Distribuição de musgos (Bryophyta) no Brasil: riqueza, endemismo e conservação

Abstract

Bryophyta (mosses) are the second most diverse division of terrestrial plants, with about 13.000 species. In order to compile the knowledge of the bryophyte flora for Brazil, a range of studies were developed showing the States with the largest number of species and evidencing the lack of sampling for the country. However, the deficiency in the knowledge of mosses in Brazil is not yet known precisely. One of the main themes in biogeography is to understand why species are widely distributed or endemic. Endemism is related to the restricted occurrence of, because they originated in this place and did not disperse, or because they were confined to the area, in relation to its previous distribution. Two allopatric hypotheses are most relevant for diversification models: Pleistocene Refuge and Montane Isolate Hypothesis. In Brazil, the preserved areas are protected through Conservation Units (UCs), which have low degradation traits, making it an excellent habitat for the colonization of bryophytes. Thus, the main aims of this work were to study the distribution of mosses in Brazil, identifying the richness and endemism in the country and to present a conservationist approach to mosses species. Firstly, in order to compile information on the occurrence of mosses, we did a survey of the data through different online databases and bibliography. Subsequently, we refined these data regarding the identification at the specific level, the taxonomic validity and the geographic coordinate. Then, we marked the points of the records on the map, and we elaborated the grids by squares of 1° x 1°. Therefore, we performed analyzes of richness, estimated richness, number of records and the Parsimony Analysis of Endemicity (PAE). We used the species distribution predictive modelling to corroborate the existence of areas of endemism in Brazil and to elaborate a map of endemism clustering areas. Of the total, we collected 868 species of mosses from 26.691 records. From this information, we filled a number of 394 squares, having the number of species per grid ranging from 1 to 235. The Atlantic Forest presented greater richness, both by the conditions that it provides to the establishment of moss, and the greater sampling intensity in the Domain. The PAE resulted in only one area of endemism, located in the center of the State of Bahia, in the Phytogeographical Domain of the Caatinga, in the region of the Parque Nacional da Chapada Diamantina. The grids proposed as potential areas of endemism were found in six areas, scattered in the Cerrado and in the Atlantic Forest. The areas of endemism of mosses are mostly areas of mountains, which corroborate the main hypotheses of speciation of the organisms. In the UCs, 218 showed areas with environmental suitability for the presence of the species, whereupon 68 are inserted in the categories of Sustainable use and 150 in the category of integral protection, demonstrating the importance of the UCs for the bryoflora in the Atlantic Forest.