Floristic diversity and reproductive phenology in phytophysiognomies of Pousada das Araras Reserve, municipality of Serranópolis, State of Goiás, Brazilian Central Plateau

Abstract

This work was carried out in Pousada das Araras Reserve (51º59’42”-52º00’22”W; 18º26’33”-10”S) in the municipality of Serranópolis, state of Goiás, in the core area of the Cerrado, Brazilian Central Plateau, aiming at studying the richness and diversity of species in plant formations and analyze their  phenological reproductive patterns. Data were collected from May 2004 to June 2006. The phytophysiognomy units were  identified using aerial images, global positioning system (GPS), and visual observation of ecological aspects. Fertile plant samples were collected in the usual way, numbered, dried and pressed, sorted, identified, and deposited in the  Herbarium Jataiense Germano Guarim Neto (HJ). The taxa
were identified according to APGII and the species were  assembled in the herbaceous-sub shrub (chamaephytes, geophytes, hemicriptophytes, lianas, therophytes,  hemiparasites, epiphytes) and shrub-arboreal (phanerophytes) components. As to phenological data, we registered the species that were flowering (blossom/anthesis) and fruiting (mature/
immature fruit) in each phytophysiognomy. We analyzed 3,120 registers and used descriptive statistics, qui-square test,  Kolmogorov-Smirnov test, parametric circular statistics, Pearson’s correlation, and Rayleigh test. The reserve presented 101 families, 325 genera, and 554 species, distributed in seven phytophysiognomies, with high diversity and  heterogeneity (H’ = 0.78; J = 0.94). The families presenting the highest floristic richness were: Fabaceae, Rubiaceae, Asteraceae, Myrtaceae, Poaceae, Apocynaceae, Cyperaceae, Euphorbiaceae, and Bignoniaceae. The typical Cerrado  presented 70% of the families, 50% of the species, among  which 12% were exclusive species. The humid field presented 8% of exclusive families. The relationship between  shrub/arboreal and subshrub/ herbaceous components richness was 1:1,5. Flowering proved to be seasonal only in field phytophysiognomy (p ≤ 0.05), and fruiting was seasonal in the Cerrado (p ≤ 0.05) and field phytophysiognomies (p = 0.05). This work evidenced phanerogamic richness as well as heterogeneity of species and environments, pointing out the representativeness of the assessed reserve regarding the Cerrado flora. The sub-shrub/herbaceous component proved to be richer, but both components present a phenological pattern in which the shrub/arboreal species converge their reproduction to the end of the dry season/beginning of the rainy season and the sub-shrub/herbaceous species, to the end of the rainy season/ beginning of the dry season, evidencing a pulse in the communities. This study contributed to the knowledge on the flora and phenological reproductive patterns in the Cerrado in the Brazilian Central Plateau, whose ecological aspects are not well known. We should point out the need to implant projects that seek for the conservation of the studied reserve.