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应用生态学报 ›› 2017, Vol. 28 ›› Issue (7): 2164-2170.doi: 10.13287/j.1001-9332.201707.014

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北京山区侧柏人工林内CO2浓度及其δ13C值变化特征和影响因子

李瀚之, 余新晓*, 贾国栋, 赵娜, 刘自强, 路伟伟, 张永娥   

  1. 北京林业大学, 北京 100083
  • 收稿日期:2016-11-03 修回日期:2017-04-09 发布日期:2017-07-18
  • 通讯作者: *mail:yuxinxiao111@163.com
  • 作者简介:李瀚之,男,1990年生,博士.主要从事土壤侵蚀与森林生态研究.E-mail:lhz123950@163.com
  • 基金资助:
    本文由国家自然科学基金重点项目(41430747,41401013)和科技创新服务能力建设-协同创新中心项目(CEFF-PXM2016_014207_000038)资助

Variations and determinants of CO2 concentration and δ13C in Platycladus orientalis plantation in Beijing mountainous area, China

LI Han-zhi, YU Xin-xiao*, JIA Guo-dong, ZHAO Na, LIU Zi-qiang, LU Wei-wei, ZHANG Yong-e   

  1. Beijing Forestry University, Beijing 100083, China
  • Received:2016-11-03 Revised:2017-04-09 Published:2017-07-18
  • Contact: *mail:yuxinxiao111@163.com
  • Supported by:
    This work was supported by the National Natural Science Foundation of China (41430747, 41401013) and grants from the Beijing Municipal Education Commission (CEFF-PXM2016_014207_000038).

摘要: 本研究采用离轴积分腔输出光谱技术对北京山区侧柏人工林进行了大气CO2浓度及其δ13C值的原位观测,在半小时尺度上对比了林内不同高度处大气CO2浓度及其δ13C值的差异,并探究其对气象因子的响应.结果表明: 林内CO2浓度自日出后经历先降低后升高的变化趋势,最低值出现在16:00—16:30,浓度为352.5 μmol·mol-1,最大值出现在5:00左右,达到402.0 μmol·mol-1,其δ13C值变化趋势微弱且较为复杂,呈现出近地层先降低后升高、林冠层先升高后降低的趋势;研究日期内,林内CO2浓度随高度的升高而降低,林内0、2、5、8、12.5和18 m处的日均值为386.5、369.9、368.2、367.8、367.9和367.9 μmol·mol-113C值呈现出随高度升高而升高的趋势,林内0、2、5、8、12.5和18 m处的日均值为-16.0‰、-13.7‰、-13.5‰、-13.5‰、-13.1‰和-13.3‰;逐步回归分析表明,温度和湿度是影响林内大气CO2浓度及δ13C值的主要因子,饱和蒸汽压差(VPD)可以影响林内CO2浓度变化,风速可以影响林冠层CO2浓度变化,而土壤含水率、电导率和地面净辐射则是影响近地层CO2浓度及δ13C值的环境因子.这些环境因子通过增强或减弱生态系统内光合作用和呼吸作用来影响林内CO2浓度及其δ13C值的变化.

Abstract: This research employed off-axis integrated cavity output spectroscopy technique to observe CO2 concentration and δ13C values of planted Platycladus orientalis in Beijing mountainous area. We compared the variation between CO2 concentration and δ13C values in the plantation at different heights observed by every 0.5 h to explore how the CO2 concentration and δ13C values responded to the meteorological factors. The results showed that the CO2 concentration showed the pattern of “first decreased and then increased” after sunrise. The lowest value (352.5 μmol·mol-1) appeared at 16:00-16:30, while the maximum value (402.0 μmol·mol-1) was observed at about 5:00. However, the change of δ13C value was not significant and regular, which increased firstly and then decreased in the surface layer while opposite for the canopy. Atmospheric CO2 concentration decreased with the increasing height. In the height of 0, 2, 5, 8, 12.5 and 18 m, the average daily value was 386.5, 369.9, 368.2, 367.8, 367.9 and 367.9 μmol·mol-1, respectively. In contrast, the δ13C values tended to rise correspondingly with height with the average daily value being -16.0‰, -13.7‰, -13.5‰, -13.5‰, -13.1‰ and -13.3% at 0, 2, 5, 8, 12.5 and 18 m, respectively. The stepwise regression analysis showed that temperature and humidity were the main factors for the changes of atmospheric CO2 concentration and δ13C values. The saturated vapor pressure difference (VPD) affected the concentration of CO2 in the forest and wind speed could affect it on the canopy. However, soil moisture, soil electric conductivity and net solar radiation affected the CO2 concentration and δ13C values in surface layer. All these environmental factors influenced CO2 concentration and δ13C values through their influences on the photosynthesis and respiration.