**3.1.3 Submontane formation**

This ecosystem comprises the lower portions of slopes of the mountain ranges and the Ribeira River Valley. According to IBGE (1992), this formation occurs between 30 and 400 m a.s.l.. However, Roderjan et al. (2002) adapted the upper limit of the Submontane formation to 600 m a.s.l., considering the regional scale. Results of a survey performed by Blum & Roderjan (2007) agree well with this limit. The Submontane Atlantic Rainforest generally occurs on Argisols, Oxisols and Cambisols, mainly in colluvial fans (Roderjan et al., 2002).

The dense canopy varies between 25 and 30 m in height and is characterized by high tree diversity and richness. *Virola bicuhyba*, *Sloanea guianensis*, *Aspidosperma pyricollum*, *Cedrela fissilis*, *Cariniana estrellensis*, *Pseudopiptadenia warmingii* and *Schyzolobium parahyba* are frequent in the canopy. *Bathysa australis*, *Pausandra morisiana*, *Euterpe edulis*, *Geonoma gamiova* and *Psychotria nuda* are common in the dominated strata (Leite & Klein, 1990; Maack, 2002; Roderjan et al., 2002; Pires et al., 2005; Blum, 2006).

This formation presents the highest floristic diversity of Southern Brazil due to the combination of factors like soils with good physical support and nutritional capacity, higher temperatures and well distributed rainfalls (Leite & Klein, 1990; Roderjan et al., 2002). These features also promote the development of dense and large-sized arboreal communities, associated with terrestrial and epiphytic strata, extremely rich and abundant (Blum, 2010).
