Vegetation and Land-Use at Angkor, Cambodia: A Dated Pollen Sequence from the Bakong Temple Moat

Article excerpt


Angkor was the location of the capital of the Khmer state for most of the period from the eighth to sometime in the fifteenth and sixteenth centuries AD. By the twelfth century Angkor had become a vast low-density urban complex covering about 1000 sq. km (Fletcher et al. 2003), stretching from the Tonle Sap lake in the south to the Kulen hills in the north. The urban complex incorporated numerous residential loci that were integrated by an immense network of canals and embankments (Figure 1). Within Angkor, successive rulers built major temples and palaces in several locations, shifting the focus of the urban complex until the late twelfth century AD when the central enclosure of Angkor Thorn was constructed. In the seventh to ninth centuries AD, there were concurrent residential loci around Ak Yum, and at Hariharalaya where Jayavarman II established his administration as the newly anointed cakravartin (universal king) after AD 802 (Jacques 1972). Hariharalaya (Roluos) was the site of several major constructions including the massive temple-mountain of the Bakong, the first model of the Angkorian capital (Stern 1954) and the archetype of the pyramidal temple.


One method of investigating this cultural sequence is through palynology, which was successfully applied in the present research project. Vegetation is sensitive to the activities of people and the composition of the flora will often indicate the nature of land use at any given point in time. For example, the abandonment of land or the attenuation of land use will be clearly manifest in the flora, with a predictable successional shift from a cultivated flora to invasive colonising plants, woody secondary forest and climax deciduous forest. Such changes are identifiable in pollen sequences, and can be dated absolutely. Palynological analysis at the site of Hariharalaya had significance for several key periods in Angkorian history, including the date for initial construction on the Bakong site in the eighth century AD, the impact of relocating the administrative centre to the vicinity of Phnom Bakeng in the late ninth century AD, and the conundrum of the demise of Angkor some time in the fifteenth and sixteenth centuries AD. This paper presents the first continuous palynological reconstruction of vegetation change at Angkor, encompassing the entire span of the Classic Angkorian period.

Site description (Figure 2)


Epigraphic evidence indicates that the Bakong temple was inaugurated in AD 881 by King Indravarman I (AD 877-889) (Coedes 1951: 31). It is a five-tiered pyramid, the first tier measuring 65 by 67m, built on an artificial mound, and topped by a central tower built in the twelfth century AD to replace the original, which is thought to have been destroyed some time earlier (Boisselier 1952). The pyramid and its numerous associated buildings are surrounded by two walled enclosures and two moats. The largest moat is 830 by 800m is size and 30-40m wide. The inner moat is 380 by 350m in size, 70-80m in width, and crossed to the east and west by a causeway (Glaize 1993; Pottier unpublished survey). The inner moat of the Bakong is deeply excavated into the regional alluvium, approximately 8m below the level of the temple platform, and 5m below the land surface between the two moats. Consequently, despite the marked seasonal fluctuation in the groundwater table the moat is likely to have carried water since its excavation, providing the conditions necessary for the preservation of organic materials. Groslier (1998: 40) hypothesised the existence of a hydraulic connection between the moats of the Bakong and Preah Ko temples and the Indratataka reservoir to the north (Figure 2), but no evidence of such a link has yet been discovered. Prior to September 2004 when it was cleared, the moat was entirely overgrown with a thick mat of floating vegetation that to our knowledge has not been disturbed throughout the twentieth century--and in all probability much longer--protecting the sediment accumulating on the bed of the moat from disturbance by people or livestock. …