Late Quaternary Change in the Mountains of New Guinea
Hope, Geoff, Golson, Jack, Antiquity
At the south and north limits of our region are mountainous areas very different from the open arid spaces of the Australion continent between. In the north, the high country of New Guinea offers a complex and well-studied environmental sequence as the arena for early and puzzling human adaptations, precursor of the extraordinory societies of the
New Guinea Highlands environments
The New Guinea Highlands comprise the central mountains of the huge island of New Guinea, taken here as those places above 800 m with montane or even alpine climates running from central Irian Jaya to the southeast part of Papua.
Surprisingly, we know more about the environmental changes and human occupation of this region than almost any other tropical area, although information is still incomplete and many key questions remain. At present, an intermontane zone from 1200 to 2400 m within the area differs completely from the other zones of Sahul (referred to by Allen 1993 as `Greater Australia') in having dense populations of horticulturalists practising intensive cropping. These remarkable human landscapes are matched by contrasts in the environmental controls, since the intermontane zone has abundant reliable moisture and radiation as well as mild temperatures and reasonably fertile and free-draining soils. That environment creates the opportunity for intensive agriculture, which, it is suggested (e.g. Yen 1991, & this volume), may have developed indigenously in the area, in the course of a human history going back beyond 30,000 years.
The montane region is not all suitable for such agriculture; Brookfield (1964) pointed out that the outer flanks of the ranges are too clouded and wet to support crops except where local topography permits it. These areas have very low populations, in contrast to enclosed highland valleys with locally generated weather patterns. Cloudiness and cold create an upper limit to agriculture at about 2500 m (reaching 3000 m in a few places where the surrounding mountains are very high). The sub-alpine regions near population centres, heavily used for hunting and as communication routes, are drastically altered from a natural state.
Late Pleistocene-early Holocene climatic change is implicated by some (e.g. Golson & Hughes 1980) in agricultural origins in the Highlands, which they see as being marked by the appearance of plants and techniques of cultivation from lower altitudes around 9000 b.p., closely following the attainment of the climatic conditions that allowed it. Questions posed by recent reviews (Allen 1993; Golson 1991a; 1991b; Haberle 1993a; Mountain 1991a; 1991b; Swadling & Hope 1992) concern the transition from late Pleistocene to Holocene climates, the apparent association with it of strategies of landscape manipulation and control, and the relationship of these to the `agricultural' practices of the early Holocene. Spriggs (in press) makes a distinction between agriculture and plant cultivation/domestication in respect of both environmental impact and overall importance in subsistence. Arguing that agriculture makes an abrupt appearance in the New Guinea area with plant and animal introductions associated with the Lapita culture around 3500 years ago, he is inclined to doubt any earlier manifestation in the Highlands.
For the present discussion, the character of early-Holocene occupation in the Highlands is seen in the light both of late-Pleistocene land-use and of later activities up to the introduction of the sweet potato, arguably about 300 b.p.
This review examines these questions for the New Guinea Highlands:
* What is the nature and timing of environmental change across the Pleistocene-Holocene transition that led to the establishment of modern climates and vegetation patterns? * Does the archaeological record support a model of human responses to these environmental changes? * Are there regional or zonal patterns to the changes? …