应用生态学报2017，Vol.28Issue(7)：2164-2170,7.DOI:10.13287/j.1001-9332.201707.014
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
Variations and determinants of CO2 concentration and δ13C in Platycladus orientalis plantation in Beijing mountainous area, China
摘要
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.关键词
稳定同位素/光合作用/呼吸作用/环境因子Key words
stable isotope/photosynthesis/respiration/environmental factors引用本文复制引用
李瀚之,余新晓,贾国栋,赵娜,刘自强,路伟伟,张永娥..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[J].应用生态学报,2017,28(7):2164-2170,7.基金项目
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 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). （41430747,41401013）
