The Atlantic Forest (Portuguese: 'Mata Atlântica') is a region of tropical and subtropical moist forest, tropical dry forest, tropical savanna, semi deciduous forest and mangrove forests which extends along the Atlantic coast of Brazil from Rio Grande do Norte state in the north to Rio Grande do Sul state in the south, and inland as far as Paraguay and the Misiones Province of Argentina.
The Atlantic Forest region includes forests of several variations.
- The coastal restingas are low forests which grow on stabilized coastal dunes.
- The coastal forests, also known as Atlantic moist forests, are evergreen tropical forests with structures.
- Inland are the interior forests, also known as the Atlantic semi-deciduous forests, where many trees drop their leaves during the dry season.
- Further inland are the Atlantic dry forests, which form a transition between the arid Caatinga to the northeast and the Cerrado savannas to the east.
- Montane moist forests occur in the Serra do Mar and across the mountains and plateaus of southern Brazil, and are home to Araucaria and evergreen trees of the laurel (Lauraceae) and myrtle (Myrtaceae) families.
- Shrubby montane savannas occur at the highest elevations.
The Atlantic Forest is now designated a World Biosphere Reserve, which contains a large number of highly endangered species including the well known marmosets, lion tamarins and woolly spider monkeys. It has been extensively cleared since colonial times, mainly for the farming of sugar cane and for urban settlements. The remnant is estimated to be less than 10% of the original and that is often broken into hilltop islands.
The Amazon Institute is active in reforestation efforts in the northeastern state of Pernambuco, Brazil. During 2007, Joao Milanez and Joanne Stanulonis have planted 5,500 new trees in the mountains commencing with Gravata, adding to the precious little, ancient forest left.
During glacial periods, however, the Atlantic Forest is known to have shrunk to extremely small refugia in highly sheltered gullies, with most of the land area more recently occupied by the characteristic Atlantic Forest being occupied by dry forest or even semi-desert. Some maps even suggest the forest actually survived in moist pockets well away from the coastline, where its endemic rainforest species mixed with much cooler-climate species. Unlike refugia for equatorial rainforests, the refuges for the Atlantic Forest have never been the product of detailed identification.