Briófitas do baixo Tocantins, Pará, Brasil: diversidade em diferentes tipos de ambientes e a influência do tipo de restauração em áreas de terra firme no município de Abaetetuba.

Abstract

The Baixo Tocantins has a heterogeneous set of environments, of which the terra firme forests, várzea and praia de água doce stand out for their economic and ecological importance. The flora of these environments is rich and diverse, however there are still gaps about its composition in Baixo Tocantins, mainly about the flora of bryophytes. Of these environments, terra firme forests are the ones with the greatest history of deforestation in the region. Activities such as logging and traditional agriculture have contributed to the formation of secondary forests, under the influence of passive and active restoration processes. The aim of this study was to investigate the richness and composition of bryophytes in different types of environments and the influence of the type of restoration in terra firme areas in the municipality of Abaetetuba, Baixo Tocantins, Pará, Brazil. For this, biostatistical tools were used, such as hierarchical clustering and multivariate ordering analyses. The dissertation is divided into two chapters. The first chapter deals with the diversity and composition of bryophyte species in different types of environments in Baixo Tocantins, comparing with the same parameters with similar areas in the state of Pará. In total, 67 species of liverworts and 36 species of mosses were recorded. Through this study, one species was a new record for the state of Pará and a new record for South America. In this chapter, greater diversity was pointed out in the forest of Terra Firme, followed by the forest of Várzea and Praia de Água Doce. This difference may be related to the conditions of the available phorophytes and the characteristic of each type of vegetation. The floristic similarity between the vegetation and other areas of Pará showed that the Portel-Marajó Hydrographic region presented a distinct set of species from the forests of Terra Firme and Várzea. The vegetation of Praia de Água Doce contributed to the knowledge of liverwort, which in the past had not been inventoried. The second chapter aimed to test whether the type of restoration influences the restoration of the bryophyte community in terra firme forests in the Baixo Tocantins region, providing subsidies for the restoration and conservation of flora diversity in the Amazon. This study demonstrated that the floristic composition was the variable that most contributed to understanding the distribution of bryophytes along the stages. Sun-tolerant species prevailed in forests with active restoration, while shade-tolerant species were more represented in areas with passive restoration and primary forest. It proposes that previous land use and the type of regeneration can influence the recovery time of the forest.