The consequences of urban land transformation on net primary productivity in the United States
The consequences of urban land transformation on net primary productivity in the United States
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DOI：
10.1016/j.rse.2003.10.015
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发表时间：
2004-02-29
影响因子：
13.5
通讯作者：
Ricketts, T
中科院分区：
文献类型：
--
作者：
Imhoff, ML;Bounoua, L;Ricketts, T
我们使用来自两颗卫星和一个陆地碳模型的数据来量化城市化对美国碳循环和粮食生产的影响，这是净初级生产力（NPP）降低的结果。我们的研究结果表明，城市化发生在最肥沃的土地上，因此对NPP产生了不成比例的整体负面影响。美国城市土地改造使光合作用固定的碳量每年减少0.04 pg，相当于城市建设前投入的1.6%。这一减少足以抵消土地转为农业用途所带来的1.8%的收益，尽管城市化覆盖的面积不到美国土地面积的3%，而农业用地接近总土地面积的29%。在地方和区域尺度上，城市化增加了资源有限地区的净初级生产力，通过局部变暖，“城市热”有助于延长寒冷地区的生长季节。就生物可利用能源而言，仅因农业用地城市化造成的NPP损失就相当于1650万人或约占美国人口6%的热量需求。(C)2004年爱思唯尔公司All rights reserved.
We use data from two satellites and a terrestrial carbon model to quantify the impact of urbanization on the carbon cycle and food production in the US as a result of reduced net primary productivity (NPP). Our results show that urbanization is taking place on the most fertile lands and hence has a disproportionately large overall negative impact on NPP. Urban land transformation in the US has reduced the amount of carbon fixed through photosynthesis by 0.04 pg per year or 1.6% of the pre-urban input. The reduction is enough to offset the 1.8% gain made by the conversion of land to agricultural use, even though urbanization covers an area less than 3% of the land surface in the US and agricultural lands approach 29% of the total land area. At local and regional scales, urbanization increases NPP in resource-limited regions and through localized warming "urban heat" contributes to the extension of the growing season in cold regions. In terms of biologically available energy, the loss of NPP due to urbanization of agricultural lands alone is equivalent to the caloric requirement of 16.5 million people, or about 6% of the US population. (C) 2004 Elsevier Inc. All rights reserved.