**3.2 Araucaria Rainforest**

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.

Arboreal Diversity of the Atlantic Forest

in Godoy State Park.

this forest type.

**3.3.1 Alluvial formation** 

and Gleysols (Roderjan et al., 2002).

**3.3.2 Submontane formation** 

textures and fertility levels can be found in these soils.

**3.3 Semideciduous Seasonal Forest** 

200 and 600 m a.s.l. (Roderjan et al., 2002).

of Southern Brazil: From the Beach Ridges to the Paraná River 117

The Semideciduous Seasonal Forest region in the the state of Paraná occurs mainly in the Third Plateau (almost the entire North and West of the state) in altitudes generally between

According to the Köppen system, the climate can be classified as Cfa, or meso-thermic, wet. Daily mean temperatures in the coldest month are under 18 ºC and the mean temperature of the warmest month is over 22 ºC (Maack, 2002). However, in this ecosystem the year can be divided into two distinct seasons: one tropical with intense summer rainfalls and short dry periods, and another subtropical with low winter temperatures and scarce precipitation. During this unfavorable cold and dry period, between 20 and 50% of the canopy trees are deciduous (Veloso et al., 1991; IBGE, 1992). In very specific locations this forest has as ingrown ecosystem the Savanna (Cerrado), which reaches its austral limit in this specified

The Semideciduous Seasonal Forest shows succinct variations ranging from the evergreen to deciduous trees, which reach heights close to 30-40 m without forming a continuous superior canopy. This feature allows a great deal of sunlight to reach the forest ground, turning possible the development of a vigorous lower stratum (Silva & Soares Silva, 2000). There are also shrubs, lianas and epiphytes, although in lower abundance and richness compared to rainforests (Leite et al., 1986; Lamprecht, 1990; Leite & Klein, 1990; Roderjan et al., 2002). A compiled list of the tree flora of the Semideciduous Seasonal Forest of Southern Brazil, using data of the botanical collection of the Barbosa Rodrigues Herbaria, presents at least 213 tree species (Leite & Klein, 1990). Silva & Soares Silva (2000), found 206 arboreal species

Satellite images taken in 1998, indicate that 4174.7 km2 of Semideciduous Seasonal Forest communities at intermediate or advanced stages of succession covered only 5.4% of the original area of distribution in that year (SEMA, 2002). Some forests of the northern region were reduced to less than 1% in Maringá and 0.8% in Assaí municipalities (IPARDES, 1986). Forward are presented the characterizations for the Alluvial and Submontane formations of

This formation is distributed over riverine floodplains and some islands in the Paraná river, and also around some of its tributaries. The Alluvial formation occurs predominantly in soils with considerable hydromorphy, such as some Fluvisols, Entisols (Quartzipsamments)

The Alluvial Semideciduous Seasonal Forest is characterized by a canopy about 15 to 20 m height and lower floristic diversity. Among the main species are *Cecropia pachystachya*, *Triplaris americana*, *Calophyllum brasiliense, Gallesia integrifolia* and *Chrysophyllum gonocarpum. Sebastiania commersoniana*, *Anadenanthera colubrina, Acrocomia aculeata* and *Inga uruguensis* are also common

In the state of Paraná, this formation can be found under 600 m a.s.l.. The Submontane Semideciduous Seasonal Forest occurs in soils of different lithologies (sandstone and igneous extrusive rocks) that result in Oxisols, Ultisols, Regosols (Psamments), Inceptisols, Leptosols and Arenosols (Roderjan et al., 2002). Depending on the lithology, different

(Leite et al. 1986; IBGE, 1992, Roderjan et al., 2002; SEMA, 2002; Costa Filho et al., 2006).

region, covering otherwise a major part of Brazil's Mid-West (Figure 1).

According to Köppen System, the climate of the Araucaria Rainforest region is Cfb, with annual average temperatures between 16 and 18 ºC and average annual rainfall generally between 1400 and 1600 mm (Caviglione et al., 2000).

This forest formation shows structural variations related to environmental diversification, varying from dense formations with trees of ca. 25 to 35 m tall, to stunted formations consisting of variable density of trees and shrubs, associated with terrestrial ferns and bamboos (Leite & Klein, 1990). According to Maack (2002), *Araucaria angustifolia*, commonly known as the "Brazilian pine" or "Paraná pine" is the dominant tree of this region, distinguishing this landscape.

A compiled list of the Araucaria Rainforest tree flora of Southern Brazil, using data of the botanical collection of the Barbosa Rodrigues Herbaria, revealed 352 species. Almost 50% of those species occur exclusively in this type of Atlantic Forest (Leite & Klein, 1990).

Castella & Britez (2004) analyzed satellite images from 1998 and concluded that Araucaria Rainforest communities at intermediate or advanced succession stages still covered 13420.6 km2 of the state of Paraná, representing about 16.2% of the original cover (Castella & Britez, 2004). However, primary remnants are much less representative.

Two formations are presented in this section: Alluvial and Montane Araucaria Rainforests.
