兴都库什喜马拉雅地区高海拔树木生长对气候变化的响应
High-altitude tree growth responses to climate change across the Hindu Kush Himalaya
Lili Zheng 1Narayan Prasad Gaire 2Peili Shi1
作者信息
- 1. Lhasa Plateau Ecosystem Research Station,Key Laboratory of Ecosystem Network Observation and Modeling,Institute of Geographic Sciences and Natural Resources Research,Chinese Academy of Sciences,Beijing 100101,China;College of Resources and Environment,University of Chinese Academy of Sciences,Beijing 100190,China
- 2. CAS Key Laboratory of Tropical Forest Ecology,Xishuangbanna Tropical Botanical Garden,Chinese Academy of Sciences,Menglun,Mengla,Yunnan 666303,China;Central Department of Environmental Science,Tribhuvan University,Kirtipur,Kathmandu,Nepal
- 折叠
摘要
高海拔地区快速升温可能导致树木对温度响应更为敏感,而限制高海拔地区树木生长的关键气候因子以及气候变化对树木生长产生多大程度的影响尚不清楚.本研究在兴都库什喜马拉雅地区收集了73个样点的树轮数据,包括3个优势属的树种(Abies属、Juniperus属和Picea属),样点海拔均在3000m以上.将时间动态规整(dynamic time warping)的方法用于建立亚区域年表,以考虑不同站点年表之间变化的同步性.同时,定量分析了气候因子对树木生长的贡献以及树木生长与气候因子关系的时空动态.研究结果发现,73个站点年表可以聚为3类,且与其所处的生物气候区相对应,即西喜马拉雅地区,中东喜马拉雅地区和藏东南地区.在干旱的西喜马拉雅地区,树木生长与冬、春两季的降水呈正相关关系,而在湿润的藏东南地区,树木生长与冬季温度和春季降水呈正相关关系.树木生长受最低温度的影响最大,特别是冬季温度,其重要性从西到东呈现递增趋势.滑动窗口相关分析表明,在中西喜马拉雅地区,影响树木生长的冬季温度信号在减弱,然而在藏东南地区该信号随着1980年以来的快速升温而增强.本研究结果表明,若该地区升温持续,在西喜马拉雅地区可能会因变暖引起的水分亏缺而造成森林衰退,而在藏东南地区因树木生长得益于变暖而使得森林扩张.
Abstract
Aims Rapid warming at high altitudes may lead to a higher sensitivity in tree growth to temperature.The key factors constraining tree radial growth and to what extent regional tree growth has suffered from climatic changes are unclear.Methods Tree-ring width data were collected from 73 sites across the Hindu Kush Himalaya(HKH),including three dominant genera(Abies,Juniperus and Picea)at high altitudes over 3000 m.Dynamic time warping was introduced to develop subregional chronologies by considering the synchrony of annual tree growth among different sites.We quantified the contribution of the climate variables,and analyzed the spatiotemporal variation of the growth-climate relationship.Important Findings The site chronologies were grouped into three clusters,corresponding to the three distinct bioclimatic zones,i.e.the western HKH,central-eastern HKH and southeastern Tibetan Plateau(TP).Tree growth was positively correlated to winter and spring precipitation in the drier western HKH,and to winter temperature and spring precipitation in the humid southeastern TP.Tree growth was markedly constrained by the minimum temperature,especially in winter,with its importance increasing from the west toward the east.As shown by moving correlation analysis,the signal of winter temperature in tree growth was weakened in the western and central-eastern HKH,while it was enhanced in the southeastern TP following rapid warming since the 1980s.Our results highlight that continuous warming may cause forest recession due to warming-induced moisture deficit in the western HKH,but forest expansion in the southeastern TP.
关键词
树轮/高海拔森林/关键气候因子/树木生长-气候的关系/生长趋势/气候敏感性Key words
tree ring/high-altitude forests/key climate factors/tree growth-climate relationships/growth trends/climate sensitivity引用本文复制引用
基金项目
National Natural Science Foundation of China and ICIMOD Joint Research Project(41661144045)
出版年
2021
NETL
NSTL
维普
万方数据