Tree growth-climate relationships of Juniperus tibetica along an altitudinal gradient on the southern Tibetan Plateau
Tree growth-climate relationships of Juniperus tibetica along an altitudinal gradient on the southern Tibetan Plateau
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DOI：
10.1007/s00468-012-0813-5
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发表时间：
2013-04-01
影响因子：
2.3
通讯作者：
Braeuning, Achim
中科院分区：
文献类型：
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作者：
He, Minhui;Yang, Bao;Braeuning, Achim
青藏高原南部形成了林区和高山草原之间的交错带，因此，在这个半湿润的地区，树木的生长预计对气候变化反应敏感。我们从两个研究点的169棵树上采集了328个增量芯，沿海拔4,000到4,500米的横断面分布。目的：评价马尾松树木生长与气候的海拔相关性。平均系列间相关系数(RBAR)、表达的种群信号和信噪比等标准树种年代学统计参数与海拔高度的相关性不显著。树轮序列的平均节段长度和平均生长速率随海拔升高而增大。与已有气候资料的相关分析和响应函数分析表明，海拔高度对树木生长-气候关系没有显著影响。相反，当地树木的生长主要是由共同的区域气候信号驱动的，这也通过公元1550-2010年共同周期内所有年表之间的显著相关性来表明。4-6月的水分变化对树木生长的影响最大，甚至接近树木的上限。
The southern Tibetan Plateau forms the ecotone between forest areas and alpine steppes and thus, tree growth is expect to react sensitive to climate variability in this semi-humid region. We sampled 328 increment cores from 169 trees at two study sites at four elevations along altitudinal transects from 4,000 to 4,500 m a.s.l. to evaluate elevation-dependent tree growth-climate relationships of Juniperus tibetica. Standard dendrochronological statistical parameters like mean inter-series correlation (Rbar), expressed population signal as well as signal-to-noise ratio is not significantly correlated to elevation. Mean segment lengths and average growth rates of the tree-ring series increase with elevation. Correlation and response function analysis with available climate data indicate that elevation has no significant effect on tree growth-climate relationships. Instead, local tree growth is mainly driven by common regional climatic signals as it is also indicated by significant correlations between all chronologies over their common period of A.D. 1550-2010. Moisture variability during April-June has the highest impact on tree growth, even close to the upper tree limit.