Arboreal Diversity of the Atlantic Forest of Southern Brazil: From the Beach Ridges to the Paraná River

The Atlantic Forest (a hotspot for conservation) used to be the second largest tropical moist forest of South America (Oliveira-Filho & Fontes, 2000). It originally covered 20% (around 1.5 million km2) of the Brazilian territory and occupied highly heterogeneous environmental conditions (Ribeiro et al., 2009). Nowadays, however, the Atlantic Forest covers less than 1% of the country or 7.5% of remnants (Myers et al., 2000). When intermediate secondary forests and small fragments (< 100 ha) are included, this contribution increases, ranging from 11.4 to 16% (Ribeiro et al. 2009). The Atlantic Forest still comprises 20000 plant species, 8000 being endemic (Myers, 2000). For instance, in the 1950s, 40% of the Atlantic Forest still covered almost all the state of Parana in Southern Brazil (Fundacao SOS Mata Atlântica et al., 1998). During the following three decades, habitats that took thousands of years to evolve continued to be destroyed. What remains today covers an area 9.5 times smaller (10.58%) than the original area (Fundacao SOS Mata Atlântica & INPE, 2010). This coincided with a period when the government aimed at an “economic development”. However, this erroneous decision caused an irreparable loss of ecosystem functions (e.g. amount and quality of water, soil, carbon stocks, biodiversity, etc). Once more, immediate “development” led to the loss of a valuable ecosystem that had potential to bring true and sustainable development. The respect for the natural dynamics of ecosystems and species evolution is rarely presented in environmental discussions. Therefore it is timely to study biodiversity and to promote its management and restoration. This chapter aims at discussing tree diversity of different formations of the Atlantic Forest in Southern Brazil, using data from phytosociological studies carried out in the state of Parana. This study attempts to assess the following questions: What ecosystems are understudied in terms of phytosociological surveys? Are the tree species richness and diversity of the different formations of these Atlantic Forests sufficiently known? What are the tree species richness and the diversity when considering only individuals found in phytosociological surveys? What species are the most abundant in each ecosystem evaluated? What are the differences and similarities among these formations?