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Microfossil and sedimentological data from a 3.1 m core extracted from a reservoir (baray) at the ancient Cambodian settlement of Angkor Borei in the Mekong Delta have provided a continuous record of sedimentation and paleoenvironments dating from about 2000 cal yr B.C. Palynological data indicate that for much of the cal. 1st and 2nd millennia B.C. mangroves dominated the regional vegetation, while extensively and regularly burnt grasslands dominated the local vegetation. Turbid, nutrient-rich standing water characterized the core locality, perhaps suggesting a connection with rivers in the area. An abrupt change during the cal. 5th to 6th centuries A.D. involved a dramatic reduction in grasslands and the expansion of secondary forest or re-growth taxa. These changes are synchronous with an abrupt decline in the concentration of microscopic charcoal particles in the sediments, and the colonization of the core locality by swamp forest plants. These changes are taken to indicate a shift in land-use strategies or, possibly, a period of land abandonment. The age for the construction of the baray is interpreted to be in the 17th–19th centuries, but this dating remains speculative. Construction of the Angkor Borei baray exploited a preexisting body of standing water, so its construction was fundamentally different from the methods used at the Angkorian capital in northern Cambodia. © 2003 Wiley Periodicals, Inc.

Anthropogenic soil erosion reduces soil productivity, compromises freshwater ecosystem services, and drives geomorphic and ecological change in rivers and floodplains. It is now well accepted that the rate of anthropogenic soil erosion exceeds the rate of soil production by several orders of magnitude in many parts of Earth (Montgomery 2007), threatening the sustainability of food production that is so essential to human well-being. Deposition of the eroded soil downstream has profoundly altered the structure and function of fluvial and deltaic ecosystems, often with negative impacts on the societies and economies that depend on them (Hoffmann et al. 2010). The legacy of these impacts exerts strong influence over modern and future ecosystem functions. In many agricultural ecosystems, natural processes no longer primarily control soil erosion and deposition, and greatly altered sediment fluxes are a key marker of the Anthropocene (Syvitski and Kettner 2011).

There are few palaeoenvironmental data from the Indo-Chinese peninsula that document environmental and climatic conditions prior to the Holocene. This study of pollen and spores from a small peat-swamp in north-east Thailand provides a record of vegetation change covering ca. 40,000 years B.P. (Before Present). These data indicate that the region supported a Fagaceous-Coniferous forest, similar to contemporary vegetation described from south-west China. Climatic conditions were cooler and probably drier than present day climates in Thailand. Levels of biomass burning are relatively high throughout this period. Tropical broad-leaf deciduous forest becomes dominant at the Pleistocene/Holocene boundary with the fragmentation of Fagaceous-Coniferous forest in response to increased temperatures.

Pollen and phytolith analyses of a 6.18 m core (3KUM) extracted from Lake Kumphawapi, northeastern Thailand provide the oldest continuous sequence of vegetation change for continental Southeast Asia. The combined microbotanical data suggest human/environment interaction from at least the Early Holocene to the present. An amelioration of arid Late Pleistocene environments in this region is indicated by the development of herbaceous swamp and swamp forest communities at the core site. Early Holocene vegetation changes reflect the rapid expansion and diversification of mixed-deciduous forests, which may also have been disturbed by anthropogenic burning. The Late Holocene reduction in dry-land forest and the subsequent establishment of secondary-growth forests, suggests a further change to burning regimes. Changes in both human subsistence strategies as well as climate occurred during this period, including the critical transition to rice agriculture. These changing subsistence patterns are reflected in the Kumphawapi record by evidence of shifting burning regimes, including indirect evidence of agricultural activities in the Middle Holocene. The timing and nature of agricultural development indicated by the archaeological data for northeastern Thailand needs to be re-evaluated in order to account for the burning regimes and vegetation changes evident in the 3KUM microfossil record.

The Khmer kingdom, whose capital was at Angkor from the 9(th) to the 14(th)-15(th) century, was founded in 802 by king Jayavarman II in a city called Mahandraparvata, on Phnom Kulen. Virtually nothing more is known of Mahandraparvata from the epigraphic sources, but systematic archaeological survey and excavation have identified an array of cultural features that point to a more extensive and enduring settlement than the historical record indicates. Recent remote sensing data have revolutionized our view, revealing the remains of a city with a complex and spatially extensive network of urban infrastructure. Here, we present a record of vegetation change and soil erosion from within that urban network, dating from the 8(th) century CE. Our findings indicate approximately 400 years of intensive land use, punctuated by discrete periods of intense erosion beginning in the mid 9(th) century and ending in the late 11(th) century. A marked change in water management practices is apparent from the 12(th) century CE, with implications for water supply to Angkor itself. This is the first indication that settlement on Mahendraparvata was not only extensive, but also intensive and enduring, with a marked environmental impact.

Diatoms possess a number of attributes which contribute to their suitability as biological indicators. They are highly sensitive to water chemistry changes, abundant in aquatic environments, largely cosmopolitan in distribution, less habitat dependent than macroinverte-brates and have a well-studied taxonomy and ecology. Furthermore, the preservation of diatom valves in lake sediments means that they can provide otherwise unavailable baseline data which can be used to assess and contextualize human impacts on aquatic ecosystems. The value of diatoms as bioindicators in contemporary and palaeolimnological studies has been well established overseas. Despite this, they have been under-utilized in Australia. This paper outlines some of the applications and potential for the use of diatoms as biological indicators in Australia.

Participative Action Research (PAR) is a collaborative process in which members of an organization work with researchers in a process of exploration and change. In contrast to traditional research processes, PAR employs a cyclical and iterative process of exploration, discovery, action to implement change and evaluation. This chapter reports on a participative action research project in the Department of Cardiology at the Royal Children’s Hospital in Melbourne. The Department worked with the Creative Organisational Systems (COS) Group at RMIT University in Melbourne between August 2006 to March 2008 to explore and improve the organizational culture of the Department.

The wetlands of the lower Mekong River Basin are ecologically and socioeconomically significant, but they are threatened by predicted climatic change. The likely response of wetland ecosystems to altered flooding regimes and surface-water chemistry is unknown in detail and difficult to model. One way of exploring the impact of climate change on wetland ecosystems is to utilize proxy environmental data that reveal patterns of change over geological time. In recent years, the coverage and resolution of proxy climatic data have improved markedly in the region. Recent evidence of the South China Sea transgression into southern and central Cambodia and paleobotanical evidence from the Tonle Sap (“Great Lake”) and elsewhere allow us to explore how periods of higher-than-present sea level and increased monsoon rainfall in the past have impacted the wetland ecology of the lower Mekong River Basin.

Investigating the use of land during the medieval period at the celebrated ceremonial area of Angkor, the authors took a soil column over 2.5m deep from the inner moat of the Bakong temple. The dated pollen sequence showed that the temple moat was dug in the eighth century AD and that the agriculture of the immediate area subsequently flourished. In the tenth century AD agriculture declined and the moat became choked with water-plants. It was at this time, according to historical documents, that a new centre at Phnom Bakeng was founded by Yasovarman I.

Dan Penny, Christophe Pottier, Matti Kummu, Roland Fletcher, Ugo Zoppi, Mike Barbetti, Tous Somaneath Hydrological History of the West Baray, Angkor, revealed through Palynological Analysis of Sediments from the West Mebon In addition to its extraordinary monuments, the medieval Cambodian capital of Angkor is characterised by an extensive network of canals, embankments and reservoirs. The operation of this water management infrastructure, and its role in the demise and eventual abandonment of Angkor, is a topic of persistent debate. This paper presents new palaeo-botanical information from the West Mebon, a small water temple located within the West Baray reservoir. The West Mebon is a vital location in understanding the hydraulic history of the West Baray and the enormous web of canals and embankments that form its catchment to the north and northwest. Hydraulic connection between the Mebon and the surrounding baray means that the accumulated sediment within the Mebon preserves an archive of plant response to changing water levels within the Mebon, which acts as a proxy for water levels within the baray. Palynological analysis indicates a dramatic reduction in the volume of water brought into storage in the West Baray from the late 12th century, perhaps reflecting a change in the techniques or the capacity to store and transport water. The fact that the West Baray appears to have had low or minimal water levels for much of the period from the 13th to the late 16th century has important implications for the debate surrounding the purpose of the great barays., Dan Penny, Christophe Pottier, Matti Kummu, Roland Fletcher, Ugo Zoppi, Mike Barbetti, Tous Somaneath Hydrological History of the West Baray, Angkor, revealed through Palynological Analysis of Sediments from the West Mebon En marge de ses spectaculaires monuments, Angkor, capitale du Cambodge ancien, se caractérise par un vaste réseau de canaux, de digues et de réservoirs. La fonction de cette infrastructure hydraulique et son rôle dans le déclin et l'abandon d'Angkor sont toujours sujets à débat. Cet article présente de nouvelles informations paléo-botaniques recueillies au Mebon occidental, un petit temple situé au centre du réservoir du Baray occidental. Le Mebon occidental est un endroit crucial pour saisir l'histoire hydraulique du Baray occidental et de son réseau de canaux et de digues qui recouvrent l'aire en amont, au nord et au nord-ouest. La connexion entre le Mebon et son Baray permet de considérer que le sédiment accumulé au Mebon a gardé la trace des plantes aquatiques qui s'y sont développées et de leur évolution en fonction des niveaux d'eau présents dans le Mebon, et donc dans le Baray. L'analyse palynologique indique une nette réduction du volume d'eau stocké dans le Baray occidental à partir de la fin du XIIe siècle, reflétant peut-être un changement des techniques ou des capacités à stocker, à transporter et à utiliser l'eau. Que le Baray occidental ait eu des niveaux d'eau bas depuis le début du XIIIe jusqu'à la fin du XVIe siècle présente des implications importantes pour le débat sur la fonction des grands Baray en particulier, et sur la Cité Hydraulique en général., Penny Dan, Pottier Christophe, Kummu Matti, Fletcher Roland, Zoppi Ugo, Barbetti Mike, Tous Somaneath. Hydrological History of the West Baray, Angkor, revealed through Palynological Analysis of Sediments from the West Mebon. In: Bulletin de l'Ecole française d'Extrême-Orient. Tome 92, 2005. pp. 497-521.

Sedimentological, limnological and palynological analyses of a sediment core from a lowland site in West-Java, Indonesia, provide a detailed palaeoenvironmental record for the Late Glacial and the Holocene. The record suggests open vegetation under inferred drier climatic conditions for the Late Glacial. However, there is no unequivocal evidence for cooler conditions at this time. The onset of the Holocene coincides with a change to more humid climatic conditions, with the development of a fern-rich closed forest vegetation type. Dramatic changes in diatom community composition provide a striking record of habitat change associated with lake shallowing, but this process appears to be a result of basin in-filling rather than variations in precipitation/evaporation balance associated with climatic fluctuations. Evidence for human impact on the vegetation development is restricted to the last few hundred years.