Abstract
Abstract: In recent years there has been increasing attention in patterns of β-diversity and mechanisms related to variations in species composition. In this study, we evaluated beta diversity patterns of bromeliads growing on cliffs immersed in Atlantic Forest. We hypothesized that the species composition varies according to the spatial scale, inferring that there is a replacement of species influenced mainly by environmental factors. The study was carried out on sandstone cliffs included in contiguous but distinct vegetation formations: Evergreen and Seasonal forests. Twenty-four vertical rocky outcrops were sampled. The spatial variation in species composition was evaluated by two β-diversity components, turnover and nestedness. Multivariate analysis and variation partitioning were performed to distinguish niche and stochastic processes. We recorded 26 bromeliad species and a significantly higher contribution of turnover explaining beta diversity. Environmental factors affect β-diversity patterns of Bromeliaceae. However, individually, the environmental predictors do not explain the data variation. Environmental variations spatially structured, and spatial variables determinate the dissimilarity in the composition of bromeliads on cliffs. Thus, our results revealed that both environmental and spatial effects can act together to define the floristic composition of rock-dwelling bromeliad communities.
Highlights
Investigating patterns of species distribution is one of the essential objectives of ecology and a challenge to understand the complex set of processes driving the structure of communities
In Seasonal forest, both βSIM and βSOR were influenced by the Mean Annual Temperature (AT), Temperatura Seasonality (TS), Temperature Annual Range (TR) and Continentality (CO)
Our results showed how the composition of bromeliads growing on this substrate varies at the boundary between evergreen and seasonal forest types, and how spatial and environmental factors influence the structuring of these communities
Summary
Investigating patterns of species distribution is one of the essential objectives of ecology and a challenge to understand the complex set of processes driving the structure of communities. The variation in species composition among communities (β-diversity) can be related to the influence of several biotic and abiotic conditions (Cottenie 2005). The use of beta diversity measures based on dissimilarity between samples or communities can clarify several questions about the distribution of species, allowing inferences on environmental effects, and the influence of spatial or random factors on the establishment of species (Baselga 2010). Niche-based processes assume that the establishment of a species is limited by environmental filters (Grinnell, 1917; Legendre & Legendre, 1998), while neutral processes assume that dispersion acts as one of the main mechanisms in determining the diversity patterns (Hubbell 2001). The structure of communities is determined by two distinct processes acting on the regional pool of species (Hubbell 2001, Gaston & Chown 2005)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
