Rio Grande do Sul,
at the southern extremity of Brazil, has great biogeographical interest, being the
transition belt between the tropical landscapes of the Brazilian Southeast and the
subtropical and hot-temperate scenery of the Uruguayan-Argentinean space.
The "pampa", our South American steppe, begins at the southern edge
of the South Brazilian plateau. On the coastal plain and on the Atlantic slopes of the
Serra Geral, the Brazilian Atlantic forest reaches its southern limit in Rio Grande do
Sul.
The South Brazilian biota is formed, therefore, chiefly by species with northern
and tropical distribution. But species with southern distribution can also be found. Both
groups meet within the boundaries of Rio Grande do Sul State. 
On the photo (click on it, it's a thumbnail !),
the typical scenery of the South Brazilian uplands
The low temperatures on the uplands , frequently below
zero during the winter, favour the Araucaria angustifolia pine tree forests, while
the southern plains, with summer maximal temperatures surpassing 35 Celsius, show
predominantly a grassland vegetation. Tropical and subtropical rain forest can be found
mainly in the humid valleys and riversides and on the hillsides of the South Brazilian
crystalline shield.
Aechmea nudicaulis, A.gamosepala, Nidularium procerum, Canistrum
lindenii, Vriesea vagans, V.gigantea and V.scalaris are typical examples of the
northern flora. Tillandsia duratii is a southern type that reaches higher
latitudes and withstands wintry conditions. South Brazil has developed some interesting
cases of endemism in Bromeliaceae, as for instance, eight species of Dyckia (alba,
choristaminea, elisabethae, hebdingii, irmgardiae, retroflexa, retardata and selloa),
that occur exclusively in the referred area. |
