Diversidade e biologia reprodutiva de briófitas em campinaranas e florestas de terra firme de sítio amostral na Amazônia Central

Abstract

The Amazonian region is the world’s biggest rainforest, harboring different types of vegetation such as Terra Firme forests and Campinaranas, in which many bryophytes species are also found. In Central Amazonia, bryophytes have been investigated from a floristic and ecological point of view, especially in Terra Firme forests, where they are rarely related to the vertical gradient or their reproductive strategies. Thus, this study aimed to analyze the composition, richness, and reproductive strategies of bryophytes in Campinaranas and Terra Firme forests in the Uatumã Sustainable Development Reserve (USDR). In this background, transects of 50 m were installed in each vegetation and the collections were carried out both in the vertical gradient (three height zones of phorophytes (trees) from the trunk base, bifurcation up to outer canopy) and in the horizontal gradient (substrates in the understory) in Campinaranas (shrubby, arboreous and forested) and Terra Firme forests (plateau, slope, and valley) in the USDR. In addition, for the writing of chapter 1, samples collected by the research group along the Uaupés River, in the municipality of São Gabriel da Cachoeira, in Amazonas, were also analyzed. Regarding the species composition of bryophytes in the Amazonian Campinaranas, an updated species list and new records for the state of Amazonas were provided. About the richness, composition, and spatial distribution of bryophytes, a total of 123 species were identified in the vertical and horizontal gradients of Campinaranas and Terra Firme forests. The liverworts represented 70% of the total species identified. Furthermore, the influence of the vegetation on the bryophytes composition was verified, with a high quantity of exclusive species in each environment and greater species richness occurring at the base or top of the trees in Campinaranas and Terra Firme forests, respectively. The results about the reproductive strategies of bryophytes along the vertical gradient showed a high frequency of reproduction among species, a predominance of monoecious species in the samples, as well as among species with reproduction, a predominance of sexual reproduction among species, low production of sporophytes in mosses and a predominance of female species among dioecious species. Finally, this study is pioneering and describes the structure of bryophyte assemblages and their reproductive aspects in Campinaranas environments and increases the knowledge of bryophytes in the vertical gradient on Terra Firme forest in Central Amazonia. Thus, it contributes to filling part of the gap about this group in Amazonian environments and can assist in decision-making in preservation, management, and conservation actions to mitigate possible biodiversity losses.