Briófitas de um fragmento de floresta ombrófila aberta no município de Porto Velho e novas ocorrências para Rondônia, Brasil

Abstract

The aim of this study was to survey the bryophytes occurring in an opened ombrophilous forest fragment of lowlands in the western Amazon, located in the campus of the Universidade Federal de Rondônia. The bryophytes were collected on substrates available in a 1 ha plot divided into 100 sub-plots of 10 x 10 m, and was contemplated only the understory. 406 samples were analyzed which resulted in 33 species (18 liverworts and 15 mosses). The families Lejeuneaceae, Sematophyllaceae and Calymperaceae were the most frequent in the studied area and the prevalence of these in tropical forests have been widely reported. The generalist species were the most representative (45%), followed by shade (24%) and sun (15%) experts. The families Plagiochilaceae and Calypogeiaceae are first reported to Rondônia, besides 13 new species records: Archilejeunea fuscescens (Hampe ex Lehm.) Fulford; Calypogeia laxa Gottsche & Lindenb.; Cheilolejeunea aneogyna (Spruce) A. Evans; Cheilolejeunea rigidula (Mont.) R.M.Schust.; Cheilolejeunea oncophylla (Aongström) Grolle & E.Reiner; Cololejeunea gracilis (Ast.) Pócs; Cololejeunea subcardiocarpa Tixier; Cololejeunea verwimpii Tixier; Lejeunea caulicalyx (Steph.) E.Reiner & Goda; Lejeunea immersa Spruce; Lejeunea phyllobola Nees & Mont.; Plagiochila raddiana Lindenb; and Prionolejeunea denticulata (Weber) Schiffn. These results add relevant information to the knowledge of the local bryoflora reinforcing the indications of systematic sampling to investigate specific substrates in future inventories.