Estrutura e riqueza de hepáticas (Marchantiophyta) epifíticas em áreas fragmentadas de Cerrado com borda natural e antrópica / Estrutura e riqueza de hepáticas (Marchantiophyta) epifíticas em áreas fragmentadas de Cerrado com borda natural e antrópica / Structure and richness of the epiphytic liverworts (Marchantiophyta) in fragmented areas of Cerrado with natural edge and anthropogenic / Structure and richness of the epiphytic liverworts (Marchantiophyta) in fragmented areas of Cerrado with natural edge and anthropogenic

Lailah Luvizoto Assad

The damage caused by the proliferation of edge in forest cover, referred to as edge effects are extensive, may occur over large spatial scales influencing species composition, structure and ecological processes in boundaries of ecosystems. However, studies have shown highly variable response patterns of the taxonomic group studied in relation to the landscape. In this context, bryophytes are an ideal group for assessing the impacts of habitat fragmentation because of their sensitivity to changes in microclimate resulting from the loss and degradation of habitats. This study aimed to assess how the communities from epiphytes liverworts (Marchantiophyta) respond to forest edges originated of anthropogenic fragmentation and the natural edges in the grassland-forest transitions in the Cerrado. The study areas are located in the Parque Estadual da Serra de Caldas Novas and in surroundings, including Caldas Novas and Rio Quente cities, state of Goiás. We sampled three habitat types: (1) forest valleys on the slopes of the mountain with abrupt transitions to rocky fields, (2) edge (0 to 10 m) and (3) interior (100 to 110 m) of semideciduous forest fragments surrounded by a matrix of grass. These were the three treatments considered in the analysis, designated for: BN (natural edge), BA (anthropogenic edge) and IF (interior of the fragment). Four plots (1010m) were randomly delimited along transects (10200m) for each treatment in each area. For the sampling in the plots, were selected all trees with perimeter at breast height (PAP) ≥ 20 cm and with minimum coverage of bryophytes of 300cm2. For the quantitative survey of liverworts the interception line method was utilized. Between vegetation parameters, the number of individual trees had positive relationship with richness and abundance in liverworts, whereas basal area had positive relationship with coverage demonstrating the importance of these parameters in liverworts community struture. The richness of liverworts was higher in natural and anthropogenic edges in relation to the interior of the fragments demonstrating that the type of edges do not seem to influence the richness of the liverworts and this increased richness at the edges may be related with the intermediate disturbance hypothesis. Coverage of liverworts was higher in BN than BA, while the BN had distinct floristic composition of BA and IF, that may reflect the environmental peculiarities (moisture, temperature and solar radiation). The evaluation of edge effects on life forms and preference of habits shows some important trends to understand the responses of the liverworts, mainly due to increased frequency of pendant life-forms with low tolerance to desiccation and higher frequency of epiphytes shadow in natural edges. This indicates that the use of functional groups in monitoring the effects of fragmentation can provide a large generalization for the evaluation of responses the liverworts.

AUTOR(ES)

FONTE

DATA DE PUBLICAÇÃO

RESUMO

ASSUNTO(S)

ACESSO AO ARTIGO

Documentos Relacionados