Anthropogenic hillslope terraces and swidden agriculture in Jiuzhaigou National Park, northern Sichuan, China

Abstract

Small, irregular terraces on hillslopes, or terracettes, are common landscape features throughout west central China. Despite their prevalence, there is limited understanding of the nature of these topographic features, the processes that form them, and the role humans played in their formation. We used an interdisciplinary approach to investigate the geology, ecology, and cultural history of terracette development within Jiuzhaigou National Park, Sichuan Province, China. Terracettes occur on south facing, 20° slopes at 2500 m elevation, which appears to coincide with places people historically preferred to build villages. Ethnographic interviews suggest that traditional swidden agricultural cycles removed tree roots, causing the loess sediments to lose cohesion, slump, and the terrace risers to retreat uphill over time. This evidence is supported by landslide debris at terracette faces. Archaeological analysis of terracette sites reveal remains of rammed spread soil structures, bones, stone tools, and ceramics dating from at least 2200 years before present within a distinct paleosol layer. Radiocarbon and optically stimulated luminescence dating of terracette sediments ranged in age from between 1500 and 2000 14C yr BP and between 16 and 0.30"ka, respectively. These multiple lines of evidence indicate a long history of human habitation within Jiuzhaigou National Park and taken together, suggest strong links between terracette formation and human-landuse interactions.

Environmental Reviews and Case Studies: Is the Returning Farmland to Forest Program a Success? Three Case Studies from Sichuan

“…Jiuzhaigou is also home to about 1,200 Tibetans who until very recently were subsistence agro-pastoralists, historically inhabiting the nine villages that give the valley its name, growing corn, wheat, barley, potatoes, hemp, turnips, and formerly opium, mostly in clearings in a layer of rich loess soil at about 2,300 and 2,700 meters elevation (Henck et al, 2010), pasturing sheep and goats in fallow agricultural plots and yaks in the alpine meadows, and using forests for firewood (deciduous species including oak, birch, and maple) and construction (conifers including pine and spruce).…”

The influence of terracettes on the surface hydrology of steep-sloping and subalpine environments: some preliminary findings

“…Whilst much has been written about the origin of terracettes and the processes thought to have led to their formation (e.g. Ødum, 1922;Rahm, 1962;Bell, 1981;Buckhouse and Krueger, 1981;Auzet and Ambroise, 1996;Henck et al, 2010), two lines of thought usually prevail. The first is that the upper layer of soil gradually moves downslope by soil creep (Carson adn Kirkby, 1972;Anderson and Cox, 1978;Waugh, 1995;Heimsath et al, 2002;Anderson and Anderson, 2011).…”

Early evidence for the use of wheat and barley as staple crops on the margins of the Tibetan Plateau

“…In addition, a few pieces of low-fired red sandyinclusion pottery that is typical of the stone-cist grave period were found in fill layers of the site, suggesting that the site had several earlier phases of occupation. Zooarchaeological work at the Ashaonao site is currently under way, and preliminary results suggest use of pastoral animals such as sheep (38).…”