文献类型：期刊文献

英文题名：Early-latewood carbon isotope enhances the understanding of the relationship between tree biomass growth and forest-level carbon fluxes

作者：Jia, HanSen[1,2] Zhou, Yu[1,2] Zhang, JinSong[1,2] Sun, ShouJia[1,2] Meng, Ping[1,2]

第一作者：Jia, HanSen

通信作者：Zhang, JS[1]

机构：[1]Chinese Acad Forestry, Res Inst Forestry, Key Lab Tree Breeding & Cultivat State Forestry Ad, Beijing 100091, Peoples R China;[2]Nanjing Forestry Univ, Collaborat Innovat Ctr Sustainable Forestry Southe, Nanjing 210037, Peoples R China

年份：2022

卷号：315

外文期刊名：AGRICULTURAL AND FOREST METEOROLOGY

收录：;Scopus(收录号：2-s2.0-85122671760);WOS:【SCI-EXPANDED(收录号:WOS:000795819800003)】；

基金：This work was supported by a National Nonprofit Institute Research Grant of the Chinese Academy of Forestry (CAFYBB2018ZA001) and the Project of the Co-Innovation Center for Sustainable Forestry in Southern China of Nanjing Forestry University. The China Meteorological Data Service Center provided meteorological data.

语种：英文

外文关键词：Dendrochronology; Biomass increment; Eddy covariance; Carbon isotope; Carbon dynamics

摘要：Eddy covariance (EC) and biometric (based on tree diameter and tree ring measurements) methods are used extensively to estimate annual variability in forest productivity. Many previous studies obtained inconsistent findings between net ecosystem productivity (NEP) based on EC (NEPEC) and tree biomass growth based on biometric methods, partly because of delayed responses in trees due to temporary non-structural carbohydrate (NSC) storage. Direct measurement of the amount of NSCs stored in trees is challenging; however, using carbon (C) isotope ratios in different tree components is considered an indirect and effective alternative approach for assessing NSC dynamics. We measured stable C isotope ratios in earlywood (EW) and latewood (LW) of rings of 70 trees (categorized as 4-10, 10-20, and > 20 cm diameter at breast height [DBH]) to test relationships between trunk-growth NEPEC time series and annual tree biomass growth (based on tree ring width) in a young mixed forest in northern China over 13 years. Our results revealed a strong correlation (r = 0.691) between trunkgrowth NEPEC (March-August in a calendar year) and tree biomass growth. The change in correlation between current-year EW 813C and LW 813C of the previous year observed in trees with 10-20 cm DBH, which accounted for 51.8% of the total tree biomass growth, was consistent with the synchronicity of trunk-growth NEPEC and tree biomass growth. Colder early growing seasons, which significantly increase the reliance of early-season structural growth on stored labile C accumulated in the previous year, may lead to postponed tree biomass growth responses related to NEPEC. In conclusion, this approach, investigating C isotope analysis in EW and LW, helps elucidate the relationships between tree biomass growth and stand-level C fluxes in forest sites.