**3. Atlantic Forest Biome, environmental and vegetational features**

The Atlantic Forest in the state of Paraná has three distinct types of forest ecosystems: the Dense Rainforest (Atlantic "Ombrophilous" Dense Forest), the Araucaria Rainforest (Mixed "Ombrophilous" Forest) and the Semideciduous Seasonal Forest (IBGE, 1992). Each one of these forests also comprises distinct formations and associated or ingrown ecosystems, resulting from geomorphological and climatological features (Figure 1). The five main categories of formations (IBGE, 1992) were included, namely: Lowland (Coastal Plain Forest), Alluvial (Floodplain Forest), Submontane and Montane (both can be also considered Lower Montane), and Upper Montane. The Dense Rainforest presents all of these categories, whilst the Araucaria Rainforest and the Semideciduous Seasonal Forest Comprise mainly the Alluvial and Montane and the Alluvial and Submontane formations, respectively.

Besides presenting a brief literature review, this study compiles abundance data and updated floristic information from the most representative tree phytosociological studies of the Atlantic Forest formations in the state of Paraná, Southern Brazil. The data were obtained from scientific papers, doctoral thesis, master dissertations and from our own surveys performed for at least 10 years in the region (Table 1). The floristic information from

There was a difficulty in finding studies with same inclusion criteria (same diameter at breast height – DBH) for different formations. The minimum DBH value available in the original dataset ranged from 3.1 to 10.0 cm. This range was therefore considered in the present study.

The altitudes of the sites range from 5 to 1750 m a.s.l. The most distant sites (separated by 590 km) are located in the following geographic coordinates: 25°23' S; 48°13' W, near the

Sites in early and middle sucessional stages, as well as undetermined *taxa* and exotic species were not included. *Taxa* identified only to the family or genus level were grouped according to taxonomic hierarchy. For example: the Myrtaceae group included many undetermined *taxa* of this family, and the *Lonchocarpus* group comprised undetermined species of this genus. For the richness estimation, each taxonomic group of undetermined *taxa* was considered as a unique species. The data underwent a detailed review to check all accepted species names and synonymy according to the "Species List of the Brazilian Flora" (Forzza et al., 2010). The compilation of the surveys on forest structure comprised 29 hectares of sampled area and 36627 measured individuals. The diversity indexes were calculated according to Magurran (1988). Canonical correspondence analyses (CCA) processed by the program CANOCO 4.5 (Ter Braak & Smilauer, 2002) were used to assess the relationship between abundance of the tree species of 58 sites comprising nine Atlantic Forest formations, and geo-climatic variables. The matrix with abundances per forest site includes 631 species. The geo-climatic matrix includes the following variables: distance from the ocean, annual temperature, altitude and annual rainfall. Data not presented in the original studies were obtained from climatic maps of IAPAR (Caviglione et al., 2000). Major approximations of mean annual temperatures (decrease of 0.54 ºC for every 100 m of increased altitude) were used following recommendations in Roderjan & Grodski (1999). The Brazilian official vegetation classification (Veloso et al., 1991; IBGE, 1992) was used to

39 studies encompassing 58 forest sites was included in the present study.

Additionally, the different sample sizes were not standardized among surveys.

Atlantic Ocean and 22°43' S; 53°18' W, near the Upper Paraná River (Figure 1).

group the sites into each Atlantic Forest formation (see below).

**3. Atlantic Forest Biome, environmental and vegetational features** 

The Atlantic Forest in the state of Paraná has three distinct types of forest ecosystems: the Dense Rainforest (Atlantic "Ombrophilous" Dense Forest), the Araucaria Rainforest (Mixed "Ombrophilous" Forest) and the Semideciduous Seasonal Forest (IBGE, 1992). Each one of these forests also comprises distinct formations and associated or ingrown ecosystems, resulting from geomorphological and climatological features (Figure 1). The five main categories of formations (IBGE, 1992) were included, namely: Lowland (Coastal Plain Forest), Alluvial (Floodplain Forest), Submontane and Montane (both can be also considered Lower Montane), and Upper Montane. The Dense Rainforest presents all of these categories, whilst the Araucaria Rainforest and the Semideciduous Seasonal Forest Comprise mainly the Alluvial and Montane and the Alluvial and Submontane formations, respectively.

**2. Data analysis** 


Table 1. List of the analyzed fores sites in Atlantic Forest formations in the state of Paraná, Brazil. (N - site number used in this study; DRF – Dense Rainforest; ARF – Araucaria Rainforest; SSF – Semidecidual Seasonal Forest).

Arboreal Diversity of the Atlantic Forest

**3.1 Dense Rainforest** 

(Pires et al., 2005).

**3.1.1 Lowland formation** 

of Southern Brazil: From the Beach Ridges to the Paraná River 113

The Dense Rainforest, or Atlantic Forest *sensu stricto* (Oliveira-Filho & Fontes, 2000), is characterized by the dominance of large trees (25-30 m height) associated with many other biological forms, mainly epiphytes and woody lianas, that gives it its tropical appearance (Klein, 1979). Evergreen trees dominate the dense canopy (Veloso et al., 1991; IBGE, 1992). Different plant communities of this forest type are found from the beach ridges near the Atlantic Ocean to the upper montane ridges of the Serra do Mar (Sea Mountain Range) and its western slopes towards the ecotone with Araucaria Rainforest (Figure 1). The altitudinal gradient ranges from 1 to 1887 m a.s.l., resulting in this region in a decrease of 0.54 °C for every 100 m increase in altitude (Roderjan & Grodski, 1999). While the coastal plain formations are in soils derived from Cenozoic (mainly Quaternary) marine sediments, alkali granites, embedded in high-grade metamorphic terrains, form the mineral soil horizons of the upper portions of the landscape. According to Mineropar (2001), intrusive igneous rocks from Serra do Mar were originated nearly 550 million years ago in the Upper Proterozoic to Cambrian. Faults from the Brasiliano (or Pan African) Cycle (events of the end of the late Proterozoic) and the Ponta Grossa Arch, cut the landscape in the NE-SW and NW-SE axes, respectively. Therefore, the soils of the Dense Rainforest have a high variety in parent

material, genesis, depth, horizons, layers, structure, texture and organic matter.

of those species occur exclusively in this type of Atlantic Forest (Leite & Klein, 1990).

Forward we present the five cattegories of the Atlantic Rainforest.

1991; IBGE, 1992; Roderjan et al., 2002; Pires et al., 2005).

Dense Rainforest communities in the advanced stages of succession cover an area of 3937.5 km2 or 51,5% of the original distribution area as interpreted from satellite images from 1999

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.,

The climate of the lower portions of the Dense Rainforest gradient, up to the transition between the Submontane and Montane formations, 600 - 800 m a.s.l. (Blum, 2010), can be classified as Cfa, or meso-thermic, according to the Köppen classification system. Daily mean annual temperature is 21 ºC, the mean temperature in the coldest month is about 16 ºC and, in the warmest month is higher than 22 ºC, with hot and wet summers (December-March), and a no-pronounced dry season. Maack (2002) considered the region as having a transitional tropical climate (Af). The climate of upper portions, above 700 m a.s.l., is classified as Cfb (humid subtropical, meso-thermic, with cool summers, frequent frosts and no pronounced dry season). The mean temperature of the coldest month (July) in the region is less than 16 ºC (reaching 12.5 ºC) and of the warmest month (February) is less than 22 ºC (20.5 ºC). Measurements in the coastal region exceed 2000 mm of rain per year, and on the slopes of the mountains these values reach 3500 mm of rain per year (Caviglione et al., 2000; Maack, 2002). As a result of the high environmental variety the Dense Rainforest is the most heterogeneous, complex and rich forest ecosystem of Southern Brazil (Leite & Klein, 1990). A compiled list of the tree flora of the Dense Rainforest of Southern Brazil, using data of the botanical collection of the Barbosa Rodrigues Herbaria, revealed 708 species. More than 50%

Adapted from: MMA (2011) and Roderjan et al. (2002).

Fig. 1. Location of the 58 sites in the Atlantic Forest types in the state of Paraná, Southern Brazil. Numbers are related to sites presented in Table 1.
