachnoides) ^{(1) (3) (4)}.

Birds

An estimated 936 bird species occur in the Atlantic forest, and many of which are highly threatened, with at least one, the Alagoas curassow (Mitu mitu), classified as Extinct in the Wild ⁽¹¹⁾. Examples of the Atlantic forest’s unique bird life include the red-billed curassow (Crax blumenbachii), Brazilian merganser (Mergus octosetaceus), seven-coloured tanager (Tangara fastuosa), and threatened parrots such as the red-browed Amazon (Amazona rhodocorytha) and blue-chested parakeet (Pyrrhura cruentata) ^{(1) (3) (4)}.

Reptiles and amphibians

The Atlantic forest is home to around 311 reptile species, including the broad-snouted caiman (Caiman latirostris), Lutz’s tree iguana (Liolaemus lutzae), and turtles such as the Brazilian snake-necked turtle (Hydromedusa maximiliani). Seventeen species of Bothrops snakes are found in the Atlantic forest ^{(1) (4)}, such as the Critically Endangered golden lancehead (Bothrops insularis), which occurs only on a single, tiny island off the Brazilian coast ⁽¹¹⁾.

Amphibian diversity in the Atlantic forest is high, with 60 percent of the estimated 483 amphibian species found nowhere else. There is also one endemic family, the Brachycephalidae ^{(1) (4)}, which includes species such as the poorly-known shield toad (Brachycephalus pernix). Some the Atlantic forest’s amphibians, such as the Itatiaia highland frog (Holoaden bradei), are only known from single, tiny areas, and are classified as Critically Endangered ^{(1) (11)}.

Fish and invertebrates

Over a third of the Atlantic forest’s 350 or more freshwater fish species are endemic to the region ^{(1) (4)}, and invertebrate diversity is also likely to be high. For example, at least 2,120 butterfly species and 88 tiger beetles have already been recorded from this diverse area ⁽⁴⁾. Some of the Atlantic forest’s most charismatic invertebrates include the Brazilian salmon pink tarantula (Lasiodora parahybana), the giant metallic ceiba borer (Euchroma gigantea), and the brightly-coloured butterfly Agrias claudina.

Threats

Although less well known than the Amazon rainforest, the Atlantic forest is much more highly endangered, and is considered one of the most threatened ecosystems in the world ^{(7) (8) (10) (12)}. Whereas around 20 percent of the Amazon has been lost ⁽⁵⁾, 92 percent of the Atlantic forest has now gone ^{(1) (2) (4)}, with the greatest destruction in the coastal regions of the northeast ^{(1) (4)}. The forest that does remain is severely fragmented, and only an estimated two percent comprises undisturbed primary forest ⁽¹⁰⁾. As a result, much of the Atlantic forest’s unique wildlife is threatened with extinction, and 148 of its vertebrate species are classified as Critically Endangered, Endangered or Vulnerable on the IUCN Red List ^{(1) (11)}. Of these, 104 species are found nowhere else ⁽¹⁾, so depend entirely on the Atlantic forest for their survival.

The destruction of the Atlantic forest began centuries ago, when European settlers started clearing the forest for timber and cattle ranches, and to grow sugarcane, coffee and cocoa ^{(1) (2) (10)}. More recently, land has been converted to soy cultivation and pine and eucalyptus plantations ^{(1) (2)}. Firewood harvesting, illegal logging, road building, hunting, plant collection and the spread of invasive species are continuing problems ^{(2) (3) (6) (8) (10)}, and the region’s river systems have been affected by pollution, drainage and dam construction ^{(2) (7) (10)}. In Argentina, the cultivation of yerba mate (Ilex paraguariensis) and tobacco are particular threats, while the expansion of soy cultivation is the main problem in Paraguay ^{(1) (8)}.

Further problems associated with forest clearance include soil erosion and a rapid loss of soil fertility, meaning farmers have to clear further land to maintain crop yields ^{(5) (10)}. Many forest fragments are also too small and isolated to support species in the long term ^{(2) (8)}.

Compounding these threats, the Atlantic forest coincides with the most heavily populated and industrialised part of Brazil, home to 70 percent of its population and two of the world’s largest cities, Rio de Janeiro and São Paulo ^{(1) (2) (3) (4) (8) (9)}. Brazil’s rapid economic development in recent decades has only increased the pressures on the Atlantic forest, bringing with it many problems associated with urbanisation and human population growth ^{(1) (2)}.

Conservation

The Atlantic forest has been described as the cradle of the environmental movement in Brazil ^{(1) (2) (4)}, and conservation efforts for this fragile ecosystem have increased significantly in recent decades ^{(1) (2) (4) (6)}. Many protected areas have been established ^{(1) (2) (4) (6)}, the largest being the Serra do Mar State Park ⁽⁸⁾. However, many of these areas are small and receive varying degrees of protection, and overall only a tiny fraction of the forest has protected status ^{(2) (4) (6) (9)}. In addition, many of the Atlantic forest’s most threatened species do not occur in any protected area ⁽⁶⁾.

Major conservation initiatives for the Atlantic forest include the establishment of the ‘Atlantic Forest Biosphere Reserve’, which extends through 14 Brazilian states, as well as projects such as the Brazilian Natural World Heritage Sites Program and the Central Biodiversity Corridor ^{(1) (6)}. A range of organisations, such as WWF ^{(3) (8)}, SOS Mata Atlântica ⁽⁷⁾, The Nature Conservancy ⁽⁹⁾, REGUA ⁽¹⁰⁾ and the World Land Trust ⁽¹²⁾, are also working to protect and restore the forest, to expand protected areas, and to raise awareness through environmental education. Initiatives focused on some of the Atlantic forest’s most charismatic ‘flagship’ species, such as the lion tamarins and muriquis, have already helped raise awareness and increase forest protection ^{(4) (6)}.

Conservation in the Atlantic forest also needs to take into account the needs of local people, and it will be vital to develop incentives and sustainable alternatives to help alleviate poverty, as well as to protect the forest ^{(6) (7) (9)}. Such schemes have already had success at reducing deforestation in parts of Paraguay ⁽⁸⁾, and also help to preserve the forest’s vital services, such as a secure water supply, the prevention of soil erosion, and climate regulation ^{(7) (8)}. Conservation priorities for the Atlantic forest also include establishing habitat ‘corridors’ to link the remaining forest fragments ^{(1) (2) (4) (9)}, together with projects to monitor changes in forest cover ⁽³⁾ and to more fully document the forest’s vast biodiversity ⁽²⁾.

This unique forest still faces many pressures, but intensive conservation efforts, increased environmental awareness and better law enforcement provide hope that what remains of the Atlantic forest and its incredible diversity can be successfully protected ^{(2) (4) (5)}.

Find out more

To find out more about conservation in the Atlantic forest, see:

• Conservation International: Biodiversity Hotspots - Atlantic Forest:
  www.biodiversityhotspots.org/xp/Hotspots/atlantic_forest/Pages/default.aspx
• Earthwatch Institute - Latin America Regional Climate Centre:
  www.earthwatch.org/europe/rcc_latinamerica
• The Nature Conservancy: www.nature.org/wherewework/southamerica/brazil/work/art5080.html
• Reserva Ecológica de Guapiaçu (REGUA): www.regua.co.uk/
• SOS Mata Atlântica: www.sosmatatlantica.org.br/
• World Land Trust: www.worldlandtrust.org/projects/brazil.htm
• WWF: Atlantic Forests: wwf.panda.org/about_our_earth/ecoregions/atlantic_forests.cfm

Glossary

Biodiversity

short for biological diversity, biodiversity is a term used to define the great diversity of life on earth, or more specifically, in a particular habitat or ecosystem.

Deciduous forest

forest consisting mainly of deciduous trees, which shed their leaves at the end of the growing season.

Endemic

a species or taxonomic group that is only found in one particular country or geographic area.

Invertebrates

animals with no backbone, such as insects, crustaceans, worms, molluscs, spiders, cnidarians (jellyfish, corals, sea anemones) and echinoderms.

Primary forest

forest that has remained undisturbed for a long time and has reached a mature condition.

Vertebrates

animals with a backbone, including mammals, birds, reptiles, amphibians and fish.

References

1. Conservation International: Biodiversity Hotspots - Atlantic Forest (January, 2010)
   http://www.biodiversityhotspots.org/xp/Hotspots/atlantic_forest/Pages/default.aspx
2. Galindo-Leal, C. and Câmara, I. de G. (Eds.) (2003) The Atlantic Forest of South America: Biodiversity Status, Threats, and Outlook. Center for Applied Biodiversity Science, Conservation International and Island Press, Washington D.C.
3. WWF: Atlantic Forests (January, 2010)
   http://wwf.panda.org/about_our_earth/ecoregions/atlantic_forests.cfm
4. Mittermeier, R.A., Gil, P.R., Hoffmann, M., Pilgrim, J., Brooks, T., Mittermeier, C.G., Lamoreux, J. and Da Fonseca, G.A.B. (2004) Hotspots Revisited. CEMEX, Mexico City.
5. Iracambi - The Atlantic Rainforest (January, 2010)
   http://www.iracambi.com/english/atlantic_rainforest.shtml
6. Tabarelli, M., Pinto, L.P., Silva, J.M.C., Hirota, M. and Bedê, L. (2005) Challenges and opportunities for biodiversity conservation in the Brazilian Atlantic Forest. Conservation Biology, 19(3): 695-700.
7. SOS Mata Atlântica (January, 2010)
   http://www.sosmatatlantica.org.br/
8. WWF-UK: Atlantic Forest (January, 2010)
   http://www.wwf.org.uk/what_we_do/safeguarding_the_natural_world/forests/forest_work/atlantic_forest/
9. The Nature Conservancy (January, 2010)
   http://www.nature.org/wherewework/southamerica/brazil/work/art5080.html
10. Reserva Ecológica de Guapiaçu (REGUA) (January, 2010)
    http://www.regua.co.uk/
11. IUCN Red List (January, 2010)
    http://www.iucnredlist.org
12. World Land Trust (January, 2010)
    http://www.worldlandtrust.org/projects/brazil.htm