Expansion of Cropland Area and Formation of the Eastern Farming-Pastoral Ecotone in Northern China During the Twentieth Century
Total Page：16
File Type：pdf, Size：1020Kb
Reg Environ Change (2012) 12:923–934 DOI 10.1007/s10113-012-0306-5 ORIGINAL ARTICLE Expansion of cropland area and formation of the eastern farming-pastoral ecotone in northern China during the twentieth century Yu Ye • Xiuqi Fang Received: 5 January 2012 / Accepted: 27 March 2012 / Published online: 12 April 2012 Ó Springer-Verlag 2012 Abstract Land cover changes induced by historical processes during this period, finally resulting in the crea- cultivation in ecologically fragile areas involving important tion of the modern farming-pastoral ecotone pattern. issues such as environmental change, ecology, and human sustainability are particularly worthy of attention. This Keywords Land cover changes Á Historical cultivation Á paper reconstructs the spatial distribution of cultivated Ecologically fragile area Á Cultivation ratio contours areas at the county level in the eastern farming-pastoral ecotone of northern China for four time periods during the twentieth century. The paper also analyzes how the loca- Introduction tion of cultivation ratio contours of 15 and 30 %, repre- senting the boundaries of agricultural areas, have moved The impacts of human activities on ecosystems and land and the formation process of farming-pastoral ecotone cover are some of the most important causes of Earth system patterns during this period. The study concludes that the change (Steffen et al. 2004). From the beginning of the area and ratio of cultivated land fluctuations increased twentieth century, land cover change caused by human during the twentieth century. The boundaries of the culti- activity has become a global phenomenon accompanied by vation ratio contours of 15 and 30 % continually moved Earth system change (Chhabra et al. 2005). Within the west and north. Moving north took priority over the other framework of phase II of the International Geosphere–Bio- directions during the period of 1916–1940, when its center sphere Programme (GLP Science Plan and Implementation moved the farthest during the twentieth century, and the Strategy 2005), Global Land Projects take interactions boundaries primarily moved westward during 1940–1980 between ecosystem functioning and human social dynamics and northwestward during 1980–2000. The distance, as key processes. These projects study the alteration of direction, and extent of the movement of the cultivation ecosystems and natural landscapes by human activities, and boundaries are all related to agricultural area expansion they emphasize the interrelationships between decision making, ecosystem services, and global environmental change from different spatial scales (Steven 2008; Turner 2008; Damian 2008; Dolors et al. 2006). Research on the Y. Ye (&) Á X. Fang impact of land surface modifications on global climate School of Geography, Beijing Normal University, change, carbon budgets, ecosystem services and biodiver- Beijing 100875, China sity, human survival, and sustainable development is now e-mail: yeyuleaffi[email protected] actively discussed ‘‘hotspots’’ (Schneider and Eugster 2007; Y. Ye Richard et al. 2007; Shi et al. 2007; Turetta et al. 2008; Key Laboratory of Environment Change and Natural Disaster, Vineet and George 2008; Al-Adamat et al. 2007; Kamoni Ministry of Education, BNU, Beijing 100875, China et al. 2007; Lisa et al. 2007; Erle et al. 2006; Helmut 2008). The farming-pastoral ecotone in northern China is X. Fang Institute of Geographic Sciences and Natural Resources located in the transitional region between the westerly Research, CAS, Beijing 100101, China inland climate and the monsoon climate. Affected by the 123 924 Y. Ye, X. Fang terminal effects of the monsoon, a large precipitation var- and historical documents (Wu 1999; Zou 1999; Han 2005). iation occurs. The environment is extraordinarily fragile Some scholars have analyzed the change of the farming- and sensitive in this area, making the land’s carrying pastoral ecotone and its social effect under the background capacity relatively small. Land cover change induced by of climate change (Zhang et al. 1997; Zhang 1996; Man historical land reclamation, involving important issues such et al. 2000). Some studies have focused on the historical as environment change, ecosystem recovery, and even agricultural reclamation and land use changes in the north human survival, is particularly worthy of attention. On the to the Yanshan Mountain, Kerqin, and ReChaSui regions one hand, because the ecotone is more sensitive to climate (Deng 2005; Wulantuya 1999; Tian 2005). Other studies change, it has the typical land use pattern of an interlaced have considered the environmental effects of historical farming-pastoral distribution. Basic human survival in this human land use activities (Yang and Suo 1996; Wang region has been satisfied by production activities such as 2000) or modern landscape changes under the background cultivation or pasturing. Land cover-type changes have also of climate change in this region (Liu and Gao 2008; Liu affected the carbon cycle, the water–heat balance, and the et al. 2007; Chen et al. 2006; Wang et al. 1999). local atmospheric circulations of the land surface system. This article reconstructs the cropland area and cultiva- On the other hand, land reclamation in ecologically fragile tion ratio at the county level in different time periods in the areas often aggravates local environmental problems. twentieth century in the eastern farming-pastoral ecotone in Historically, for example, this belt once had splendid northern China. The study analyzes the spatial movement periods when inland lakes developed here (Zhang 1992; of cultivation ratio contours, which represent certain Zhang and Fang 2012). Given the effects of environmental boundaries. The article also explores the formation process change and human cultivation activities, however, most of of current farming-pastoral interlaced patterns. the lakes either shrank or dried up completely. Fluvial and lacustrine sediments exposed to land surfaces suffered from strong, windy erosion and became sandy, barren land. Data sources and methods Extensive cultivation of rotation tillage in historical periods also had destructive effects on soil and vegetation, resulting Research area in the rapid decrease of grassland areas and desertification. Some researches have demonstrated that the ebb and Drawing on the widely adopted definitions of the farming- flow of two production modes in the farming-pastoral pastoral ecotone, which is determined by agricultural cli- ecotone at different time scales was one way humans mate conditions and land uses according to some scholars’ adapted to the climate, resulting in profound environmental researches (Zhang 1992, 1996; Zhang and Fang 2012; Zhao changes (Zhang et al. 1997; Fang 1999; Fang et al. 2002). 1953; Wang and Shi 1988; Zhao et al. 2002), we selected During the past 300 years, especially in the late Qing the east edge of the Inner Mongolian Plateau and the region Dynasty, land use change induced by human cultivation along the Great Wall as our research area. The annual was likely an important factor promoting the formation of precipitation in this area is 300–450 mm, the aridity index the farming-pastoral ecotone in northern China. In the is 1–2, and the cultivation ratios are approximately eastern part, large numbers of Han farmers crossed the 15–35 %. Also called the Eastern farming-pastoral ecotone Great Wall to engage in farming and grazing production in northern China, this area is located east of the boundary under government policies that encouraged reclamation at of Erlianhaote City, Jinin County. The area includes 29 that time. During this period, the farming-pastoral ecotone counties (or cities) in southeastern Inner Mongolia, 22 rapidly spread into ecologically fragile areas characterized counties (or cities) in the west of three provinces in by unstable climates, frequent droughts, and strong wind- Northeast China (Liaoning province, Jilin province, and and sand-flow activities. The result was the rapid devel- Heilongjiang province), and 17 counties (or cities) in opment of wind erosion of croplands and subsequent northern Hebei Province (Fig. 1). desertification. Considering this phenomenon in recent historical periods provides clues to understanding today’s Data sources ecological environmental problems. Many researchers have discussed several historical for- Cropland data from 1916 that include governmental sta- mation processes of this ecotone. Nevertheless, how the tistical data sourced from The Fifth Agricultural and modern eastern farming-pastoral ecotone came into being Commercial Statistical Table in the fifth year of the remains unclear. Some scholars have described the evolu- Republic of China (Statistics Faculty of General Affairs tionary process of the farming-pastoral ecotone in northern Office in the Department of Agriculture and Commerce China and its boundaries in different dynasties since the 1919) were used along with survey data by the Manchu Holocene Optimum period using archeological materials Railway Company sourced from The Encyclopedia of 123 Expansion of cropland area and formation 925 Legend 125 FGTZ Province 120 Elevation(m) 50 -100-0 130 0-100 100-150 150-200 200-250 250-300 300-400 400-500 500-600 600-800 45 800-1000 1000-1200 1200-1500 115 1500-2000 2000-3000 Legend Research area 130 40 120 0 125 250 375 500 0 750 1,500 2,250 3,000 Km 115 Km Fig. 1 Location of the eastern farming-pastoral ecotone in northern China. CA county administration; FGTZ farming-pastoral ecotone Manchu and Mongolia