The Origin and Development of Rice Cultivation

中国稻作起源的研究取得了新的成果。关于稻作起源，以往的认识认为稻作起源于距今5000年前的云南地区，而本研究揭示了稻作起源于长江中游流域尤其是湖南地区，稻作起源的年龄大于12岁，湖南省地处亚热带气候，然而，在冬季这一地区受到寒冷的侵袭是否带来降雪。结果表明，冬季寒冷的气候，特别是晚冰期的新仙女木期，导致了粮食危机。这一次粮食危机，或许就是民众转向修炼的重要因素。在此之后，随着气候的恶化，水稻种植在7000年、5000年和3000年前得到了扩大。这意味着气候恶化造成的粮食危机是稻米农业扩大和发展的重要因素之一。5000年前，长江下游良渚文化区、长江中游屈家岭文化区和长江上游昌都平原都发生了城市化。本研究对成都平原龙马古城遗址进行了发掘，明确了长轴1100 m、短轴600 m的巨型长方形城堡城墙建于公元前2500年，城墙是由以青冈栎和栎属为主的万年青阔叶林破坏而成。在这座设防的城镇中，有花园和运河的房屋，但我们无法找到墙内稻田的证据。这个城市化的城镇在公元前1000年因季风波动造成的气候恶化而衰落。

New results were obtained on the origin of rice cultivation in China. Previous knowledge about the origin of rice cultivation was that the rice cultivation began in Yunan district at 5000 years BP.However, this research project revealed the birth place of the rice cultivation was the middle basin of the the Yangtze Rive especially the area of Hunan province and that the age of the beginning of rice cultivation was older than 12,000 years BP.The Hunan Province is located in the subtropical climate, however, in winter this region is attacked by the cold whether bringing snow. Our results showed that this cold climate in winter, especially during the Younger Dryas in Late glacial period caused the food crisis. This food crisis might be the important element for the people to shift toward cultivation. After that time, the rice cultivation expanded at 7000,5000 and 3000 years BP when the climate deteriorated. This means that the food crisis caused by the climatic deterioration was one of the important elements for the expansion and development of rice agriculture. At 5000 years BP,the urbanization occurred at the Liangzhu cultural area in lower basin of the Yangtze River, at the Qujialing cultural area in middle basin of the Yangtze River and at the Changdu plain in the upper basin of the Yangtze River. In this research project, we excavated the Longmagucheng site in the Chengdu plain and cleard that the huge oblong castle wall 1100m in long axis and 600m in short axis was constucted at 2500BC.The wall was constructed by the destruction of the evergreen broad leafed forest mainly composed by Quercus Cyclobalanopsis and Castanoposis. Houses with garden and canals existed in this fortified town, however, we could not find out the evidence of rice paddy field inside of wall. This urbanized town was declined at 1000BC by the climatic deterioration which mainly caused by the fluctuation of the monsoon.