Photosynthetic Carbon Isotope Discrimination and Effects on Daytime NEE Partitioning in a Subtropical Mixed Conifer Plantation

doi:10.1016/j.agrformet.2019.03.027

	Photosynthetic Carbon Isotope Discrimination and Effects on Daytime NEE Partitioning in a Subtropical Mixed Conifer Plantation
	Chen, Changhua 1,2; Wei, Jie 1; Wen, Xuefa 1,2; Sun, Xiaomin 1,2; Guo, Qingjun 2,3
刊名	AGRICULTURAL AND FOREST METEOROLOGY
	2019-07-15
卷号	272 页码:143-155
关键词	Carbon isotope Photosynthetic discrimination Isotopic flux partitioning Isotope ratio infrared spectroscopy Eddy covariance
ISSN号	0168-1923
DOI	10.1016/j.agrformet.2019.03.027
通讯作者	Wen, Xuefa(wenxf@igsnrr.ac.cn) ; Sun, Xiaomin(sunxm@igsnrr.ac.cn)
英文摘要	Isoflux-based isotopic flux partitioning (isoflux-based IFP) separates net ecosystem exchange flux (NEE) into net photosynthesis (F-A) and nonfoliar respiration (F-NR), and avoids the spurious correlation of component fluxes found in statistical flux partitioning. Canopy photosynthetic discrimination (Delta(canopy)) is a key variable in isoflux-based IFP, but it ignores diffusional and respiratory fractionations, with unclear consequences for isoflux-based IFP. We used three versions of the Farquhar model (Delta(classical), Delta(diffusion), and Delta(simple)) to estimate Delta(canopy) based on in-situ measurements of CO2 isotope ratios and flux during a dry period (I; DOY 205-219, 2015) and a humid period (II; DOY 285-299, 2015) in a subtropical mixed conifer plantation. We found no significant differences in Delta(canopy) between Delta(classical) and Delta(diffusion) which ignored respiratory fractionations during photorespiration and dark respiration. The average differences between Delta(classical) and Delta(simple), which ignored respiratory and diffusional fractionations across the leaf boundary layer and mesophyll, were 2.88 +/- 2.34 parts per thousand and 2.16 +/- 2.18 parts per thousand for the two periods. Similarly, there were no significant differences in F-A with isoflux-based IFP using Delta(classical) and Delta(diffusion) to obtain Delta(canopy); F-A using Delta(simple) was 102 and 117% higher than that using Delta(classical) for the dry and humid periods. Moreover, using Delta(classical) and Delta(diffusion) captured the reduction in daytime respiration during the dry period; this may be associated with the Kok effect and seasonal drought. Sensitivity analysis showed that changes in mesophyll and stomatal conductances of +/- 50% resulted in > 15% change in F-A. Diffusional fractionations in mesophyll and stoma are critical limitations to isoflux-based IFP, while photorespiratory fractionation is an unignorable component of Delta(canopy) and isoflux-based IFP.
资助项目	National Key Research and Development Program of China[2017YFC0503904] ; National Natural Science Foundation of China[41830860] ; National Natural Science Foundation of China[31470500] ; National Natural Science Foundation of China[41671257]
WOS关键词	MESOPHYLL CONDUCTANCE ; TEMPERATURE RESPONSE ; C-13 DISCRIMINATION ; ECOSYSTEM EXCHANGE ; GAS-EXCHANGE ; CO2 EXCHANGE ; DIURNAL-VARIATION ; FAGUS-SYLVATICA ; REGIONAL SCALES ; WATER-VAPOR
WOS研究方向	Agriculture ; Forestry ; Meteorology & Atmospheric Sciences
语种	英语
出版者	ELSEVIER SCIENCE BV
WOS记录号	WOS:000469158400013
资助机构	National Key Research and Development Program of China ; National Natural Science Foundation of China
内容类型	期刊论文
源URL	[http://ir.igsnrr.ac.cn/handle/311030/58960]
专题	中国科学院地理科学与资源研究所
通讯作者	Wen, Xuefa; Sun, Xiaomin
作者单位	1.Chinese Acad Sci, Inst Geog Sci & Nat Resources Res, Key Lab Ecosyst Network Observat & Modelling, Beijing 100101, Peoples R China 2.Univ Chinese Acad Sci, Coll Resources & Environm, Beijing 100190, Peoples R China 3.Chinese Acad Sci, Inst Geog Sci & Nat Resources Res, Ctr Environm Remediat, Beijing 100101, Peoples R China
推荐引用方式 GB/T 7714	Chen, Changhua,Wei, Jie,Wen, Xuefa,et al. Photosynthetic Carbon Isotope Discrimination and Effects on Daytime NEE Partitioning in a Subtropical Mixed Conifer Plantation[J]. AGRICULTURAL AND FOREST METEOROLOGY,2019,272:143-155.
APA	Chen, Changhua,Wei, Jie,Wen, Xuefa,Sun, Xiaomin,&Guo, Qingjun.(2019).Photosynthetic Carbon Isotope Discrimination and Effects on Daytime NEE Partitioning in a Subtropical Mixed Conifer Plantation.AGRICULTURAL AND FOREST METEOROLOGY,272,143-155.
MLA	Chen, Changhua,et al."Photosynthetic Carbon Isotope Discrimination and Effects on Daytime NEE Partitioning in a Subtropical Mixed Conifer Plantation".AGRICULTURAL AND FOREST METEOROLOGY 272(2019):143-155.