Biodivers Conserv (2007) 16:1699–1714 DOI 10.1007/s10531-006-9044-7 ORIGINAL PAPER Woody plant species richness in the Turvo State park, a large remnant of deciduous Atlantic forest, Brazil Ademir R. Ruschel Æ Rubens O. Nodari Æ Bruno M. Moerschbacher Received: 13 September 2005 / Accepted: 22 March 2006 / Published online: 22 May 2006 Ó Springer Science+Business Media B.V. 2006 Abstract This paper presents a quantitative inventory of woody plants with DBH ‡ 5 cm in Turvo State park, a large remnant (17,500 ha) of seasonal deciduous Atlantic forest in Southern Brazil. The forest inventory was based on 141 sampling points (point centered quarter method). Seventy-eight species from 37 families were recorded, the density was 879 plants ha–1 and the basal area 25.12 m2 ha–1. Timber species of commercial value made up 35% of the species and 72% of the basal area. The ten most abundant species made up 52% of the species, and the ten species with highest basal area accounted for 48% of the total basal area and 12% of the species. Zoochory was the dominant mode of seed dispersal, representing 63% of species and 67% of the plant density. Nine percent of the species were pioneers, 56% were secondary species accounting for 62% of the total basal area, and 35% were opportunistic-climax species accounting for 54% of the plant density. Turvo park has exceptionally high biodiversity and is the last intact large remnant of the Alto- Uruguai river ecosystem. In addition to species richness and an abundance of high value timber species, this forest is of value for the rich genetic resources, and for medicinal and ornamental plants. Keywords Ecological groups Æ Endemic species Æ Floristic composition Æ Seed dispersion Æ Timber species A. R. Ruschel (&) Æ R. O. Nodari Departmento de Fitotecnia, Universidade Federal de Santa Catarina, Caixa Postal 476, Floriano´ polis CEP 88040-900 SC, Brazil e-mail: [email protected] B. M. Moerschbacher Department of Plant Biochemistry and Biotechnology, Westphalian Wilhelm’s University of Mu¨ nster, Mu¨ nster, Germany 123 1700 Biodivers Conserv (2007) 16:1699–1714 Introduction Subtropical Atlantic Forest, also named Seasonal Deciduous Forest, represents a small ecosystem in the basin of the Uruguai river in Southern Brazil (IBGB 1990). The primary forest of that ecosystem is characterized by a closed canopy dominated by Lauraceae and emergents of Fabales species. These emerging trees are responsible for the typical appearance of the forest, more spectacular in summer due to the abundant blossoming of the dense treetops, and less obvious during winter when they shed their leaves. The subcanopy is dominated by Sorocea bonplandii, Gynnanthes concolor, and Trichilia species, and epiphytes are very poor when compared with the tropical Atlantic forest (Rambo 1956). Besides harboring a rich flora, the region is also shelter for endangered animal species (Wallauer and Albuquerque 1986). The economic development of the Alto-Uruguai river region was initially based on the exploitation of the noble timber species by the lumber companies or by the colonists themselves (Ruschel et al. 2003). As a consequence, in a short period of time, the exuberant forest originally encompassing an area of 47,000 km2 was re- duced to less than 2,000 km2. Most of this remaining forest occurs near the Uruguai river in the border region between Brazil and Argentina (Google Earth 2005). Turvo park is the largest undisturbed remnant of Subtropical Atlantic Forest ecosystem preserved in Brazil. Some small fragments of this forest have survived in small areas with prominent relief or high slopes in the west of Santa Catarina State, but not even a single public domain area is under legal protection in this state. Thus, the Subtropical Atlantic Forest is the most threatened forest ecosystem in South Brazil today. Previous studies of the native flora in the Alto-Uruguai river basin reported high species richness of timber value, and new species to this ecosystem have been identified in each new study (Rambo 1956; Klein 1972; Brack et al. 1985; Dias et al. 1992; Cristo´ bal and Vera 1999; Davin˜ a et al. 1999; Ruschel et al. 2003). Rambo (1956) reported that epiphytes are almost completely lacking in Subtropical Atlantic Forest, but in a small remnant of this ecosystem, Rogalski and Zanin (2003) found 70 epiphytes species belonging to 30 genera and eight families. Little quantitative data on the abundance and dominance of the species of these forests is available, and almost none for primary forest. Knowledge on the species in primary forest are important as a reference for studies of forest fragmentation effects, and for defining guide lines for sustainable management and protection of this ecosystem. The aim of the current study, thus, was to further analyse the floristic, phytosociological, and ecological structure of the shrub and arboreal species in Turvo park. Methods Study site Turvo park, encompassing an area of 17,500 ha of Subtropical Atlantic Forest, is located in the extreme northwestern section of the southern Brazilian state Rio Grande do Sul (Fig. 1). Its western border is marked by the Uruguai river, and it is complemented by the Mocona´ park west of the river, in the Argentinian province of Misiones. Turvo park, created in 1947, represents one of few remnants of seasonal deciduous forest of the Uruguai river ecosystem, and it is in many ways similar to the 123 Biodivers Conserv (2007) 16:1699–1714 1701 Fig. 1 Map of the study area, Turvo park, in Southern Brazil. On the other side of Uruguai river, Turvo park is complemented by Mocona´ Park in the Argentinian state Misiones (adapted from Google Earth 2005) Iguac¸u´ national park, in Parana´-Brazil. According to Rambo (1956) and Klein (1972), the subtropical forest of Alto-Uruguai is an extension of the forest of the Parana´ river, through the province of Misiones. The area of Turvo park reaches altitudes between 200 and 400 m above the sea level. The soil consists of extrusive rocks of basaltic origin, forming an eutrophic red soil, in a hilly relief. The annual average temperature is 18–20°C, with the lowest temperatures in July and the highest in January. Frosts regularly occur between June and August. The annual precipitation (2200–2400 mm) is well distributed, occurring on 80–100 days per year, with a precipitation deficit towards the end of spring and the beginning of summer (IBGE 1990). Sampling method The present study was carried out in areas of primary forest during the month of February, 2002. Forest inventories were compiled using the point-centered quarter method (Cottam and Curtis 1956). Three areas were chosen, between 27°11¢24¢¢ to 27°12¢34¢¢ S and 53°51¢03¢¢ to 53°51¢33¢¢ W, at altitude of 290–350 m above the sea level. The sample areas were situated 6.5, 9.0 and 11.5 km from the north-eastern border of the park (Fig. 1). The point-centered quarter method was considered efficient and suitable for floristic inventories in temperate and tropical rain forests, being advantageous in terms of time and costs when compared with the quadrate plots method (Cottam and Curtis 1956; Gibbs et al. 1980; Cavassan et al. 1984; Krebs 1989; Dias et al. 1992; Sparks et al. 2002). According to these studies, sample size is more important for precision in forest inventories than the sampling method used. 123 1702 Biodivers Conserv (2007) 16:1699–1714 In each area, a straight line with a length of 750 m pointing south was marked with sampling points 15 m apart. In each of the quarters defined by a sampling point, the closest living plant (with the exception of lianas) with a DBH ‡ 5 cm (diameter at breast height = 1.3 m) was identified taxonomically, and DBH and total height were taken. Thus, a total of 141 sampling points yielded 564 plants. The classification of the species was performed with assistance of bibliography (Reitz and Klein 1964; Reitz et al. 1978; Lorenzi 1998) and with the help of taxonomists Prof. Marcos Sobral (Federal university of Rio Grande do Sul) and Prof. Ademir Reis (Federal university of Santa Catarina). In the case of plants with more than one living trunk, all trunks with DBH ‡ 5 cm were evaluated. Whenever possible, total height was measured using a forest measure ruler or a clinometer. According to Krebs (1989) the quantitative sampling error was estimated based on the distances of the classified trees from the sampling points, and the qualitative sampling sufficiency was esti- mated by the species area curves (Fig. 2). The phytosociological parameters basal area, density, and dominance, the index of diversity H¢ of Shannon and Wiener and the evenness index were determined according to Krebs (1989). Ecological structure Species were classified in three groups: (i) Pioneers, the first forest species appearing in the forest succession; (ii) Secondary species, succeeding the previous group and needing greater soil fertility, shade levels, and humidity; and (iii) Climax/Opportu- nists, only occurring in advanced stages of succession when the edaphic conditions (shade, humidity, and fertility) are suitable and agents for their pollination and seed dispersal are present. Species were also classified according to their method of seed dispersal in three categories: anemochoric; autochoric; and zoochoric (Janson 1983). In the absence of detailed studies for a given species, the classification was based on published information (Tabarelli 1992; Dalling et al. 1998; Nascimento et al. 2000; Traveset et al. 2001). Fig. 2 Species-area curves for the three sampling lines in Turvo park as well as the cumulative species-area curve for all three sampling lines. Woody plants with a DBH ‡ 5 cm were identified using the point-centered quarter method 123 Biodivers Conserv (2007) 16:1699–1714 1703 Results Species diversity, density and dominance Using the point-centered quarter method, 564 plants were identified along three lines each of about 750 m total length, in the center of Turvo park.