The 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.

Historical patterns of connection and isolation of the impressive biological diversity of the Amazon Basin have been the subject of extensive debate, based on evidence drawn from distributional patterns of endemic species, vegetation histories from palynological studies, and geological studies. We develop species-specific ecological niche models based on current occurrence patterns of 17 species of birds and woody plants, which we project onto modelled Pleistocene (Last Glacial Maximum) climatic patterns to reconstruct past potential distributions of each species. Forest species' distributions showed fragmentation at Last Glacial Maximum and these fragments were coincident spatially, whereas savanna species showed no clear trends. Our results suggest that past climate changes fragmented forest species' ranges within a matrix of uncertain composition.

Adaptation, Climate change, Institutional networks, Perceptions of adaptation,

Severe droughts in southern Africa are associated with livelihood impacts, a strain on local economies, and other hardships. Extensive effort has been spent in the past trying to improve responses to periods of extensive drought. There have also been renewed calls for improvements to climate change adaptation by adopting more proactive governance and disaster risk reduction approaches. Few efforts, however, have been made to assess how to learn more from past drought efforts so as to enhance overall resilience to future drought risks. Few have examined the role and contributions of institutions and drought governance, either across spatial scales [from regional (i.e., Southern African Development Community) to national scales (e.g., South Africa) to the very local scale (e.g., Limpopo Province, South Africa)] or across temporal scales (over at least 100 yr). Despite calls for better risk management approaches at all levels, this paper illustrates two points. First, a failure to fully understand, integrate, and learn from past efforts may undermine current and future drought response. Second, state-led drought risk reduction, which remains focused on a financial “bail-out” mentality, with little follow-through on proactive rather than reactive drought responses, is also seriously contributing to the vulnerability of the region to future drought impacts.

O projeto Flora Fanerogâmica do Estado de São Paulo tem se dedicado a inventariar a flora paulistana há quase 20 anos. Conta com a atuação de mais de 200 colaboradores, a maioria do próprio estado, além de pesquisadores de outros estados e do exterior. Desde 2001, foram publicados sete volumes com as monografias de 151 famílias, contendo 3.237 espécies em 722 gêneros. Este projeto foi o ponto de partida para o conhecimento da diversidade das espécies de espermatófitas do estado de São Paulo. A apresentação do checklist neste momento é oportuna por constituir a produção de uma listagem das espécies com identificações certificadas pelos especialistas, além de conter a referência de uma coleção de herbário para a maior parte dos táxons (material-testemunho) ou referência à bibliografia em que a espécie é citada como ocorrente, de forma nativa ou subespontânea, no estado. Dessa forma, é aqui apresentada a listagem das espermatófitas do estado de São Paulo, com 7.305 espécies, distribuídas em 1.776 gêneros e em 197 famílias (segundo Cronquist 1981) ou então 195 (segundo o APG III). Em relação à flora do Brasil, com 31.728 espécies de espermatófitas, o estado São Paulo compartilha de 23% dessas espécies. As famílias mais representativas são Orchidaceae (797 espécies), Asteraceae (676 espécies), Fabaceae (513 espécies), Poaceae (500 espécies), Myrtaceae (304), Rubiaceae (265 espécies) e Melastomataceae (253 espécies) que, juntas, somam 3.308 espécies e constituem mais de 45% do total de espécies de espermatófitas do estado. Considerando a grande diversidade vegetal brasileira, parcialmente expressa em um estado, depreende-se a grande importância da continuidade dos estudos florísticos no Brasil, país provavelmente detentor da maior diversidade vegetal do planeta.