西藏米林高山松径向生长对气候变化的响应  

Response of radial growth of Pinus densata forest to climate change in Milin City of Xizang,China

作　　者：刘宇[1] 王亚锋 刘波[2] 梁尔源[3] LIU Yu;WANG Yafeng;LIU Bo;LIANG Eryuan(College of Ecology and Environment,Nanjing Forestry University,Nanjing 210037,Jiangsu;College of Urban and Environment Sciences,Northwest University,Xi'an 710127,Shaanxi;State Key Laboratory of Tibetan Plateau Earth System,Environment and Resources(TPESER),Institute of Tibetan Plateau Research,Chinese Academy of Sciences,Beijing 100101)

机构地区：[1]南京林业大学生态与环境学院,江苏南京210037 [2]西北大学城市与环境学院,陕西西安710127 [3]中国科学院青藏高原研究所,青藏高原地球系统与资源环境全国重点实验室,北京100101

出　　处：《第四纪研究》2024年第4期928-938,共11页Quaternary Sciences

基　　金：科技部第二次青藏高原综合科学考察研究项目(批准号:2019QZKK0301);南京林业大学南方现代林业协同创新中心资助项目共同资助。

摘　　要：西藏东南部米林市广泛分布着高山松针叶林,很少受到人为活动的干扰,具有开展树木年代学研究的潜力。为此,本研究以藏东南米林市的高山松(Pinus densata)为研究对象,拟建立高山松树轮宽度标准年表,探讨高山松林的径向生长对气候变化的响应。相关分析和偏相关分析的结果表明,高山松的径向生长与上一年11月最低气温、当年8月最低气温和平均气温、当年4月降水和帕默尔干旱指数均呈显著正相关,与当年6月降水呈显著负相关。其中,高山松径向生长与4月降水量的相关最为显著,表明生长季初期降水量的缺乏限制了高山松的径向生长。百年尺度上高山松年表缺失轮数量有明显的上升趋势,并且缺轮数量与上一年9月至当年4月期间的逐月帕默尔干旱指数均呈显著正相关关系,表明生长季初期和末期的干旱不利于树木的生长。滑动相关分析进一步表明4月降水对高山松生长的主导作用。近一百年来米林市气候暖干化趋势显著,且季节降水分配不均,由此导致了高山松径向生长的水分限制。未来持续的气候变暖可能威胁米林市高山松林的正常生长。上述结论为快速气候变化背景下的西藏针叶林管理与保护提供了参考依据。Pinus densata coniferous forest is widely distributed in Milin City of southeast Xizang of China and is little disturbed by human activities,showing the high dendrochronological potential.Herein,Pinus densata forest in Milin City of southeast Xizang(29°14′N,94°13′E,2950 m a.s.l.)is selected as the research object.We aim to establish the standard tree-ring-width chronology and explore its responses to climate change.Based on the ring-width data from 53 tree individuals,we constructed a highly replicated tree-ring width chronology with a length of 313 years(1709~2021).The representative interval for this chronology changes from 1935 to 2021(EPS>0.85),the correlation between cores is 0.353,and the mean sensitivity is 0.32.Five climatic variables(monthly average temperature,monthly maximum temperature,monthly minimum temperature,monthly precipitation,and monthly Palmer Drought Severity Index(PDSI))between 1901 and 2021 used in this study were extracted from the CRU TS 4.1 dataset(spatial resolution:0.5°×0.5°).Results of correlation analysis and partial correlation analysis showed that the radial growth of Pinus densata was significantly positively correlated with average minimum temperature in November of the previous year and average minimum temperature and average temperature in current August,but it was significantly negatively correlated with the precipitation in current June.Among different climatic variables,the highest correlation was found between tree growth and precipitation of current April,suggesting that a lack of precipitation in the early growing season limited its radial growth.Changes in the number of missing rings in Pinus densata over the last century showed a significant upward trend,and it was significantly positively correlated with the monthly PDSI from previous September to current April,indicating that drought stress at the beginning and end of the growing season was unfavorable for tree growth.Moving correlation analysis further revealed that April precipitation played a dominant ro

关 键 词：树木年轮 气候变化 暖干气候 高山松 缺失轮 

分 类 号：S718.5[农业科学—林学] P467[天文地球—大气科学及气象学]