The Brazilian Atlantic Forest: A Shrinking Biodiversity Hotspot

Abstract

The Neotropical Atlantic Forest is one of the world's top biodiversity hotspot. Originally, the forest extended over 1.5 million km2 along the South American Atlantic coast, covering tropical and subtropical climates across highly heterogeneous relief conditions, which led to outstanding levels of endemism and species richness. Unfortunately, the Atlantic Forest has been historically altered by humans, which has resulted in severe habitat loss and fragmentation. The forest cover is now reduced to around 12% of its original extent, including regenerating areas and degraded forests, which are mostly spread in small fragments. As a result, many species are currently threatened to global extinction, with populations collapsing on local and regional scales. In this chapter, we reviewed the state of the art of Atlantic Forest biodiversity knowledge, poiting out the main achievements obtained by several research groups during the last decades. Additionally, we (1) proposed a new subdivision of biogeographical sub-regions into 55 sectors considering 2,650 subwatersheds, using niche theory and bioclimatic data; (2) describe the original and present distribution of the Atlantic Forest; and (3) relate the forest distribution to elevation and geomorphometric information (aspect and terrain orientation). Forest protection and restoration efforts, and potential ecosystem services are also examined as key topics driving the future of the Atlantic Forest biodiversity.