Agricultural landscape change in China's Yangtze Delta, 1942–2002: A case study
Agricultural landscape change in China's Yangtze Delta, 1942–2002: A case study
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DOI：
10.1016/j.agee.2008.11.008
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发表时间：
2009-02
期刊：
影响因子：
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通讯作者：
Junxi Wu;Xu Cheng;Hongan Xiao;Hongqing Wang;L. Yang;Erle C. Ellis
中科院分区：
文献类型：
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作者：
Junxi Wu;Xu Cheng;Hongan Xiao;Hongqing Wang;L. Yang;Erle C. Ellis
在过去的60年里，中国古老的农业村庄景观已经被前所未有的农村政策，人口和农业技术的变化所改变。中国长江平原的村落景观是世界上最古老、人口最密集、管理最集中的景观之一，近几十年来经历了极其迅速的发展，导致传统村落景观结构发生了大规模的变化，主要是在精细的空间尺度上（<30 m）。在这里，我们调查的原因和后果，这些细尺度的变化，1942年至2002年，使用景观变化的案例研究在宜兴县的一个区域代表性的样本村庄景观。高分辨率绘图与通过访谈老年农民和档案来源获得的历史数据相结合，使用蒙特卡罗方法量化了不确定性。1942年已经密集的农业人口到2002年增加了约50%，这是伴随着土地管理的强化，导致53%的土地面积经历了景观类的重大变化。从1942年到2002年，稻田面积下降了22%，这与建筑面积净增加8%，水产养殖面积增加14%相结合，最令人惊讶的是，封闭式树冠木本植被的土地覆盖净增加了5%。这种变化大部分是由小规模的土地改造造成的，这种改造将较大的管理特征分割成较小的特征，这些特征包含了更广泛的管理实践，从而同时增加了景观的异质性和复杂性。人口增长、农业政策变化和以市场为导向的土地管理战略共同造成了这些重大的长期农业景观变化。通过对三个时间段的土地利用历史与细尺度局部景观转化过程的详细分析，本研究确定了生态上重要的景观变化的原因，也可能有助于表明世界上一些人口最稠密和生产力最高的农业景观的未来变化趋势。
Over the past 60 years, China's ancient agricultural village landscapes have been transformed by unprecedented changes in rural policy, population and agricultural technology. The village landscapes of China's Yangtze Plain are among the most ancient, densely populated and intensively managed in the world and have undergone extremely rapid development in recent decades, causing the wholesale transformation of traditional village landscape structure, primarily at fine spatial scales (< 30m). Here we investigate the causes and consequences of these fine-scale changes, 1942–2002, using a case study of landscape change within a regionally representative sample of village landscapes in Yixing County. High-resolution mapping was coupled with historical data obtained by interviews with elder farmers and archival sources, with uncertainties quantified using Monte Carlo methods. The already dense agricultural populations of 1942 had increased by about 50% by 2002, and this was accompanied by an intensification of land management that caused 53% of land area to undergo a substantial change in landscape class. Paddy area declined by 22% from 1942 to 2002, and this was coupled with an 8% net increase in built surfaces, a 14% increase in aquaculture surface, and most surprisingly, by a 5% net increase in land cover by closed canopy woody vegetation. Most of this change was caused by fine-scale land transformations that fragmented larger managed features into smaller features that incorporated a wider variety of management practices, thereby simultaneously increasing both landscape heterogeneity and complexity. Population growth, agricultural policy changes and market-oriented land management strategies combined to produce these significant long-term agricultural landscape changes. By coupling detailed analysis of fine-scale local landscape transformation processes with land use history across three time periods, this study identified the causes of ecologically significant landscape changes and may also help to indicate future change trends within some of the most densely populated and productive agricultural landscapes in the world.