Research Of Cropland Expansion Process In Typical Nortern China During The Qing Dynasty

Land reclamation is the foundation for agriculture, in the agricultural society, agricultural activity is the main way to change land use and land cover, so historical land-use and land-cover changes caused by human activities during the last three centuries have been regarded as one of the five key frame issues in the LUCC project. Currently, there are two global historical land use datasets, generally referred as the "RF datasets" and "HYDE database", but at the national level, these global datasets are widely doubted with coarse resolution and inevitable errors. China had its population boom ever during the prime Qing dynasty, which prompt the expansion of cultivated land, and reduction of the forest land, grassland. With the influence of the humanities and natural factors, such as population migration, land use of northern China had dramatically changed, therefore northern China is the key area of history LUCC study. The analysis of land developing process and the characteristics of the space and time would provide important basis for reconstruction of the historical land use data and spatial inversion, thus, the research of land reclamation process makes great significance for the land use cover change in northern China during the Qing dynasty.This paper grounded itself on China’s historical records and related research achievements, and reconstructed land reclamation process under the Qing dynasty boundaries from 1661 to 1911 of Inner Mongolia, the northeast China and Xinjiang, using a variety of methods based on resources and population, such as policy analysis, comparison, reclamation trend examination, administrative boundaries, etc. Then we analyzed northern China’s cropland growth process, regional changes as well as the space differences of land expansion and came up with the following conclusions:Firstly, cultivated land development in typical northern China had experienced different stages. Land reclamation of Northeast China and Inner Mongolia was divided into the forbidden reclamation phase and reclamation phase. During the period of forbidden reclamation, mainland farmers immigrated into the northeast China and Inner Mongolia privately, developing scattered land; during the reclamation period, the large-scale immigration promoted the development of wide range land. Land reclamation of Xinjiang in the Qing dynasty had experienced five stages.Secondly, affected by human and natural factors, typical northern China’s cultivated land expansion had obvious spatial difference in the Qing dynasty. Land reclamation of Inner Mongolia started from south to north, from east to west; the northeast China’s land reclamation developed from south to north, Fengtian is the earliest place, of which land was reclaimed, but most land of Jilin and Heilongjiang was exploited at the end of the Qing dynasty; the development of Xinjiang’s farmland was from east to west, from north to south, and in the wasteland type, the development of soldier reclamation was earlier than that of immigrant reclamation.Thirdly, cultivated land exposion of northern China in the Qing dynasty was characterized by northern agro-pastoral ecotone changes. Modern northern agro-pastoral ecotone pattern took shape in the Qing dynasty, when Mongolian land appeared large-scale agricultural activities. During the last 300 years, northern agro-pastoral ecotone had moved westward and northward from the Great Wall to prairie hinterland; there were two big leaps for the northern agro-pastoral ecotone to go northward remarkably. The first one occurred during the reign of Qian Long, and moved northward about 100km; The second one happened at the end of the Qing dynasty when large scale of population flew to Mongolia encouraged by the policy. There are time and regional differences in the expansion of northern agro-pastoral during the Qing dynasty. Land reclamation in the east and middle part was earlier than that in the west, and the eastern part moved northward about 700km, and the western part about 100km, which reflected the restrictions of the natural conditions on land development.Fourthly, from the early year of Qing dynasty to 1900, the Qing government banned reclamation in northeast and Inner Mongolia, but there are farmers privately immigrating to reclaim land, which indicated that implementation and enforcement of policy would be affected by contradiction between human and resources, which caused by natural disasters, wars and population growth. In the condition of difficult to survive, the Qing government had to relax management, and acquiesce in the immigration.