| Alto Paraná Atlantic forests | |
| Map: | Alto Paraná Atlantic Forest.png |
| Map Size: | 240 |
| Biome: | Tropical and subtropical moist broadleaf forests |
| Biogeographic Realm: | Neotropical |
| Border: | Araucaria moist forests |
| Border1: | Bahia interior forests |
| Border2: | Campos Rupestres montane savanna |
| Border3: | Cerrado |
| Border4: | Humid Chaco |
| Border5: | Serra do Mar coastal forests |
| Border6: | Southern Cone Mesopotamian savanna |
| Border7: | Uruguayan savanna |
| Bird Species: | 586 |
| Mammal Species: | 213[1] |
| Area: | 471204 |
| Country: | Brazil |
| Country1: | Argentina |
| Country2: | Paraguay |
| State: | São Paulo |
| State1: | Mato Grosso do Sul |
| State2: | Paraná |
| State3: | Santa Catarina |
| State4: | Minas Gerais |
| State5: | Goiás |
| State6: | Rio Grande do Sul |
| State7: | Misiones Province |
| Habitat Loss: | 94.0 |
| Habitat Loss Ref: | [2] |
| Protected: | 5.95 |
| Protected Ref: | [3] |
The Alto Paraná Atlantic forests, also known as the Paraná-Paraíba interior forests, is an ecoregion of the tropical moist forests biome, and the South American Atlantic Forest biome. It is located in southern Brazil, northeastern Argentina, and eastern Paraguay.
The Alto Paraná Atlantic forests are an interior extension of the coastal forests, extending across the southern portion of the Brazilian Highlands. The ecoregion extends from the mouth of the Paraíba do Sul River eastward along the Paraíba valley lying behind the coastal Serra do Mar, and further eastward and northward along the basin of the Paraná River and its tributaries, forming a complex mosaic with the surrounding ecoregions.
The climate of the ecoregion is subtropical, with 1200mm1600mm of rainfall per year. The winter dry season extends from April to September.
The main vegetation type is semi-deciduous forests, akin to the other interior forest ecoregions of the Atlantic forests. Approximately 40% of the trees lose their leaves during the winter dry season.
5.95% of the ecoregion is in protected areas. Protected areas include Iguazú, Caazapa, Cerro Cora, Itatiaia, Ybycui, Ñacunday, San Rafael, and Saltos del Guairá national parks, and Caetetus Ecological Station, Paulo de Faria Ecological Station, Ybera Scientific Reserve, Alto Iguazu Wilderness Nature Reserve, Urugua-í Wildlife Reserve, and Marília Ecological Station.[3]