大气气溶胶对北京杨树人工林生态系统生产力的影响

Abstract

PDF HTML阅读 XML下载 导出引用 引用提醒 大气气溶胶对北京杨树人工林生态系统生产力的影响 DOI: 10.5846/stxb202005281383 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金项目（31872711） Effects of atmospheric aerosols on the ecosystem productivity of a poplar plantation in Beijing Author: Affiliation: Fund Project: Impact Mechanisms of Atmospheric Aerosols on Forest Ecosystem Carbon and Water Coupling 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:大气气溶胶可以影响到达地面的太阳辐射，进而影响植物光合作用和生态系统生产力，乃至区域上的碳收支。为探究北京地区气溶胶对杨树人工林生态系统生产力的影响，利用2006-2009年北京大气气溶胶数据结合北京大兴杨树人工林涡度相关系统监测的辐射、碳通量等数据，分析了气溶胶对散射辐射、光能利用效率（LUE）、生态系统初级生产力（GPP）的影响，并利用通径分析方法探究了气溶胶和生态环境因子对GPP的直接和间接影响。结果表明，北京市气溶胶光学厚度（AOD）具有明显的季节变化特征：春、夏两季大于秋、冬季，夏季气溶胶光化学厚度最大。大气气溶胶显著影响了地表辐射组分以及温度、湿度环境因子，随着AOD从0增大到3，总辐射减小了43.63%，散射辐射增加132.26%，散射辐射比例增大了2.55倍，而相对湿度增大48.52%，日温差增大3℃左右。当生态系统受水分胁迫时，气溶胶对生态系统生产力无显著影响，当生态系统处于非水分胁迫时，杨树人工林生态系统光能利用效率和生产力随着气溶胶浓度增大先增大后减小，当AOD为1.0-1.6时，GPP维持在较高的水平，当AOD>2.5时，GPP显著减小且小于背景气溶胶（AOD<0.4）的GPP。通径分析表明，水分胁迫条件下，气溶胶对杨树人工林生态系统生产力的间接影响很小；非水分条件下，散射辐射对生态系统生产力影响最大，气溶胶可以通过增大散射光施肥效应来增大生态系统生产力。不同的水分条件下气溶胶对杨树人工林生态系统的影响不同，非水分胁迫条件下适宜的气溶胶增大杨树人工林生态系统的生产力，严重的气溶胶污染（AOD>1.5）则导致杨树生态系统生产力下降。 Abstract:Atmospheric aerosols can affect the solar radiation reaching the ground, which in turn affects plant photosynthesis and ecosystem productivity, and even regional carbon balance. With the further development of global change, atmospheric aerosols pollution and drought stress coexist in some regions, and the high frequency and long duration of drought stress may lead to the conversion of ecosystems from carbon sinks to carbon sources. However, little is known about whether atmospheric aerosols can increase ecosystem productivity when the ecosystem are under water stress. Therefore, in this study we investigated the effects of atmospheric aerosols on diffuse radiation, light utilization efficiency (LUE) and the gross primary productivity (GPP) of poplar plantation under different water conditions in Beijing. The direct and indirect effects of atmospheric aerosols and ecological factors on GPP were explored by the path analysis method, which used the atmospheric aerosols data from 2006 to 2009 and combined with the radiation and carbon flux data monitored by Eddy covariance system in Daxing poplar in Beijing. The results showed that Beijing's atmospheric optical depth (AOD) had obviously seasonal change characteristics. The AOD was higher in spring and summer than that in autumn and winter, and the AOD was the largest in summer. The atmospheric aerosols had significant effects on radiation and micrometeorological factors. With the increase of AOD from 0 to 3, photosynthetically active radiation (PAR) decreased by 43.63%, diffuse radiation increased by 170%, and the fraction of diffuse radiation increased by 2.55 times, while the relative humidity increased by 48.52% and daily temperature difference increased about 3℃. When the ecosystem was under moisture stress, the atmospheric aerosols had no effect on the GPP. When the ecosystem was under non-moisture stress, the LUE and GPP of poplar plantation ecosystem increased first and then decreased with the increase of aerosol concentration. When the AOD was 1.0-1.6, the GPP was maintained at a high level. When the AOD>2.5, the GPP significantly decreased and less than the GPP of the background atmospheric aerosol (AOD<0.4). The path analysis showed that the indirect effect of atmospheric aerosols on ecosystem productivity of poplar plantation was not significant under water stress, the diffuse radiation had the greatest influence on the GPP, and the atmospheric aerosols could increase the ecosystem productivity by increasing diffuse fertilization effect under non-moisture stress. Overall, the atmospheric aerosols had different effects on poplar plantation ecosystem under different water conditions. The suitable atmospheric aerosols could increase the productivity of poplar plantation ecosystems, while severe atmospheric aerosols pollution (AOD>1.5) led to a decrease in poplar ecosystem productivity under non-water stress conditions. 参考文献 相似文献 引证文献