Spatial distribution of functional traits of bryophytes along environmental gradients in an Atlantic Forest remnant in north-eastern Brazil

ABSTRACT Background: Functional trait-based approaches have been used to identify patterns of plant species diversity and composition related to environmental variability/changes. Bryophytes are rapidly affected by perturbations and thus their traits and distribution are expected to show well-defined relationships with environmental variability. Aim: To quantify the impacts of fragmentation on the diversity and structure of epiphytic bryophytes to vertical and horizontal environmental gradients in an Atlantic Forest remnant. Methods: Six functional traits related to water relations and light tolerance were recorded and one of them, the leaf lobule area in liverworts, was selected for morphometric measurements along the gradients analysed. Functional diversity and composition metrics of bryophytes along gradients were compared. Results: Functional diversity changed little along the vertical and horizontal gradients. Conversely, the functional composition of traits changed markedly. Traits related to water storage, such as the presence and area of lobules, and to protection against excess light incidence, such as dark pigments, were more numerous in the canopy and at the fragment edge. Conclusions: Functional composition is more correlated with the vertical and horizontal gradients than functional diversity. The lobule of liverworts stood out as the most relevant trait to explain the adaptive strategies of bryophytes.