Pteridófitas da Serra do Caparaó, Brasil: inventário e relações florísticas

Abstract

Mountainous environments are considered areas of remarkable importance for pteridophyte richness and endemism. The Serra do Caparaó mountain chain is an important region inserted in the Atlantic Forest domains of Minas Gerais and Espírito Santo states, Brazil. The area is characterized by a mosaic of grassland (campos de altitude) and forest (riparian forest, Tropical Rain Forest montane and cloud Forest) formations, with an average altitude of 2000 m, ranging from 960 m in the low areas, to the highest point at 2891 m, the Pico da Bandeira. The area is also inserted in one of the centers of pteridophytes diversity in the country, showing high species richness. The current study aimed to survey the pteridophyte community of the Serra do Caparaó, while investigating the floristic relations of the study site with other areas in the country. The survey was performed analyzing the voucher material available in regional herbaria (BHCB, CESJ, MBML, GFJP, HUEMG), besides field expeditions for data collection. The samples were collected and prepared according to the usual techniques adopted for pteridophytes, and deposited in the Herbaria from Universidade Federal de Minas Gerais. Taxonomic identification was based in specific literature, by comparisons with previously identified samples, and according to specialists review. Floristic similarity/relations between sampled areas were assessed using grouping method, Sørensen coefficient of similarity, and ordinance technique nonmetric multidimensional scaling. A total of 292 pteridophyte species were registered for Serra do Caparaó, distributed among 22 families and 76 genuses. The most representative genus was Thelypteris (32 species), followed by Elaphoglossum (26), Asplenium (20), Blechnum (16) and Huperzia (13), with 37 % of the genuses holding from one to four species. The majority of the registered species were exclusively terrestrial (38,7%), and, most of the species (61,3%) showed a single habit type. A monotonic-declining pattern was observed for the epiphytic habit when compared to the altitude, and, according to the results of a linear regression analysis, the epiphytic habit was inversely correlated with an altitudinal increasing. The floristic relations suggests that pteridophytes species distribution pattern is mostly influenced by edaphics factors, however, geographic distance also contributes to influence the distribution, regarding the strong correlation reported for areas showing the same phytophysiognomie. Detailed taxonomic identification keys and genus/species diagnose are provided, together with comments, description of the environment for each collection site, geographic distribution, description of the sampled material and list of occurring species in the study site.