Introduction

Clade-age-dependent diversification under high species turnover shapes species richness disparities among tropical rainforest lineages of Bulbophyllum (Orchidaceae)

“…Accordingly, the Early Miocene radiation of the Asia-Pacific lineage [ c. 19.12 (14.81–23.85) Ma] coincides with the rising of global temperatures after the comparatively cool Oligocene [59] and could have been further promoted by the mid-Miocene Climatic Optimum (MMCO, c . 17–15 Ma [59]) as well as the concomitant strengthening of the East Asian summer monsoon [60, 61]. Subsequently, now sunken islands in the western Indian Ocean, which likely existed permanently above sea level throughout the Oligocene and Miocene (Bradler et al [62]; and references therein), could have acted as stepping-stones facilitating the genus’ dispersal from India and further Asia to the Madagascan/African region [62, 63].…”

“…Why Bulbophyllum expanded during glacials could relate to several taxon-specific traits conferring high tolerance to drought and water stress (e.g., water-storing pseudobulbs; thick, evergreen leaves minimizing transpiration; water-saving crassulacean acid metabolism/CAM [43, 49]). In addition, there is increasing evidence from palaeo-data and/or phylogeographic studies that the climate of several areas where Bulbophyllum expanded at the LGM was still suitable (e.g., relatively humid) to sustain TRF communities over the last glacial cycles, whether in Africa (e.g., Congo River Basin [65]; Niger River Catchment, Eastern Arc Mountains of Tanzania [61]; coastal West Africa [14]), Madagascar (northern and eastern parts [18]), the Neotropics (Brazilian Atlantic Forest [85, 86]) or the Asia-Pacific region (Sundaland [17, 87]). Hence, together with these recent studies, the present ENM data challenge the long-held notion that TRFs mostly fragmented during glacial periods.…”

The comparative phylogeography of fruit bats of the tribe Scotonycterini (Chiroptera, Pteropodidae) reveals cryptic species diversity related to African Pleistocene forest refugia

“…The onset of glaciation in the Northern Hemisphere took place at the Pliocene/Pleistocene boundary, at around 2.6 Mya, and from that period until today, the Earth's climate has been characterized by a succession of about 50 glacial-interglacial cycles [1]. During glacial periods, the decrease of temperature and precipitation had major impacts on the fauna and flora of high and middle latitudes, but also in low latitudes, where widely distributed rainforests of the Pliocene were partly replaced by more open vegetation [4].…”

“…The Quaternary, which includes the Pleistocene and Holocene epochs, started at the onset of the Northern Hemisphere glaciations, approximately 2.58 Mya, and continues to the present-day. It was characterized by a succession of about 50 glacial/interglacial cycles, which are attributed to variation in solar radiation [1]. The decrease of temperature and precipitation during glacial periods had major impacts on the fauna and flora of high and middle latitudes, but also in low latitudes, where widely distributed Pliocene rainforests, which today contain high levels of biotic endemism and richness [2,3], were partly replaced by more open vegetation [4].…”

A 33,000-year paleohydrological record from Sanamere Lagoon, north-eastern tropical savannas of Australia

“…Although the importance of the tropics as a major driver of global climatic systems and hydrological cycles has been previously highlighted (e.g., Chiang, 2009), current knowledge of how long-term environmental change has affected these regions and their hydrological responses to past environmental change is limited (Metcalfe and Nash, 2012). As a prime example, the tropical savanna region of northern Australia (that covers 23% of the continent) (Fig.…”