Evolutionary fingerprint, phylogenetic and forest structure of tropical montane Atlantic cloud forests along an elevation gradient

Environmental conditions can change markedly over geographical distances along elevation gradients, making them natural laboratories to study the processes that structure communities. This work aimed to assess the influences of elevation on Tropical Montane Cloud Forest plant communities in the Brazilian Atlantic Forest, a historically neglected ecoregion. We evaluated the phylogenetic structure, forest structure (tree basal area and tree density) and species richness along an elevation gradient, as well as the evolutionary fingerprints of elevation-success on phylogenetic lineages from the tree communities. To do so, we assessed nine communities along an elevation gradient from 1210 to 2310 m a.s.l. without large elevation gaps. The relationships between elevation and phylogenetic structure, forest structure and species richness were investigated through Linear Models. The occurrence of evolutionary fingerprint on phylogenetic lineages was investigated by quantifying the extent of phylogenetic signal of elevation-success using a genus-level molecular phylogeny. Our results showed decreased species richness at higher elevations and independence between forest structure, phylogenetic structure and elevation. We also verified that there is a phylogenetic signal associated with elevation-success by lineages. We concluded that the elevation is associated with species richness and the occurrence of phylogenetic lineages in the tree communities evaluated in Mantiqueira Range. On the other hand, elevation is not associated with forest structure or phylogenetic structure. Furthermore, closely related taxa tend to have their higher ecological success in similar elevations. Finally, we highlight the fragility of the tropical montane cloud forests in the Mantiqueira Range in face of environmental changes (i.e. global warming) due to the occurrence of exclusive phylogenetic lineages evolutionarily adapted to environmental conditions (i.e. minimum temperature) associated with each elevation range.