生态、农业与政治:环境史视域下汉代朔方郡的历史演变

Ecology,Agriculture and Politics:Historical Evolution of Shuofang Commandery of the Han Dynasty in the Perspective of Environmental History

朔方郡是汉代北方边疆主要的屯田区之一,地处干旱至半干旱地区的过渡地带,生态脆弱,其农业社会的发展与衰落均体现出人类与环境之间的复杂互动。借助黄河和湖泊水源,汉政府将朔方作为“屯田实边”的据点,引导大量人口迁入,发展旱作灌溉农业。但大规模密集型农业生产和农耕定居的生活方式消耗自然资源,影响原生植被。西汉时期,朔方地区还承担着为内附匈奴部族生产、输送粮食的任务,因而加剧了区域生态压力。人类的破坏与自然因素叠加,导致朔方垦区土壤沙漠化进程加快。东汉初期气候转向干冷,北方政局动荡,大批农耕人口弃垦南迁,荒地在风蚀作用下逐渐被流沙覆盖,朔方郡就此衰落。生态条件、农业活动与政治导向的交互,决定了汉代朔方区域社会的兴衰,而环境史的视角能够揭示生态因素在历史研究中的重要作用,有助于拓宽对汉代屯田史的认知。

Shuofang Commandery was one of the major army farm colonies on the northern frontier of the Han dynasty.It was located in the arid and semi-arid area where the ecological system was highly fragile.The development and decline of the agricultural society in Shuofang demonstrated a complex interaction between human society and the environment.Using water from the Yellow River and lakes,the Han government constructed Shuofang as a stronghold for garrison troops and farmers.It led a large number of people to move here and develop the irrigation agriculture.However,large-scale intensive farming and a settled agrarian lifestyle required massive natural resources and damaged the vegetation cover of this area.During the Western Han period,Shuofang also played a role in providing and transferring grains to the affiliated Xiongnu tribes,which further intensified the regional ecological pressure.In the early Eastern Han Dynasty,the climate became dry and cold while the north was caught in a political turmoil,which led to the southward migration of a large number of the farming population and the desertification of the land under the erosion of wind.The interaction of ecological conditions,agricultural activities and political orientation determined the rise and fall of Shuofang region in the Han dynasty,and the perspective of environmental history can reveal the important role of ecological factors in historical research,and contribute to broadening people's cognition of the history of army farm colonies in the Han dynasty.