On-line version ISSN 1676-0603
LATANSIO-AIDAR, Sabrina Ribeiro; OLIVEIRA, Ana Claudia Pereira de; ROCHA, Humberto Ribeiro da and AIDAR, Marcos Pereira Marinho. Phytossociology of a dense Cerrado on the footprint of a carbon flux tower, Pé-de-Gigante, Vassununga State Park, SP. Biota Neotrop. [online]. 2010, vol.10, n.1, pp. 195-207. ISSN 1676-0603. http://dx.doi.org/10.1590/S1676-06032010000100020.
The Cerrado vegetation covers the Brazilian central areas (core area) which include extensive and continuous areas in the central States and some marginal areas in other States, including São Paulo, accounting originally for 21% of Brazilian territory. Nowadays, the remnants are 21,6% of its original coverage. About of 14% of the São Paulo State territory was originally covered with Cerrado vegetation, and today remnants account for less than 1% of the original distribution. Recent studies indicate that the net productivity in the Pé-de-Gigante Cerrado constitutes a small carbon sink, with seasonality playing a major role. The carbon flux studies in terrestrial ecosystems have rarely been accompanied by ecophysiological studies in order to explore the functional relationships among species, ecosystem and the values achieved. Therefore, our objectives were to characterize the vegetation structure in the meteorological and flux tower footprint. The flux tower allows studies related to long term measurements and dynamics of water, solar energy and CO2 fluxes in Cerrado vegetation. Plots (10 x 10 m) were established in 0.2 ha area of Cerrado and all vascular plants with stem perimeter at ground level >6 cm (except vines and dead individuals) were sampled. The distribution of diameter classes and vertical structure, as well as the phytosociological parameters were analyzed. We recorded 1,451 individuals, distributed in 85 species belonging to 31 different families. The absolute density and the basal area were 7,255 ind.ha-1 and 7.9 m2.ha-1, respectively. Leguminosae showed the highest number of species (13). The Shannon's Index was 3.27. The distribution of diameter classes showed a curve in inverted "J", most of the individuals being in the initial classes. We concluded that the area must be classified as dense Cerrado, mainly due to Anadenanthera falcata dominance, which occurrence in São Paulo State was reported only in rich soil sites in Cuestas Basaltic regions and also due to major basal area of these individuals, comparing with other Cerrado vegetation sites. A. falcata, Myrcia lingua and Xylopia aromatica showed the highest IVI (Importance value index).
Keywords : Anadenanthera falcata; basal area; Basaltic Cuestas; importance value index; Leguminosae; Santa Rita do Passa Quatro.