文献类型：期刊文献

英文题名：Effects of thinning and understory removal on water use efficiency of Pinus massoniana: evidence from photosynthetic capacity and stable carbon isotope analyses

作者：Wang, Ting[1,2] Xu, Qing[1] Zhang, Beibei[1] Gao, Deqiang[1] Zhang, Ying[1] Jiang, Jing[3] Zuo, Haijun[1]

第一作者：Wang, Ting

机构：[1] Key Laboratory of Forest Ecology and Environment of National Forestry and Grassland Administration, Ecology and Nature Conservation Institute, Chinese Academy of Forestry, Beijing, 100091, China; [2] College of Agronomy and Agricultural Engineering, Liaocheng University, Liaocheng, 252000, China; [3] Department of Forest and Conservation Sciences, Faculty of Forestry, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada

年份：2024

卷号：35

期号：1

外文期刊名：Journal of Forestry Research

收录：EI(收录号：20240615531855);Scopus(收录号：2-s2.0-85184281883)

语种：英文

外文关键词：Carbon - Climate change - Efficiency - Forestry - Isotopes - Physiological models - Physiology - Regression analysis - Soil moisture - Water supply

摘要：Understanding the relationship between forest management and water use efficiency (WUE) is important for evaluating forest adaptability to climate change. However, the effects of thinning and understory removal on WUE and its key controlling processes are not well understood, which limits our comprehension of the physiological mechanisms of various management practices. In this study, four forest management measures (no thinning: NT; understory removal: UR; light thinning: LT; and heavy thinning: HT) were carried out in Pinus massoniana plantations in a subtropical region of China. Photosynthetic capacity and needle stable carbon isotope composition (δ13C) were measured to assess instantaneous water use efficiency (WUEinst) and long-term water use efficiency (WUEi). Multiple regression models and structural equation modelling (SEM) identified the effects of soil properties and physiological performances on WUEinst and WUEi. The results show that WUEinst values among the four treatments were insignificant. However, compared with the NT stand (35.8?μmol·mol?1), WUEi values significantly increased to 41.7?μmol·mol?1 in the UR, 50.1?μmol·mol?1 in the LT and 46.6?μmol·mol?1 in HT treatments, largely explained by photosynthetic capacity and soil water content. Understory removal did not change physiological performance (needle water potential and photosynthetic capacity). Thinning increased the net photosynthetic rate (An) but not stomatal conductance (gs) or predawn needle water potential (ψpd), implying that the improvement in water use efficiency for thinned stands was largely driven by radiation interception than by soil water availability. In general, thinning may be an appropriate management measure to promote P. massoniana WUE to cope with seasonal droughts under future extreme climates. ? Northeast Forestry University 2024.