The Middle Yangtze Region in China Is One Place Where Rice Was Domesticated: Phytolith Evidence from the Diaotonghuan Cave, Northern Jiangxi

Article excerpt

Introduction

Rice, Oryza saliva L., is one of the most important cereal crops in the world, and its emergence as a domesticated subsistence plant drives much of the interest and research in archaeology in South and East Asia. The homeland of domesticated rice has been proposed as:

1 a specific area, such as India (Vavilov 1926; Ramiah & Ghose 1951), South China (Ding 1957), Southeast Asia (Spencer 1963) and the Yangtze valley in China (Yan 1982; 1989)

2 a biogeographic region, such as the so-called 'belt region' with a great diversity of Oryza species (Chang 1976), or

3 an ecological zone, such as coastal swamp habitats (Higham 1995).

There are two criteria for locating a potential place of incipient rice domestication. One is the existence of a wild species which could be the progenitor of domesticated rice; another is the presence of archaeological evidence, especially rice remains with sufficient antiquity, to indicate that domestication occurred in that region. Recently, the earliest rice remains known to date were discovered at the Pengtoushan site, located in the middle Yangtze region, China [ILLUSTRATION FOR FIGURE 1 OMITTED] (Pei 1989; Yan 1991). The site was dated to 8000-8500 BP (Pei 1995) based on more than 20 conventional and AMS radiocarbon dates obtained from charcoal, organic incrustations in pottery, as well as charred rice extracted from pottery (Hedges et al. 1992; Chen & Hedges 1994). The wild rice Oryza rufipogon Griff., a probable progenitor of domesticated rice, grows today in the middle Yangtze region (Cooperative Team of Wild Rice Resources Survey 1984).

This paper reports on part of the interdisciplinary analysis of the Sino-American Jiangxi Origin of Rice project (SAJOR), directed by Richard MacNeish and Yan Wenming. The goal of the project was to search for the origin of rice agriculture in the middle Yangtze region by conducting excavations at several early cave sites located in northern Jiangxi, China. During the excavations, flotation was utilized for recovering plant macroremains, but the results were unsatisfactory due to the poor preservation of seeds and other plant parts (Zhao 1996). Palynologists attempted to use size and number of Poaceae pollen grains recovered from the sites to identify rice (Wang et al. 1995), but Oryza pollen cannot reliably be distinguished from other grass pollen. Therefore, phytolith analysis was employed as the research method to recover and identify rice remains in the project.

The site and its date

Among the cave sites excavated by the SAJOR project, the Diaotonghuan cave (where a full-scale excavation was carried out) is the focus of discussion here. The Diaotonghuan cave, also called the Wangdong cave, is located in Wannian County, northern Jiangxi Province [ILLUSTRATION FOR FIGURE 1 OMITTED]. It is situated within a small, swampy basin named the Dayuan Basin. The basin is approximately 4 km east-west by I km north-south and surrounded on all sides by limestone hills. The cave is a tunnel passage situated at the top of a small limestone hill about 60 m high. An area 5 m wide by 8 m long was excavated in the centre of the cave. A total of 16 clear-cut stratigraphic zones, from Zone A to Zone P, were identified in the 5-m deep trench [ILLUSTRATION FOR FIGURE 2 OMITTED] (Cunnar 1995). A considerable amount of archaeological data has been recovered, including stone implements, potsherds, bone and shell artefacts, and extremely abundant animal bones.

Radiocarbon dates were obtained from the site (MacNeish & Taylor 1995). However, most of the dates appear too early to apply to their associated cultural assemblages (Zhao 1996). A relative chronology can be proposed based upon the presence of a well-defined stratigraphy, combined with careful analysis of cultural remains, as well as comparison with other dated sites in the region. TABLE 1 provides the estimated dates for the six upper zones, which are briefly discussed below. …