Bryophytes constitute an important component of tropical rain forests, which provide microhabitats favorable for their establishment. Bryophytes are also quite responsive to changes in microclimate, which makes them good bioindicators. This study aimed to determine the diversity and distribution of bryophytes in upper and lower montane forests of the Chapada Diamantina region of the state of Bahia, Brazil. To that end, we studied community aspects such as richness, diversity, substrates colonized, life forms and floristic similarity between areas and regions. In 2007 and 2008, we collected specimens from six forest sites, located from the north to the south of the Chapada Diamantina region. We identified a total of 205 infrageneric taxa. In comparison with the lower montane forests, the upper montane forests presented higher diversity and species richness, as well as greater numbers of substrates colonized, life form types, species of restricted geographic distribution and species typical of shaded areas. We also found low similarity in the species composition, the populations of the upper and lower montane forests forming two large and distinct groups. Although presenting relatively high floristic homogeneity among themselves, the Chapada Diamantina areas presented little similarity with those of the Atlantic Forest. This can be explained by the differences between the two regions in terms of environmental conditions, precipitation, seasonality, elevation and continentality.

Os musgos acrocárpicos são representados no Parque Estadual das Sete Passagens por 29 espécies distribuídas em 14 gêneros e oito famílias. Dessas espécies, seis espécies representam novas citações para o Estado da Bahia, sendo três novas para a região Nordeste e uma redescoberta para o Brasil. Caracterização morfológica, comentários, grupos briocenológicos, ambiente, distribuição geográfica e distribuição no Brasil são apresentados para todas as espécies estudadas. Ilustrações são apresentadas para as primeiras referências.

The acrocarpic mosses are represented at Parque Estadual das Sete Passagens by 29 species classified in 14 genera and eight families. Among these, six are newly reported for Bahia, of what three are new for Northeast region, and one is a rediscovery for Brasil. Morphological characterization, comments, bryocenological groups, geographic distribution and distribution in Brasil are given for all the studies species. Illustrations are given only for those species which are being reported for the first time.

RESUMO Orthotrichaceae e Rhizogoniaceae são representadas no Parque Estadual das Sete Passagens por 14 espécies distribuídas em cinco gêneros (quatro de Orthotrichaceae e um de Rhizogoniaceae). Destas espécies, quatro representam novas citações para o estado da Bahia, sendo três novas para a região Nordeste. Ilustrações são apresentadas somente para as primeiras referências. Caracterização morfológica, comentários, grupos briocenológicos, ambiente, distribuição geográfica no mundo e no Brasil são apresentados para todas as espécies.

ABSTRACT Orthotrichaceae and Rhizogoniaceae are represented at Parque Estadual das Sete Passagens by 14 species classified in five genera (four from Orthotrichaceae and one Rhizogoniaceae). Among the species, four are firstly reported for Bahia, which three are new for northeast region. Illustrations are given for only species which are being reported for the first time. Morphologic characterization, comments, geographic distribution in world and in Brazil were given for all the species.

Os musgos pleurocárpicos são representados no Parque Estadual das Sete Passagens por 31 espécies distribuídas em 22 gêneros e 12 famílias. Destas, sete representam novas citações para o estado da Bahia, sendo duas novas para a região Nordeste (Daltonia gracilis Mitt. e Sematophyllum swartzii (Schwägr.) W.H. Welch & H.A. Crum). São apresentadas ilustrações das novas referências para o estado da Bahia. Para todas as espécies são apresentadas caracterização morfológica, comentários, grupos briocenológicos, ambiente e distribuição geográfica no Brasil e no mundo.

The pleurocarpic mosses are represented in the State Park of Sete Passagens by 31 species belonging to 22 genera and 12 families. Among those, seven are newly reported for Bahia, of what two are new for the Northeast region (Daltonia gracilis Mitt. and Sematophyllum swartzii (Schwägr.) W.H. Welch & H.A. Crum). Illustrations are given for those species which are being reported for the first time. For all species are given morphological characterization, comments, growth substrate, habitat and geographic distribution in Brazil and in the world.