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De Bruyn M.,Bangor University | Stelbrink B.,Humboldt University of Berlin | Morley R.J.,Royal Holloway, University of London | Morley R.J.,Palynova Ltd | And 15 more authors.
Systematic Biology | Year: 2014

Tropical Southeast (SE) Asia harbors extraordinary species richness and in its entirety comprises four of the Earth's 34 biodiversity hotspots. Here, we examine the assembly of the SE Asian biota through time and space. We conduct meta-analyses of geological, climatic, and biological (including 61 phylogenetic) data sets to test which areas have been the sources of long-term biological diversity in SE Asia, particularly in the pre-Miocene, Miocene, and Plio-Pleistocene, and whether the respective biota have been dominated by in situ diversification, immigration and/or emigration, or equilibrium dynamics. We identify Borneo and Indochina, in particular, as major "evolutionary hotspots" for a diverse range of fauna and flora. Although most of the region's biodiversity is a result of both the accumulation of immigrants and in situ diversification, within-area diversification and subsequent emigration have been the predominant signals characterizing Indochina and Borneo's biota since at least the early Miocene. In contrast, colonization events are comparatively rare from younger volcanically active emergent islands such as Java, which show increased levels of immigration events. Few dispersal events were observed across the major biogeographic barrier of Wallace's Line. Accelerated efforts to conserve Borneo's flora and fauna in particular, currently housing the highest levels of SE Asian plant and mammal species richness, are critically required. © The Author(s) 2014. Published by Oxford University Press, on behalf of the Society of Systematic Biologists. All rights reserved.

Lelono E.B.,LEMIGAS | Morley R.J.,Palynova Ltd | Morley R.J.,University of Surrey
Geological Society Special Publication | Year: 2011

Rich palynomorph assemblages have been obtained through a marine Oligocene succession from the East Java Sea (Indonesia) and provide the first instance of an independently dated Oligocene succession from SE Asia that has yielded a good quality palynological record. The succession has been independently dated by nannofossils and foraminifera. The palynomorph succession suggests climatic control on Oligocene vegetation, on which basis a regionally applicable zonation is proposed. The Early Oligocene is characterized by common rain forest elements, suggesting an everwet, rain forest climate. The early part of the Late Oligocene contains much reduced rain forest elements with grass pollen, indicating a more seasonal climate, whereas for the latest Late Oligocene, rain forest elements return in abundance, suggesting a superwet rain forest climate. This palynological succession is similar to that from the Sunda Basin in the West Java Sea, allowing the Sunda Basin succession to be dated by correlation. The study also extends the stratigraphic range of Dacrydium and Casuarina, two plant taxa previously thought to have dispersed from the Australian Plate into SE Asia at the time of the collision with Sunda, to well before the time of collision. A different means of dispersal for these taxa is proposed. © 2011 The Geological Society of London.

Morley R.J.,Royal Holloway, University of London | Morley R.J.,Palynova Ltd | Morley R.J.,Niko Niko
Journal of Limnology | Year: 2013

Tropical peat swamps are more widespread in Sundaland than in any other equatorial region. Also, Cenozoic deposits from the area are rich in coals. The developmental pattern of present day peat swamps from the region has often been used to help clarify that of coals in the geological record. This paper initially reviews the ecology of present day ombrotrophic, rheotrophic and brackish mangrove peat swamps, and their pattern and timing of development during the Holocene and latest Pleistocene based on palynological studies. Then, it attempts to examine the developmental pattern of the peats which led to the formation of Cenozoic coals across the region, based on both published and unpublished datasets generated during the course of hydrocarbon exploration programmes. It is concluded that Cenozoic coals reflect a greater variety of peat forming settings than occurs in the region today. Extensive brackish water peats formed during the Middle and Late Eocene and Middle and Late Miocene, these often being laterally very extensive. Rheotrophic peats also formed widely through most of the Cenozoic. Ombrotrophic kerapah type peats are first recognised in the Late Oligocene, based on their content of common Casuarina type and Dacrydium pollen, and were particularly common during the Early and Late Miocene in the Sunda shelf region. Kerapah peats sometimes developed great thickness. Basinal peats, on the other hand, increased in representation during the course of the Miocene. No convincing evidence for doming in Cenozoic peats has yet been noted, but on the other hand, no really thick coals, which may have been formed from basinal peats, have so far been studied. As a consequence, examples of doming in the rock record from this area are probably yet to be found.

Morley R.J.,Royal Holloway, University of London | Morley R.J.,Palynova Ltd | Morley R.J.,Niko Niko | Morley H.P.,Palynova Ltd
Journal of Limnology | Year: 2013

Sunda region was the scene of widespread rifting during the mid-Cenozoic, resulting in the development of numerous large lakefilled rifts, analogous in scale to the rift valley system of East Africa. The Tonle Sap in Cambodia forms the closest modern analogue for these lakes in the Southeast Asian region. Many of the palaeolakes were long lived, continuing uninterrupted as open lakes for several millions of years during the Oligocene. Smaller rift systems infilled with fluvial sediments, but the majority remained as lakes, and with Late Oligocene subsidence, were transformed by brackish, and in the earliest Miocene, by marine incursion, into large inland seas. These seas reached their greatest extent at the time of the mid Miocene thermal maximum. This paper describes the development and eventual demise of these lakes following marine transgression, and, based on their rich content of pollen and spores, illustrates the variety of fresh and brackish water swamp communities which developed around their margins. The marginal swamps can be divided into: i) seasonally inundated swamps, mainly during the Oligocene, characterised by Barringtonia, Lagerstroemia and grasses/sedges; ii) fern swamps from the Late Oligocene onward; iii) alluvial swamps, often characterised by Pandanus; and iv) peat swamps. The latter can be differentiated into kerapah peat swamps, first occurring during the Oligocene, and basinal peat swamps, becoming widespread from the Early Miocene onward.

Morley R.J.,Palynova Ltd | Morley R.J.,University of Surrey | Morley H.P.,Palynova Ltd
Geological Society Special Publication | Year: 2011

The Neogene climate history of the Makassar Straits has been assessed by combining palynological studies of two Late Quaternary cores from the ocean floor with analyses of petroleum exploration wells from the Makassar Straits, Indonesia, penetrating the Early Pleistocene to Middle Miocene. The two Late Quaternary cores span 30 ka, located offshore the Mahakam Delta, east Kalimantan, and 95 ka, from offshore south Sulawesi. The first provides a record of the vegetation and climate history of the Mahakam catchment, and indicates rain forests through the last 30 ka, but with a cooler last glacial maximum, whereas the second provides a record of vegetation of the Java Sea region and south Sulawesi, and indicates extensive grasslands, suggesting a distinctly seasonal climate, during the last glacial maximum. Based on a climate model constructed from the cores which link sea level change with changes of temperature and seasonality, the history of vegetation and climate for the Makassar Straits is then extrapolated back to the Middle Miocene using the record obtained from the two exploration wells. Results show that the equatorial climate has been everwet since the Middle Miocene, but at subequatorial latitudes seasonal climates became established from the Late Pliocene onward. © 2011 The Geological Society of London.

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