A VEGETATION OVERVIEW ON ROCKY OUTCROPS IN BRAZIL

Abstract

Rocky outcrops are isolated ecosystems inserted on a different surrounding landscape. They are refuges for endemic, geographic isolated and threatened species, and are also sources of new species. Occurring especially in arid climate, they are exploited in a disorderly manner and have been poorly studied in Brazil. Thus, the objectives of this review are (1) to diagnose the current level of knowledge about vascular and avascular flora in rocky outcrops, (2) to compare the number of studies published on this ecosystem before and after Scarano (2007)'s publication, and (3) to describe how these studies are distributed in Brazil according to the phytogeographic domains. Published studies were obtained from Portal de Periódicos CAPES/MEC, Scielo, and Academic Google databases, as well as from the search for citations in the selected articles. All articles involving rocky outcrops, regardless of the plant group studied and their mineral composition were selected. Articles were divided into two time periods, 1980-2007 (P1) and 2008-April/2016 (P2). Over the years, studies on outcrops vegetation have gained considerable attention: in P1 about 1.4 articles/year were published, while in P2, 4.8 articles/year. Nevertheless, these studies are concentrated mainly in the Floristic, important research line to subsidize studies on conservation and ecology. In P1, a larger amount of publications was observed for the Atlantic Forest domain, and in P2, for the Caatinga, where rocky outcrops are more abundant. Phanerogams were the most studied group, followed by bryophytes, ferns, and lycophytes. Still, in the current scenario, the knowledge about the flora of these ecosystems can be considered incipient, especially regarding conservation.