Estudo comparativo da diversidade de musgos (Bryophyta) em diferentes ecossistemas da microrregião do Salgado Paraense, Brasil.

Abstract

The present study deals with the inventory of the mosses from the Salgado Micro-region of Pará, which belongs to the Northeast Meso-region of that State. The latter region is situated at the Coastal Zone, has a total area of 5,812.70 km2 and includes 11 municipalities limited by the Atlantic Ocean. Until 100 years ago, the vegetation of the Salgado region was represented by Terra Firme, Várzea and Igapó forests, savannas and mangroves. Nowadays, however, approximately 90% of the area is covered by secondary forest, especially because the growing settlement and other human activities. The devastation resulted in the lost of knowledge about a high diversified flora, including the group of bryophytes. Therefore, we verified the need of studying the moss flora of this area. The aim of this study was to make a taxonomic survey of the moss species at different ecosystems of municipalities of the Salgado Micro-region; to increase the geographic distribution of the species that were still unknown to the region; to evaluate quali- and quantitatively the diversity of the collected species, comparing it in different ecosystems and substrates; to elaborate keys to identify families, genera and species of the local moss flora; and to contribute to the knowledge of the bryoflora of the Pará State. The intense and randomized collection totalized 508 specimens in eight municipalities, namely, Curuça, Magalhães Barata, Maracanã, Marapanim, Salinópolis, São Caetano de Odivelas, São João de Pirabas e Vigia. The moss flora of the studied municipalities reached 795 occurrences, which correspond to 38 moss species, distributed in 21 genera and 11 families. The species diversity was considered relatively low, taking in account the number of specimens. Sematophyllaceae, Calymperaceae and Leucobryaceae were the best represented families. Semalophyllum suhsimplex (Hedw.) Mitt. was the most frequent species. Campylopus surinamensis Müll. Hak, Groutiella tomentosa (Hornsch.) Wijk & Margad., Leucohryum martianum (Hornsch.), Hampe ex Müll. Hal. Ochrohryum suhulaíum Hampe, Syrrhopodon ligulatus Mont. and Splachnohryum obtusum (Brid.) Müll. Hal. are new reports to the Northeast Meso-region of Pará. The corticicolous substrate was the most colonized, followed by epíxilous and terrestrial one. Epíphyllous and saxícolous species were not found. The ecosystem with the highest number of species was the secondary forest ("capoeira"), followed by open Terra Firme forest. Comparing the results obtained in this study with other studied arcas where there is more primary forest, the impoverishment of the moss diversity is verified. The conservation of the remained ecosystems is of extreme importance to the preservation of their bryoflora.