Grassland Vegetation of Pitangui River Valley, Southern Brazil

A systematic floristic survey was carried out on native g rasslands at Pitangui river valley areas, in the state of Paraná, Southern Brazil. Monthly samples collection covering an area of 9.4 ha over a two year period was conducted. A total of 51 angiosperm, one conifer and 4 fern families from four mesic steppic areas were identified. There were 196 genera and 420 species present in the area surveyed. The family Asteraceae contributed the highest species richness with a total of 119 species, 28% of the total. Herbs were found to dominate the area contributing almost 80% of all the plant forms. There were six non-native species, including African grasses and contaminating exotic pines observed and identified in the g rassland area. Twelve native species, belonging to 11 families (contributing a total of 2.8% of all the flo ra identified) are listed as threatened. The high species richness and the considerably high number of threatened species in such a small area underlined the need for more conservation efforts in these grasslands. It is therefore recommended that additional zoning and better management effort be the primary concerns to conserve the area.


Introduction
Native subtropical grasslands at South Brazil plateaus are located at high altitudes where low temperatures and high annual rainfall usually predominate. Riparian areas in Campos Gerais are co mbined by moderate to poorly drained soils, covered by hydrophilous steppes or by pioneering formations of fluvial influence, where Haplic Histosols, Melanic Gleysols, or Fluvic Leptosols can be encountered. In addition, hygrophilous to mesic steppes typically encompassing herbs and shrubs species, where Litholic Leptosols and Haplic Inceptisols are also available [1], [2].
The great ecological relevance of the Brazilian Atlantic Rainforest biome, which includes grasslands, has given this area the status as global biodivers ity hotspots [3], [4]. The remain ing grasslan ds in the stat e o f Paran á have been suffering severe anthropogenic pressure, especially due to the exp ans ion o f ag ricu ltu re and no n -n at ive fo rest ry activit ies. Ho wever, despite the global impo rtance of this grassland ecosystem, their floristic richness is hardly known. Therefore as one of the first steps of the Biodiversity of grassland-forest ecotones in South Brazil Pro ject team was to provide a species checklist of Pitangui river valley native grasslands. Their adaptive lifeforms were prev iously discussed by Mioduski & Moro [5].

Methods
We carried out this floristic study in the dip slope of 1 st cuesta of state of Paraná (Devonian Slope), inserted over Furnas sandstone, with med iu m alt itude of 980 m a.s.l. The area is co mprised of the region nationally known as Campos Gerais, specially where Pitangui river flows within a canyon in its mediu m curse crossing the Slope (J 594408 E 7232272), after Alagados dam, between Ponta Grossa and Carambeí municipalities, Paraná State ( Figure 1). The climate is Cfb (altitudinal subtropical humid) according to Köppen's classification, with mean annual temperature between 18 and 19°C, and an average rainfall o f 1,600mm/yr [6].
Sample collection was carried out monthly over a t wo year period (August 2009/July 2011) in an 9.4 ha area inserted over Furnas sandstone formation on superficial soils of 1 meter or less. According to the Brazilian Soil classification system, the Abrigo Pitangui site (A) is an 2.1 ha concave slope whith Haplic Camb issols, Litolic Neossols and Fluvic Neossols in sequence. The Usina São Jorge site (B) is an 0.2 ha flat surface with Haplic Camb issols, The Fazenda Panorama site (C) is an 4.0 ha slightly convex slope with Haplic Camb issols, and the Mirante Pitangui site (D) is an 3.1 ha slightly convex slope with Litolic Neossols. Botanical material was collected according to the wandering method described in Filgueiras et al. [7], that consists of listing the species presented in each delimited area as the investigator walks slowly on straight lines along it. Vouchers are deposited in the UEPG herbariu m (HUPG), and research has been authorized by SISBIO 28694/ 1. For species' taxonomic classification, Tryon and Tryon [8] and Smith et al. [9] for Ferns, and Angiosperm Phylogeny Group III [10] for Angiosperms were follo wed. The official plant names and their authors followed the electronic databases of Kew Gardens Plant List [11].
Evaluation and enumeration of the presence of extinction threatened species in the study area through comparison and review of Brazilian official threatened species lists [12], [13], [14] was also conducted. In addition, the presence of non-native plant (exotic) species was evaluated through revisions of the local governmental list [15] and Horus Institute [16].

Results and Discussion
Among the four areas, we recorded 421 taxa distributed in 51 Angiosperm families, one Conifer and 4 Ferns. There were present 420 species and 196 genera ( Table 1). One Aristida taxon (Poaceae) was identified only at the generic level at this mo ment, needing further studies to settle it as a new species.

Conclusions
The species richness of Pitangui river valley grassland was higher (420 species on 8.3 ha) co mpared to availab le data from Campos Gerais region, as listed from the Vila Velha and Guartelá State Parks which were made upon larger protected areas. Asteraceae, Fabaceae, Poaceae, and Cyperaceae are the main families in this ecosystem. The presence of non-native species (4 species), and invasive Pinus species (2 species), and the increasing nu mber of threatened species is alarming considering the location and the size of the area. Therefore, it is only high time to suggest that additional zoning and better management effort be the concern of the authorities to conserve the Campos Gerais National Park and its vicinities