Feedbacks between agriculture and climate: An illustration of the potential unintended consequences of human land use activities
Feedbacks between agriculture and climate: An illustration of the potential unintended consequences of human land use activities
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DOI：
10.1016/j.gloplacha.2005.10.005
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发表时间：
2006-11
期刊：
影响因子：
--
通讯作者：
N. Ramankutty;C. Delire;P. K. Snyder
中科院分区：
文献类型：
--
作者：
N. Ramankutty;C. Delire;P. K. Snyder
农业极大地改变了地球的面貌。特别是，农田已经取代了全球陆地表面大片区域的自然植被，今天覆盖了大约1800万平方公里的陆地表面。为了种植农作物，人类利用了气候提供的资源--最适宜的温度和降水。然而，开垦土地以建立农田可能导致了无意中的气候变化。这种反馈可能反过来改变了土地种植农作物的适宜性。在这项敏感性研究中，我们使用了土地覆盖数据集、数值模型和农田适宜性分析相结合的方法，来估计农田取代自然植被可能改变土地耕作适宜性的程度。我们发现，农田适宜性的全球变化可能相当小，但农田适宜性的区域变化可能已经发生。我们的理论研究表明，加拿大、东欧、前苏联、印度北部和中国的适宜性发生了重大变化。虽然这项研究表明的变化的幅度、符号和空间模式可能是我们特定的模型和实验设计的产物，但我们的研究说明了人类活动对陆地的潜在无意后果。此外，它还提供了一种评估陆地上人类活动引起的气候变化如何改变生态系统为人类提供的多种服务的方法。
Agriculture has significantly transformed the face of the planet. In particular, croplands have replaced natural vegetation over large areas of the global land surface, covering around 18 million km2of the land surface today. To grow crops, humans have taken advantage of the resource provided by climate — optimum temperature and precipitation. However, the clearing of land for establishing croplands might have resulted in an inadvertent change in the climate. This feedback might, in turn, have altered the suitability of land for growing crops. In this sensitivity study, we used a combination of land cover data sets, numerical models, and cropland suitability analysis, to estimate the degree to which the replacement of natural vegetation by croplands might have altered the land suitability for cultivation. We found that the global changes in cropland suitability are likely to have been fairly small, however large regional changes in cropland suitability might have occurred. Our theoretical study showed that major changes in suitability occurred in Canada, Eastern Europe, the Former Soviet Union, northern India, and China. Although the magnitude, sign, and spatial patterns of change indicated by this study may be an artifact of our particular model and experimental design, our study is illustrative of the potential inadvertent consequences of human activities on the land. Moreover, it offers a methodology for evaluating how climate changes due to human activities on the land may alter the multiple services offered by ecosystems to human beings.