...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Atmospheric environment >Temporal variability in the sources and fluxes of CO2 in a residential area in an evergreen subtropical city
【24h】

Temporal variability in the sources and fluxes of CO2 in a residential area in an evergreen subtropical city

机译：常绿亚热带城市居民区CO2排放源和通量的时间变化

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Measurements of CO2 fluxes in temperate climates have shown that urban areas are a net source of CO2 and that photosynthetic CO2 uptake is generally not sufficient to offset local CO2 emissions. However, little is known about the role of vegetation in cities where biogenic CO2 uptake is not limited to a 2-8 months growing season. This study used the eddy covariance technique to quantify the atmospheric CO2 fluxes over a period of 12 months in a residential area in subtropical Auckland, New Zealand, where the vegetation cover (surface cover fraction: 47%) is dominated by evergreen vegetation. Radiocarbon isotope measurements of CO2 were conducted at three different times of the day (06:00-09:00, 12:00-15:00, 01:00-04:00) for four consecutive weekdays in summer and winter to differentiate anthropogenic sources of CO2 (fossil fuel combustion) from biogenic sources (ecosystem respiration, combustion of biofuel/biomass). The results reveal previously unreported patterns for CO2 fluxes, with no seasonal variability and negative (net uptake) CO2 midday fluxes throughout the year, demonstrating photosynthetic uptake by the evergreen vegetation all year-round. The winter radiocarbon measurements showed that 85% of the CO2 during the morning rush hour was attributed to fossil fuel emissions, when wind was from residential areas. However, for all other time periods radiocarbon measurements showed that fossil fuel combustion was not a large source of CO2, suggesting that biogenic processes likely dominate CO2 fluxes at this residential site. Overall, our findings highlight the importance of vegetation in residential areas to mitigate local CO2 emissions, particularly in cities with a climate that allows evergreen vegetation to maintain high photosynthetic rates over winter. As urban areas grow, urban planners need to consider the role of urban greenspace to mitigate urban CO2 emissions. (C) 2016 Elsevier Ltd. All rights reserved.
机译：在温带气候中对CO2通量的测量表明，城市地区是CO2的净来源，光合作用的CO2吸收通常不足以抵消当地的CO2排放。但是，对于城市中生物作用二氧化碳的吸收不仅限于生长季节2-8个月的城市，植被的作用还知之甚少。这项研究使用涡度协方差技术对新西兰亚热带奥克兰居民区12个月内的大气CO2通量进行了量化，该地区的植被覆盖率（表面覆盖率：47％）以常绿植被为主。在夏季和冬季的连续四个工作日中，在一天的三个不同时间（06：00-09：00、12：00-15：00、01：00-04：00）进行了二氧化碳的放射性碳同位素测量，以区分人为活动来自生物源（生态系统呼吸，生物燃料/生物质燃烧）的CO2（化石燃料燃烧）来源。结果表明，以前没有报告过的CO2通量模式，没有季节性变化，全年中午的净CO2通量都为负，表明常年常绿植物全年光合吸收。冬季放射性碳的测量结果表明，在高峰时段，当风来自居民区时，二氧化碳的85％归因于化石燃料的排放。但是，对于所有其他时间段，放射性碳测量表明化石燃料燃烧不是CO2的主要来源，这表明生物过程可能主导了该居民点的CO2通量。总体而言，我们的发现强调了居住区植被对减轻局部CO2排放的重要性，尤其是在气候允许常绿植被在冬季保持高光合速率的城市中。随着城市面积的增长，城市规划者需要考虑城市绿地在减轻城市二氧化碳排放中的作用。 （C）2016 Elsevier Ltd.保留所有权利。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号