Flora vascular relacionada aos afloramentos de rocha carbonática no interior do Brasil

Abstract

In any Brazilian bioma, the occurrence of carbonatic rocks delimitates a particular feature, the karste, which, through the specific geomorphology and hidrology differs from the landscape domains. The Karstic landscape is also characterized by the green cover, composed of a phytophysiognomic mosaic, which parts – forested areas and one open saxicola phytophysiognomy – is distributed in the landscape according to a delicate combination of local factors, among them is highlighted the degree of denudation of the rock. The Karste feature offers local contrasts and phytophysiognomic similarities between regions geographically distal in function of specificity of its topographic features. Through the analysis of rock samples it was verified, in some places, different kinds of carbonatic rocks – calcarium and dolomite – compose the same residual massive, fact which can influence the local floristic composition. It is necessary to approach different scales of geographical scope – local, regional and biomas – to analyze the distribution of the flora related to the Karstic feature. Floristic surveys were made during the last five years in areas of carbonatic rocks flourishments in the states of Bahia, Goiás and Minas Gerais, specially in the region of Mata de Pains-MG, revealed a considerable vegetal richness related to the Karstic environment, mainly herbaceous vegetable species. 839 species were found or morphospecies of vascular plants distributed into 95 families and 414 genres. Large broaden geographic distribution species took part in the floristic composition of the studied area. There were scaling influences of the floristic nucleus Caatinga and Floresta Atlântica ( Atlantic Forest). It was observed species with apparent affinity for the carbonatic rocks flourishments, some of large geographical distribution, others restrained into a determined Karste or bioma, suggesting endemism. It was verified a great difficulty in the detection of conspicuous species, in a geophyte and terophyte way of life, due to the climatic seasonality. Flourishments of carbonatic rocks are speciation places and vegetal diversity reservoirs, xeric and wet which presents floristic heterogeneity in different scale of analysis - local, regional and biomas. It is urgent the need of creating unities for total protection conservation in Karstic areas in all the biomas. In the group of sustainable conservation unities, it is highlighted the categories of Ecological Relevant Interest Area and Private Reserve of the Natural Patrimony. The first for embracing general areas of small extension, with little or none human occupation, several times with the extraordinary natural characteristics for lodging rare species of the National Biota. The creation of the RPPN represents a consistent environmental compensation for mining entrepreneurs, once the extraction of the rock causes a complete destruction of the Karstic micro-environment. Therefore it is suggested that each mining enterprise create at least one RPPN in the same region of the exploited area, once each Karstic region studied presented particular floristic composition.