Lejeuneceae (Hepaticae) do município de Tucuruí, Pará

Abstract

The municipality of Tucuruí is home to the largest hydroelectric power plant in Pará State. In 1986, when the Tocantins River was dammed, a lake of approximately 2,875 kmZ was formed, flooding a large area of primary forest. During the floristic survey for the environmental impact assessment, bryophytes were not inventoried. Among the species of liverworts found in tropical lowland forests, about 75% are species of the family Lejeuneaceae, and this group is of great importance for the knowledge of the brioflora of the region. Therefore, the aim of this work was to make an inventory of the species of Lejeuneaceae which occur on the islands and areas around Tucuruí Lake, recording the substrata and ecosystems of occurrence and thus contributing to the knowledge of the brioflora of Pará State. The collection of material totaled 1,500 samples of bryophytes, collected only from the understory of the vegetation covering the islands and in areas adjacent to the lake. To date, 43 species of Lejeuneaceae have been identified, distributed in 24 genera. The species Cololejeunea subcardiocarpa Tixier and Lejeunea quinqueumbonata Spruce are first occurrences for the state of Pará. It can be concluded that the Lejeuneaceae family is highly diverse in the Tucuruí area, represented by 43 species, with new occurrences. This fact alone is important enough to prove the need for more in-depth studies of the liverworts flora in the Northern region. Together with the expansion of specific diversity in this type of inventory, there is also the importance of the knowledge gained about the ecology of the species, such as preferred substrates and ecosystems, geographical distribution patterns and adaptation.