文献类型：期刊文献

英文题名：Stable isotope analysis reveals prolonged drought stress in poplar plantation mortality of the Three-North Shelter Forest in Northern China

作者：Sun, ShouJia[1,2] He, Chunxia[1,2] Qiu, Lanfen[3] Li, Chunyou[4] Zhang, JinSong[1,2] Meng, Ping[1,2]

第一作者：孙守家;Sun, ShouJia

通信作者：Meng, P[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, Jiangsu, Peoples R China;[3]Beijing Inst Landscape Architecture, Beijing Key Lab Ecol Funct Assessment & Regulat T, Beijing 100102, Peoples R China;[4]Agr Univ Hebei, Coll Landscape & Travel, Baoding 071000, Peoples R China

年份：2018

卷号：252

起止页码：39-48

外文期刊名：AGRICULTURAL AND FOREST METEOROLOGY

收录：;Scopus(收录号：2-s2.0-85040366829);WOS:【SCI-EXPANDED(收录号:WOS:000427341400005)】；

基金：This work was supported financially by the Special Fund for Forest Scientific Research in the Public Welfare (Grant No. 201404206). We thank China Meteorological Data Service Center for meteorological data. Finally, we acknowledge Xianchong Wan and Hongyan Sun for reviewing and revising the manuscript, and the two anonymous reviewers who helped to improve the manuscript with insightful comments.

语种：英文

外文关键词：Populus simonii Can; Tree rings; Carbon isotope; Intrinsic water-use efficiency; Land use; Prolonged drought stress

摘要：The Three-North Shelter Forest (TNSF) is an important ecological barrier in northern China. However, in the last decade, poplar tree degradation has occurred in similar to 80% of TNSF stands in Zhangbei County (Hebei Province), with about one-third of trees either dead or dying. Using isotopic techniques, we investigated the corrected delta C-13 value of tree-ring (delta C-13(cor)) and intrinsic water-use efficiency (iWUE) differences between non-dieback and dieback trees of the same age to understand the cause of poplar dieback death associated with the TNSF. We found that the diameter of poplar trees within the same age group decreased as degradation progressed. From 1997, inter-group differences of delta C-13(cor) and iWUE occurred but were not statistically significant. The differences became significant from 2002. Comparisons suggest that the continuous occurrence of positive Delta iWIJE (iWUE(dieback)-iWUE(non-dieback)) may be the threshold for subsequent divergence of the two groups. Stepwise regression revealed that the impact of groundwater depth on iWUE was stronger than that of other environmental factors (e.g., temperature and evapotranspiration) and was the leading cause of poplar degradation. IsoSource model analyses indicated that non-dieback trees took water mainly from soil 30-80 cm below the ground surface, and that dieback trees did it mainly from 0-30 cm below the surface. Non-dieback trees used more water from the 80-150 cm soil layer and groundwater than did dieback trees. Groundwater depth, which increased in the experimental area and so aggravated local droughts, was strongly related to cumulative water consumption but not to evapotranspiration (ET0), indicating that increasing groundwater depth was primarily caused by the change in land use. Therefore, poplar dieback in the TNSF in Zhangbei County was attributed to groundwater overuse associated with changed land use, which enhanced the duration and intensity of water stress on the trees.