• Energy Research

AbstractThe role of Pleistocene climate changes in promoting evolutionary diversification in global biota is well documented, but the great majority of data regarding this subject come from North America and Europe, which were greatly affected by glaciation. The effects of Pleistocene changes on cold‐ and/or dry‐adapted species in tropical areas where glaciers were not present remain sparsely investigated. Many such species are restricted to small areas surrounded by unfavourable habitats, which may represent potential interglacial microrefugia. Here, we analysed the phylogeographic structure and diversification history of seven cactus species in the Pilosocereus aurisetus complex that are restricted to rocky areas with high diversity and endemism within the Neotropical savannas of eastern South America. We combined palaeodistributional estimates with standard phylogeographic approaches based on two chloroplast DNA regions (trnT‐trnL and trnS‐trnG), exon 1 of the nuclear gene PhyC and 10 nuclear microsatellite loci. Our analyses revealed a phylogeographic history marked by multiple levels of distributional fragmentation, isolation leading to allopatric differentiation and secondary contact among divergent lineages within the complex. Diversification and demographic events appear to have been affected by the Quaternary climatic cycles as a result of isolation in multiple patches of xerophytic vegetation. These small patches presently harbouring P. aurisetus populations seem to operate as microrefugia, both at present and during Pleistocene interglacial periods; the role of such microrefugia should be explored and analysed in greater detail.

AbstractThe role of Pleistocene climate changes in promoting evolutionary diversification in global biota is well documented, but the great majority of data regarding this subject come from North America and Europe, which were greatly affected by glaciation. The effects of Pleistocene changes on cold‐ and/or dry‐adapted species in tropical areas where glaciers were not present remain sparsely investigated. Many such species are restricted to small areas surrounded by unfavourable habitats, which may represent potential interglacial microrefugia. Here, we analysed the phylogeographic structure and diversification history of seven cactus species in the Pilosocereus aurisetus complex that are restricted to rocky areas with high diversity and endemism within the Neotropical savannas of eastern South America. We combined palaeodistributional estimates with standard phylogeographic approaches based on two chloroplast DNA regions (trnT‐trnL and trnS‐trnG), exon 1 of the nuclear gene PhyC and 10 nuclear microsatellite loci. Our analyses revealed a phylogeographic history marked by multiple levels of distributional fragmentation, isolation leading to allopatric differentiation and secondary contact among divergent lineages within the complex. Diversification and demographic events appear to have been affected by the Quaternary climatic cycles as a result of isolation in multiple patches of xerophytic vegetation. These small patches presently harbouring P. aurisetus populations seem to operate as microrefugia, both at present and during Pleistocene interglacial periods; the role of such microrefugia should be explored and analysed in greater detail.

The vast Amazonian biome still poses challenges for botanists seeking to know and recognize its plant diversity. Brazilian northern cities are expanding fast, without considering the regional biodiversity, and urban plantings of almost exclusively exotic species are taking place. It is paramount that the correct identity of such trees is ascertained before procurement of the seeds and young plants, as the use of popular names may lead to importation of plant material from elsewhere, with potential introduction of invasive species. The abundant local diversity also leads to the need to score the most suitable species within a given region. Following the preparation of authoritatively named floristic lists in Southeastern Pará state, we proceeded to score and rank the most suitable trees for urban planning using different characteristics such as size, ornamental value, ecologic role, resilience and known methods of propagation. From an initial 375 species list, 263 species were ranked according to their suitability for street and urban area plantings and visualized using a Venn diagram. A final list with the 49 of the highest-ranking species was further analysed regarding their pollination and phenology period and two types of dissimilarity analyses were provided to aid practitioners in matching and choosing groups of species. Different local vegetation types mean that similar floristic lists must be used to extract cohorts of suitable plants to increase the urban richness in the eight Brazilian states that are included in the Amazonian biome.

The vast Amazonian biome still poses challenges for botanists seeking to know and recognize its plant diversity. Brazilian northern cities are expanding fast, without considering the regional biodiversity, and urban plantings of almost exclusively exotic species are taking place. It is paramount that the correct identity of such trees is ascertained before procurement of the seeds and young plants, as the use of popular names may lead to importation of plant material from elsewhere, with potential introduction of invasive species. The abundant local diversity also leads to the need to score the most suitable species within a given region. Following the preparation of authoritatively named floristic lists in Southeastern Pará state, we proceeded to score and rank the most suitable trees for urban planning using different characteristics such as size, ornamental value, ecologic role, resilience and known methods of propagation. From an initial 375 species list, 263 species were ranked according to their suitability for street and urban area plantings and visualized using a Venn diagram. A final list with the 49 of the highest-ranking species was further analysed regarding their pollination and phenology period and two types of dissimilarity analyses were provided to aid practitioners in matching and choosing groups of species. Different local vegetation types mean that similar floristic lists must be used to extract cohorts of suitable plants to increase the urban richness in the eight Brazilian states that are included in the Amazonian biome.