文献类型：期刊文献

英文题名：Partitioning oak woodland evapotranspiration in the rocky mountainous area of North China was disturbed by foreign vapor, as estimated based on non-steady-state O-18 isotopic composition

作者：Sun, ShouJia[1] Meng, Ping[1] Zhang, JinSong[1] Wan, Xianchong[2] Zheng, Ning[1] He, Chunxia[1]

第一作者：孙守家

通信作者：Meng, P[1]

机构：[1]Chinese Acad Forestry, Res Inst Forestry, State Key Lab Tree Genet & Breeding, Beijing 100091, Peoples R China;[2]Chinese Acad Forestry, Inst New Forestry Technol, Beijing 100091, Peoples R China

年份：2014

卷号：184

起止页码：36-47

外文期刊名：AGRICULTURAL AND FOREST METEOROLOGY

收录：;WOS:【SCI-EXPANDED(收录号:WOS:000328666400004)】；

基金：The study has been supported by Special Research of Forestry Public Welfare Industry (No. 201104009-04), the National Natural Science Foundation of China (No. 31000182) and CFERN&GENE Award Funds on Ecological Paper.

语种：英文

外文关键词：Quercus variabilis Blum; Stable isotope; Foreign vapor; Keeling plot; Evapotranspiration

摘要：In terrestrial ecosystems, partitioning ecosystem-scale evapotranspiration (ET) between plant transpiration and soil evaporation remains a technical challenge. In this paper, we used a newly-developed laser-based isotope analyzer (OA-ICOS) and the Keeling plot approach to partition ET components of a Quercus variabilis plantation in a lithoid hilly area of north China. The results showed that, on day-of-year (DOY) 254, 257, and 263, the modeled leaf water O-18 composition (delta(s)(L,b)) and observed leaf water O-18 composition (delta(L,b)) were in substantial agreement and had a significant linear correlation with coefficient of 0.96, indicating that Keeling plot approach and Graig-Gorden model can be used in portioning ET between plant transpiration and soil evaporation in a terrestrial forest ecosystem. Isotopic partition revealed that the percent contribution of transpiration to total ET increased from the morning, reached maximum values at noon, with maximum values of 91.19%, 86.30%, and 85.37% for DOY 254, 257, and 263, respectively, indicating the transpiration from Q. variabilis Blum contributed the most to the total ET in this forest ecosystem. On DOY 260, the stability stratification was unstable, which resulted from the foreign vapor concentration. The increased vapor concentration led to a 80.83% difference between delta(s)(L,b) and delta(L,b). The correlation coefficients between delta(s)(L,b) and delta(L,b) decreased from 0.96 to 0.43 when dataset on DOY 260 was included, indicating foreign vapor increased the uncertainty in the estimation of delta O-18 of ET (delta(ET)) and delta O-18 of transpiration (delta(T)) in the forest ecosystem. Path analysis results suggested that water vapor concentration was the major factor influencing the partitioning of ET with isotopic approach in the forest ecosystem. Since the increased water vapor concentration and decreased atmosphere delta O-18 disturbed the estimation of delta(E), delta(T), delta(ET), the isotopic approach cannot be used in partitioning ET under this condition on DOY 260. Therefore, under most circumstances the isotopic approach can be used to partition ET for forest ecosystem in a non-steady state (NSS), while water vapor concentration may cause uncertainties. (C) 2013 Elsevier B.V. All rights reserved.