From the Discussion and Summary ... 'It is suggested that 2000 years ago the destruction of Cambodia's sub-humid climax forests began to change the face of the northern plains. Between 600 and 1200 years ago, dating largely from the 9th century, this area developed a savanna forest complex of vegetation, a biota drastically altered by man's efforts at both dry, shifting agriculture on high, unflooded ground (cheomka system) and his later shifting, dry paddy agriculture on lower ground and flooded terrain within this ecologically diverse habitat. Only on the Kontum Plateau has true cheomka agriculture persisted to the present day by virtue of the rich volcanic soils which the remainder of the northern plains does not possess. Even these rich soils can be made grassland and abandoned, as the Chhlong Plateau demonstrates.That much of this savanna forest is of very recent origin is supported by the absence of a specific burrowing fauna in general, as well as the absence of certain small mammals in particular.From the earliest records the Khmers possessed both domestic cattle and water buffalo and it is known that these animals are the only means of transport for foraging and commerce throughout the northern plains. The burning of the environment to provide better pasture for domestic stock has thus been of selective advantage for those few villagers who remained in this difficult terrain. The present day movement and abandonment of villages seems to attest the precariousness of shifting agriculture, paddy or otherwise, which, lacking technical or administrative direction, provides us with more understanding of the deterioration of the great Khmer civilization of Angkor times. In this case, the present ecology of the northern Cambodian may be a key to his past.If shifting dry paddy agriculture has been precarious on some northern Cambodian soils it has apparently been disastrous or impossible on certain others such as the plinthite podzols. Those villages such as Chhep, favorably located near larger areas of grey hydromorphic soils, may persist for many years. Most villages, apparently, must move periodically or disappear.It would appear that fire in the northern plains of Cambodia has aided in the degradation of some soils and most of the vegetation cover over the area originally clothes by sub-humid climax forests. Fire seems, however, to be an essential factor in maintaining suitable large areas of savanna forest exploitable by both wild herbivores and by a very small population of hardy Cambodians.It remains to determine what parts of northern Cambodia, by reason of edaphic control or otherwise, might have been savanna terrain (with lightning-caused fire) prior to the advent of man. Such information will be necessary to determine the extent of those areas which might be termed natural wild cattle range offering a combination of environmental advantages such as good grazing, permanent waterholes and salt licks.The location of present day Cambodian population centers and their way of life in the hydrophytic community is a return to the days of the Mekong Delta riziculture of their ancestors, along with the rediscovery that a stable and prosperous civilization can be maintained only on true wet land rice and fish. Especially is this so if the strong central control of a god-king cannot make mandatory renewing of the soil by vast and costly irrigation systems.We are led to understand that the protein need of the northern Cambodian is such that it compels him to revert to an earlier pattern of hunting and gathering for his dry season life.Noting the intimacy of his association with the environment and its wild herbivores, and noting his maintenance of this environment by his fire habits, it appears that, over much of northern Cambodia, man and wild cattle have gone a step beyond commensalism to perhaps achieve a state of protocooperation (facultative mutualism of some authors) in which each benefits the other and neither is unduly harmed. Our next task is to determine just how long and profund this relationship has been, and how much and how long fire has really played a role in its development.In the pursuit of this, the zoologist is sobered and stimulated by the fact that the great carrying capacity of the fire-maintained grasslands is largely man-oriented, leading us to examine more closely the ecology and paleoecology of wild cattle since their pliocene ancestors were entombed in the Siwalik foothills of the great Himalayan range.' © 1966, Tall Timbers Research, Inc. Abstract reproduced by permission.