**3.1.1 Lowland formation**

In South Brazil, the Lowland formation (Coastal Plain Forest) is restricted to Quaternary coastal plains growing on tsites near to sea level to about 20 m a.s.l.. Poorly developed soils and the high susceptibility to flooding during the rainiest periods are remarkable factors that led to its typical floristic and structural composition (Leite & Klein, 1990; Veloso et al., 1991; IBGE, 1992; Roderjan et al., 2002; Pires et al., 2005).

Arboreal Diversity of the Atlantic Forest

of Southern Brazil: From the Beach Ridges to the Paraná River 115

structurally and physiognomic, the Montane and Submontane formations are similar (Roderjan et al., 2002; Pires et al., 2005). Cambisols (with no textural gradient) and Entisols

The main environmental factors that affect the differentiation between the Montane and Submontane formations (Lower Montane Forests) are the climate, the topography and the soils. In the Montane Atlantic Forest it can occur occasional frosts, which are extremely limiting for many typical species of Submontane formation, that are subject to milder climate. It should be noted that the geomorphological differences result in distinct pedologies. The Montane terrains are steep and dissected while the Submontane sites are

The canopy of the Montane Dense Rainforest is regular, varying about 20-25 m height. Several species of Lauraceae dominate in the upper strata, especially *Ocotea catharinensis*, *Ocotea odorifera, Ocotea bicolor* and *Cryptocarya aschersoniana. Aspidosperma pyricollum, Pouteria torta*, *Cabralea canjerana, Sloanea lasiocoma, Guapira opositta, Ilex paraguariensis* and *Guatteria australis* are also relevant. The lower strata are characterized by Myrtaceae, Rubiaceae and Monimiaceae families. Ferns (tree ferns) such as *Cyathea phalerata* and another species of Cyatheaceae are common in the understory (IBGE, 1992; Roderjan, 1994; Blum et al., 2001;

In the state of Paraná, faults belonging to the Brasiliano (or Pan African) Cycle and the Ponta Grossa Arch currently confine the Upper Montane Rainforests (or Cloud Forests), allowing such vegetation to reach areas close to the main tops of the Sea Mountain Range (Scheer et al., in press b). This formation generally occurs from 1200 m a.s.l (Roderjan et al., 2002), even though it can be found at 900 m a.s.l., in small isolated mountains due to geomorphological conditions and the "*Massenerhebung* effect" (Grubb, 1971). In larger mountains, such as the Paraná Peak, the typical Upper Montane Rainforest ranges from 1400 to 1850 m a.s.l.., interspersed with high altitude grasslands. The changes in vegetation from forests to grasslands are abrupt and include ecotonal areas with "dwarf forests" or shrubby physiognomy with species of both formations across a gradient of a few meters (2-5 m). Although typical Upper Montane Forests are composed by simplified tree associations, 346 vascular plant species have been detected in four mountain ranges (Scheer & Mocochinski, 2009). Small-sized trees ranging from 3 to 7 m tall, are subject to more restrict environmental conditions, such as low temperatures, strong winds and constant and heavy cloudiness, intense light radiation and shallow soils with low fertility and substantial histic horizons (Histosols and Leptosols). *Ilex microdonta*, *Siphoneugena reitzii*, *Myrceugenia seriatoramosa*, *Citronella paniculata, Weinmannia humilis*, *Ocotea porosa, Podocarpus sellowii* and *Drimys brasiliensis* are typical species in such areas (Leite & Klein, 1990; Roderjan, 1994, Koehler et

al., 2002; Roderjan et al., 2002; Pires et al., 2005; Scheer, 2010; Scheer et al., in press a).

Also called "Mixed Ombrophilous Forest" (IBGE, 1992), this forest physiognomy is characterized by merging elements from two distinct flora origins: the Tropical Afro-Brazilian and the Temperate Austro-Brazilian (Veloso et al., 1991). Classified as a Subtropical Forest, this ecosystem occurs mainly in the First and Second Plateaus of Paraná (mainly in the Center and the South of the state) at altitudes generally varying between 800 and 1000 m a.s.l. (Figure 1). In this region, temperatures are relatively low and frosts are common. In many locations, these formations share the landscape with natural grasslands.

are very common in the Montane belt (Schorn, 1992; Roderjan, 1994, Blum, 2006).

usually understated (Roderjan et al., 2002; Pires et al., 2005; Blum, 2006; 2010).

Roderjan et al., 2002; Pires et al., 2005; Blum, 2006).

**3.1.5 Upper Montane formation** 

**3.2 Araucaria Rainforest** 

This formation presents a continuous canopy (about 20-25 m height) and two physiognomies can be distinguished. *Calophyllum brasiliense* trees dominate the canopy of areas with soils subject to waterlogging (Histosols, Spodosols and Entisols). This species is generally associated with *Tabebuia cassinoides*, *Tapirira guianensis, Ficus luschnatiana*, *Ilex pseudobuxus*, *Clusia criuva* and *Pouteria beaurepairei*. In better-drained lands, non-hydromorphic Entisols (Quartzipsamments/Arenosols) and Spodosols support higher diversity. There are common in the canopy *Tapirira guianensis*, *Ocotea pulchella*, *Ficus organensis*, *Manilkara subcericea*, *Pera glabrata, Alchornea triplinervia*, *Andira anthelmia*, *Ilex theezans*, *Ternstroemia brasiliensis*, besides many Myrtaceae such as *Psidium cattleianum* and *Myrcia multiflora* (Leite & Klein, 1990; Silva, 1990; Jaster, 1995; Jaster, 2002; Roderjan et al., 2002; Pires et al., 2005).
