Historical relationships of areas of endemism of the Brazilian Atlantic rain forest: a cladistic biogeographic analysis of harvestman taxa (Arachnida: Opiliones)

Abstract

Based on a cladistic biogeographic analysis of 6 species-level phylogenies of harvestman taxa, we searched for congruence in the historical relationships of 12 areas of endemism of the Brazilian Atlantic Rain Forest. We constructed general area cladograms using Primary Brooks Parsimony Analysis (BPA), BPA of nodes, and paralogy-free subtree analysis. These analyses resulted in 6 general area cladograms, that allow to infer a general pattern of the relationships among areas of endemism from the Brazilian Atlantic Rain Forest. Northern areas resulted related basally showing main disjunctions at the Doce River Valley and Todos os Santos Bay/São Francisco River Valley. The remaining areas of endemism were included in a southern and a southeastern block, separated by the Ribeira do Iguape Valley. Incongruence Length Differences tests showed no significant incongruence among the resulting cladograms and other matrix partitions. We concluded that tectonism and ancient marine transgressions were the probable processes responsible for the main disjunctions, whereas Neogene refugia seem to have caused the more recent disjunctions. The general pattern and redundancy in area relationships suggest a model of main reiterative barriers in diversification at multiple times for the evolution of the Atlantic Rain Forest. The renewal of cladistic biogeography and the search for common biogeographic patterns are discussed.

Historical signatures in the alpha and beta diversity patterns of Atlantic Forest harvestman communities (Arachnida: Opiliones)

“…The separation of the biotas from the Bahia and Pernambuco areas of endemism occurs in the region of the São Francisco River, in which the historic climatic model supported the two large refugia (Carnaval and Moritz 2008). However, other authors claim that the slightly southern D r a f t Todos os Santos Bay region could represent a more effective barrier (Amorin and Pires 1996;Silva et al 2012;DaSilva et al 2017).…”

“…For example, paleoclimate model reconstruction revealed that regions where forest formations persisted over time were coincident with current patterns of endemism and diversity (Carnaval and Moritz 2008), which suggests that those areas represent forest refugia. The role of geographic barriers in those patterns is also investigated (DaSilva et al 2017), and the biome has some well-known spots that are believed to have had a major influence on limiting species distribution and thus shaping diversity patterns, such as the Doce River, in the state of Espírito Santo, and the region in the north of Bahia state, with two geographic ruptures, Todos os Santos Bay and the São Francisco River.…”

Angiosperm endemism in a Brazilian Atlantic Forest biodiversity hot-point

“…Due to both high number of endemic species and threatened conservation status, the Atlantic Forest is considered a top-priority biodiversity hotspot for plant conservation (Mittermeier et al 2005;Eisenlohr et al 2015), with its endemic vascular plant species representing 2.7% of all vascular plants in the world (Myers et al 2000). Endemic taxa from the Atlantic Forest are not uniformly distributed, and several areas of endemism have been recognized based on distributional data from different groups of organisms, such as trees in general (Thomas et al 1998), Myrtaceae (Murray-Smith et al 2009Giaretta et al 2015), Galipeinae, a subtribe of Rutaceae (Colli-Silva and Pirani 2019), epiphytic angiosperms (Menini-Neto et al 2016), arthropods (Hoffmeister andFerrari 2016), harvestmen (Pinto-da-Rocha et al 2005;DaSilva et al 2015DaSilva et al , 2016, mammals (Costa et al 2000), and birds (Cracraft 1985;Silva et al 2004).…”

Spatial variation in phylogenetic diversity of communities of Atlantic Forest harvestmen (Opiliones, Arachnida)

“…There, one can find great biological diversity and high levels of endemism, combined with ancient and intense anthropogenic pressure. We believe that the study of the phylogenetic diversity patterns of the AF's harvestmen, a group particularly sensitive to environmental disturbances (Bragagnolo et al ., ) and historical factors (DaSilva et al ., ), will: (i) improve the current state of knowledge about the local biodiversity; (ii) provide insights into the processes responsible for the current diversity patterns; and (iii) provide information that might be helpful for conservation. Besides, to our knowledge, this is the first time that the phylogenetic diversity of any invertebrate group from the Atlantic Forest is quantified and analysed.…”