تجزیه و تحلیل دانه گرده و فیتولیث ازمزارع شالیکاری سنتی در محل چادون، دلتای رود یانگ تسه

A number of paddy fields pertaining to the Majiabang Cultures (5500-3800 years BC) were discovered during the archaeological excavations that were carried out since 1998 at the Chuodun site in the Yangtze River Delta. The pollen and phytolith analyses of two soil profiles from the northeastern part of this site were carried out to trace the agricultural practices of the Neolithic period. The phytolith results showed that rice domestication in the Yangtze River Delta could be traced back to as early as the Majiabang Culture. The pollen assemblage also revealed low levels of aquatic species, similar to that in modern paddy fields. This finding suggested that humans might have removed weeds for rice cultivation during the Neolithic period. Thus, pollen analysis in association with phytolith analysis was a promising method for identifying ancient paddy fields.

The lower Yangtze River area has for long been thought of as an important center of early rice domestication (Crawford and Shen, 1998; Malone, 1998; Zhao, 1998; Mannion, 1999). Although fossil rice phytoliths preserved in the late glacial sediments of Poyang Lake, southern China (Jiang and Piperno, 1999) and the East China Sea (Lu et al., 2002) suggest that rice cultivation in this area might have started as early as about 14000 years BP, direct evidence of a very early origin of rice agriculture is scarce. During archaeological excavations that had been carried out since 1998 at the Chuodun site in the k u i g r ~ cR i\ C'I' Dclltd, lliv Nujiug Museurn, tlitl Suzliou MuscuIIi, arid thc liistitutc of Soil Scic'ncc, Chinese Academy of Science?, discovered a number of paddy field remnants dating back to 4500 years BC. During the sixth excavation in November 2003, a total of 22 paddy fields, numbered S2-46, were found in Unit VI of this site within an area of 300 m2. These small fields with areas of 1-10 m2 were reclaimed in the lowland during the Majiabang Cultures (5500-3800 yeass BC). To facilitate irrigation, these fields were usually connected to each other with channels, ponds, and wells where living utensils, such as pottery vessels, pots, and jars, were found. In addition, a wealth of charred rice grains werewashed and sorted from ash layers. According to the latest archaeological reports, the shape of these rice grain remnants was very different from that of the wild rice (Tang, 2003). Studies on the ancient paddy fields at the Chuodun site are of great importance for unraveling the history of rice domestication in East Asia. This study aimed to investigate the pollen and phytolith assemblages of two soil profiles from the ancient paddy fields of the Chuodun site.

Although analyses based on the structure and morphology of the soil pertaining to the Majiabang Cultures provided no evidence of aiicierit paddy fields, research based oil pliytulith analysis of the PO1 profile suggested that paddy fields were present. According to palynological studies, the pollen spectra of the ancient paddy fields were similar to those of the modern paddy fields. Gramineae dominated the pollen assemblage with low frequency of the aquatic herb pollen, a phenomenon that appeared at other archaeological sites, such as the Longqiuzhuang site. Humans might have removed the weeds in the paddy fields during the Neolithic period. Therefore, it is believed that Gramineae and aquatic herbs, together with phytolith analysis, can be used as indicators of ancient paddy fields at archaeological sites in the Yangtze River Delta.