文献类型：期刊文献

英文题名：Stable isotopes reveal differences in climate sensitivity and physiological responses between dieback and healthy trees in a shelter forest

作者：Sun, ShouJia[1,2,3] Zhang, Jinsong[1,2,3] Yin, Changjun[1,2,3] Guan, Chongfan[1,2,3] Zhang, Lanxiao[1,2,3] Meng, Ping[1,2,3]

第一作者：孙守家;Sun, ShouJia

通信作者：Yin, CJ[1]

机构：[1]Chinese Acad Forestry, Res Inst Forestry, Key Lab Tree Breeding & Cultivat State Forestry A, Beijing 100091, Peoples R China;[2]Nanjing Forestry Univ, Collaborat Innovat Ctr Sustainable Forestry South, Nanjing 210037, Peoples R China;[3]Henan Xiaolangdi Earth Crit Zone Natl Res Stn Mid, Jiyuan 454650, Peoples R China

年份：2022

卷号：325

外文期刊名：AGRICULTURAL AND FOREST METEOROLOGY

收录：;Scopus(收录号：2-s2.0-85137284856);WOS:【SCI-EXPANDED(收录号:WOS:000911777300001)】；

基金：This work was supported by the National Natural Science Foundation of China (grant number: 32171871), the National Key Research and Development Project (grant no. 2020YFA0608101), the 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：Forest decline; Tree-ring width; Intrinsic water-use efficiency; Climate response; Physiological regulations

摘要：Tree-ring stable isotopes provide insights into the drought-induced eco-physiological mechanisms of forests. We investigated the growth of poplar and Mongolian pine trees decline in the Three-North Shelter Forest, and analyzed the differences in tree-ring width (TW), delta C-13, delta O-18, and intrinsic water-use efficiency (iWUE) between dieback and healthy trees. An R package was used to quantify the relative contributions of climatic and physi-ological factors to growth. Both TW and basal area increment were lower for the dieback poplar and Mongolian pine than for the healthy trees.delta C-13, delta O-18, and iWUE were higher for the dieback poplar than for the healthy individuals; there were no significant differences in Mongolian pine. The measured iWUE for healthy poplar, healthy and dieback Mongolian pine were consistent with the modeled iWUE for C-i/C-a scenario, indicating the stomata were open and C-i increased along with C-a. In contrast, the measured iWUE was higher for the dieback poplar than for the healthy individuals, which was consistent with the constant C-i scenario and partial stomatal closure. A significant decreasing C-i/C-a was detected only for the dieback poplar, reflecting the diversity in the leaf gas-exchange strategies of the two species. Pearson coefficients showed that on the annual timescale, tree growth was significantly negatively correlated with temperature, VPD, and iWUE, but positively correlated with SPEI. Moreover, the relationships between TW and stable isotopes and stomatal regulation, which differed in the two species, were affected by the dieback process. Furthermore, iWUE and delta O-18 had the highest and lowest relative contributions to TW, respectively. The relative contribution of meteorological factors (Tem, VPD and SPEI) to the growth was significantly lower than that of physiological factors (iWUE and delta O-18). Compared with the healthy controls of both species, the dieback trees were less sensitive to climate conditions, but the effects of physiological activities on growth were greater. These results provide a better understanding of the climate sensitivity and physiological responses of trees under long-term drought conditions.