 |
 |
 |
 |
 |
 |
|
Atlantic Forest The Atlantic Forest is the second of the most expressive forests in South America, only losing to the Amazon Forest, the largest in the planet. Denominated the Atlantic Rain Forest, it is located in the Serra do Mar escarpment, which is part of the Atlantic Tropical Forestal Domain. This Forestal Domain extends itself for an area relatively parallel to the Brazilian coast, from Rio Grande do Norte to Rio Grande do Sul and is constituted by "seas of hills" and "chapadões" (large tablelands) covered in forest, with deep soils of perennial drainage.
The climate in the region comprised by the Atlantic Rain Forests has two seasons, defined mainly by the rainfall regime, despite being latitudinaly much variable. Whilst in the Brazilian Northeast average annual temperatures vary around 24ºC, in the Southeast and the South the annual averages are lower and the temperature might occasionally reach -6ºC. The Serra do Mar, represented by a chain of coastal mountains, presents a series of interruptions where the large belt of Rain Forests is also interrupted. The average altitude in this mountain chain is of 800 to 900 meters, with emerging peaks of around 1400 meters and escarps of up to 2000 meters. On the mountain tops there are fields of rocky outcrops and, exceptionally, over 1700 meters the forest gives place to alpine pastures. The Atlantic Forest extends itself along the mountains and slopes facing the sea, as well as along the coastal plains. It owes its existence to the elevated atmospheric humidity brought by maritime winds. The humid winds condense by the coast in the form of rains, when climbing to the cold areas of higher altitude. Besides the high rainfall, there is, on mountain tops, water condensation
in the form of fog. This occurs even in summer and spring months,
during the hot hours of the day. Nowadays, the Brazilian Atlantic forests are almost completely devasted, there remains only around 5% of preserved areas from their original extension, at the time of Brazil's discovery. The most representative section of what remains is found in the South and Southeast regions, where the landscape of steep escarpments makes difficult the access and devastation. The robust Atlantic Forest, with an arboreal vegetation of around 30 meters, and trees that surpass the canopy, reaching 40 meters of height, presents an intense shrubby vegetation on the inferior stratum. It is a forest of great diversity of vegetation with many ferns, including the arborescents, besides terrestrial orchids and palm trees, among which the Euterpes edulis can be found. Around 10 meters high, it is from their trunks that palm hearts are extracted for food consumption. Besides moss carpets and innumerable fungi, the Atlantic Forest is very rich in lianas and epiphytes, such as ferns, orchids and bromeliads. These last ones, with their leaves disposed in rosettes, always retain a certain amount of water, creating a favorable habitat for the development of a particular fauna, such as various larvae and adult species of arthropods and frogs. In general, the fauna in this forest is predominantly adapted to the shade, and little tolerant of humidity, temperature and insolation variations. As a direct or indirect consequence of the devastation of the forest many species have been affected. Besides the terrestrial fauna, the Atlantic Forest also has a rich fauna of fish which inhabits the small streams that permeate forested areas. Many of these fish orientate themselves by vision, to localize food or reproductive partners, as well as for social behavior reasons. They are incapable of surviving in cloudy or clear waters, subjected to intense luminosity, as when the removal of the forest occurs. Besides, the maintenance of mild temperatures in the stream and soil is only possible thanks to the intense vegetable covering. The Atlantic Forest has, besides a richness of invertebrates, especially arthropods, an important fauna of vertebrates. However, many species are still unknown to science and risk not even being discovered if the destructive process of forests continues. One of the main characteristics of the fauna living in the Atlantic Forest, as in other tropical forests in the world, is the fact of being diversified and marked by the presence of many endemic species. With many of these species having a low population density, there is a great number of rare species. The preservation of endemic species of the Atlantic Forest is extremely worrying, in face of the current situation of devastation. Even the endemic species which have not yet had their populations reduced to critical numbers deserve special attention to survive. To mention an example, there is a great number of endemic species in the avifauna which have as their evolutive center the Serra do Mar, and that, with a geographic distribution extremely restricted, are found in a vulnerable situation. This is the case of the "pintor-verdadeiro" (Tangara fastuosa) in the forests of the states of Pernanbuco and Alagoas. There are around 25 species at risk of extinction listed among the Brazilian primates, and some of them are endemic of the Atlantic Forest. This is, for instance, the case of four species of capuchin monkeys (Leontopithecus spp) and of the spider monkeys (Brachyteles aracnoides), the largest of neotropical monkeys. The most affected areas of the Atlantic Forest are precisely the most important from
the conservationist point of view. They are the remaining forests of South Bahia and Espírito Santo,
which house the last examples of genus and species of plants and
animals threatened by extinction. In the Southeast region, where
great metropolis' like São Paulo and Rio de Janeiro were
developed in former areas of the Atlantic Forest, there are still
relatively large stretches, where areas of environmental protection
have recently been created and even turned into the Reserve of
the Atlantic Forest Biosphera. These are the last refuges of one
of the richest ecosystems in the world. |
Environment  |
