Fire and flood management of coastal swamp enabled first rice paddy cultivation in east China

Abstract

The adoption of cereal cultivation was one of the most important cultural processes in history, marking the transition from hunting and gathering by Mesolithic foragers to the food-producing economy of Neolithic farmers. In the Lower Yangtze region of China, a centre of rice domestication, the timing and system of initial rice cultivation remain unclear. Here we report detailed evidence from Kuahuqiao that reveals the precise cultural and environmental context of rice cultivation at this earliest known Neolithic site in eastern China, 7,700 calibrated years before present (cal. yr bp). Pollen, algal, fungal spore and micro-charcoal data from sediments demonstrate that these Neolithic communities selected lowland swamps for their rice cultivation and settlement, using fire to clear alder-dominated wetland scrub and prepare the site for occupation, then to maintain wet grassland vegetation of paddy type. Regular flooding by slightly brackish water was probably controlled by 'bunding' to maintain crop yields. The site's exploitation ceased when it was overwhelmed by marine inundation 7,550 cal. yr bp. Our results establish that rice cultivation began in coastal wetlands of eastern China, an ecosystem vulnerable to coastal change but of high fertility and productivity, attractions maximized for about two centuries by sustained high levels of cultural management of the environment.

A map of rice genome variation reveals the origin of cultivated rice

“…Our genetic approach showed that the middle area of the Pearl River in Guangxi province, southern China, was probably the place of the first development of cultivated rice (Fig. 4b-d), although an archaeological finding had identified the Lower Yangtze region in eastern China as one of the centres of rice cultivation 14,15 . These results suggest a model in which japonica was first domesticated from Or-III in southern China, and was subsequently crossed to local wild rice in South East Asia and South Asia, thus generating indica after many cross-differentiation-selection cycles (Fig.…”

“…Despite the fact that rice is a major cereal and a model system for plant biology, the evolutionary origins and domestication processes of cultivated rice have long been debated. The puzzles about rice domestication include: (1) where the geographic origin of cultivated rice was, (2) which types of O. rufipogon served as its direct wild progenitor, and (3) whether the two subspecies of cultivated rice, indica and japonica, are derived from a single or multiple domestications.A wide range of genetic and archaeological studies have been carried out to examine the phylogenetic relationships of rice, and investigate the demographic history of rice domestication [10][11][12][13][14][15][16][17][18][19] . Molecular phylogenetic analyses indicated that indica and japonica originated independently 3,10,20 .…”

“…A wide range of genetic and archaeological studies have been carried out to examine the phylogenetic relationships of rice, and investigate the demographic history of rice domestication [10][11][12][13][14][15][16][17][18][19] . Molecular phylogenetic analyses indicated that indica and japonica originated independently 3,10,20 .…”

Response of rice cultivation to fluctuating sea level during the Mid-Holocene

“…As the ecology in the Yangtze Delta in the Mid-Holocene improved, rice cultivation became greatly developed [13,14,21]. However, the studies of the Tianluoshan site have also confirmed that rice cultivation was affected by sea level fluctuations.…”

The Checkered Prehistory of Rice Movement Southwards as a Domesticated Cereal—from the Yangzi to the Equator

“…Such fluctuations in the presence of rice might have reflected issues of availability and supply on the northern edge of its range. After Jiahu and Shangshan, further archaeological evidence for the intensification of rice exploitation comes from Kuahuqiao in northern Zhejiang (ZPICRA 2004;Zong et al 2007). Dating to c.6,000 BC, this site has yielded a waterlogged canoe, wooden paddles, foundations of pile dwellings, a small proportion of morphologically domesticated rice (most grains still have wild morphologies) that resembles the japonica subspecies, and a possibility of pig domestication .…”