Volcanic Islands

Fernando de Noronha é um arquipélago localizado na Região Nordeste do Brasil que possui geodiversidade e biodiversidade especiais. Visando valorizar principalmente sua singularidade geológica, estudos e ações estão sendo realizados tendo em vista a possibilidade de seu reconhecimento como um UNESCO Global Geopark. Assim, o objetivo deste artigo é relacionar os geossítios com as atividades de turismo em áreas naturais oferecidas atualmente no arquipélago, buscando contribuir com uma futura estratégia de planejamento do Projeto Geopark Fernando de Noronha. A abordagem desta pesquisa caracteriza-se como descritiva, explicativa e quali-quantitativa e como método de pesquisa foram utilizadas as pesquisa bibliográfica e in loco, que teve como base a observação participante. Conclui-se que é possível realizar atividades em áreas naturais em quase todos os geossítios do arquipélago e apesar de atividades turísticas enfocando o patrimônio geológico ainda não serem efetivamente desenvolvidas, há potencial para a implantação deste novo produto.

The Macaronesian laurel forests (MLF) are dominated by trees with a laurophyll habit comparable
to evergreen humid forests which were scattered across Europe and the Mediterranean
in the Paleogene and Neogene. Therefore, MLF are traditionally regarded as an old,
'Tertiary relict' vegetation type. Here we address the question if key taxa of the MLF are
relictual. We evaluated the relict hypothesis consulting fossil data and analyses based on
molecular phylogenies of 18 representative species. For molecular dating we used the program
BEAST, for ancestral trait reconstructions BayesTraits and Lagrange to infer ancestral
areas. Our molecular dating showed that the origins of four species date back to the Upper
Miocene while 14 originated in the Plio-Pleistocene. This coincides with the decline of fossil
laurophyllous elements in Europe since the middle Miocene. Ancestral trait and area reconstructions
indicate that MLF evolved partly from pre-adapted taxa from the Mediterranean,
Macaronesia and the tropics. According to the fossil record laurophyllous taxa existed in
Macaronesia since the Plio- and Pleistocene. MLF are composed of species with a heterogeneous
origin. The taxa dated to the Pleistocene are likely not 'Tertiary relicts'. Some species
may be interpreted as relictual. In this case, the establishment of most species in the
Plio-Pleistocene suggests that there was a massive species turnover before this time. Alternatively,
MLF were largely newly assembled through global recruitment rather than surviving
as relicts of a once more widespread vegetation. This process may have possibly been
triggered by the intensification of the trade winds at the end of the Pliocene as indicated by
proxy data.

Citation: Opatova V, Arnedo MA (2014) Spiders on a Hot Volcanic Roof: Colonisation Pathways and Phylogeography of the Canary Islands Endemic Trap-Door Spider Titanidiops canariensis (Araneae, Idiopidae). PLoS ONE 9(12): e115078. doi:10.1371/journal.pone.0115078
Studies conducted on volcanic islands have greatly contributed to our current
understanding of how organisms diversify. The Canary Islands archipelago, located northwest of the coast of northern Africa, harbours a large number of endemic taxa. Because of their low vagility, mygalomorph spiders are usually absent from oceanic islands. The spider Titanidiops canariensis, which inhabits the easternmost islands
of the archipelago, constitutes an exception to this rule. Here, we use a multi-locus approach that combines three mitochondrial and four nuclear genes to investigate the origins and phylogeography of this remarkable trap-door spider. We provide a timeframe for the colonisation of the Canary Islands using two alternative approaches: concatenation and species tree inference in a Bayesian relaxed clock framework. Additionally, we investigate the existence of cryptic species on the
islands by means of a Bayesian multi-locus species delimitation method. Our results indicate that T. canariensis colonised the Canary Islands once, most likely during the Miocene, although discrepancies between the timeframes from different approaches make the exact timing uncertain. A complex evolutionary history for the species in the archipelago is revealed, which involves two independent colonisations of Fuerteventura from the ancestral range of T. canariensis in northern Lanzarote and a possible back colonisation of southern Lanzarote. The data further corroborate a previously proposed volcanic refugium, highlighting the impact of the dynamic volcanic history of the island on the phylogeographic patterns of the endemic taxa. T. canariensis includes at least two different species, one inhabiting the Jandia peninsula and central Fuerteventura and one spanning from central Fuerteventura to Lanzarote. Our data suggest that the extant northern
African Titanidiops lineages may have expanded to the region after the islands were colonised and, hence, are not the source of colonisation. In addition, T. maroccanus may harbour several cryptic species.