NOAA/WDS Paleoclimatology - Büntgen - DolinaWaksmunska - PCAB - ITRDB POLA028

We analyzed growth responses to climate of 24 tree-ring width and four maximum latewood density chronologies from the greater Tatra region in Poland and Slovakia. This network comprises 1183 ring-width and 153 density measurement series from four conifer species (Picea abies (L.) Karst., Larix decidua Mill., Abies alba (L.) Karst., and Pinus mugo (L.)) between 800 and 1550 m a.s.l. Individual spline detrending was used to retain annual to multi-decadal scale climate information in the data. Twentieth century temperature and precipitation data from 16 grid-boxes covering the 48-50 °N and 19-21 °E region were used for comparison. The network was analyzed to assess growth responses to climate as a function of species, elevation, parameter, frequency and site ecology. Twenty ring-width chronologies significantly correlated (P < 0.05) with June-July temperatures, whereas the latewood density chronologies were correlated with the April-September temperatures. Climatic effects of the previous-year summer generally did not significantly influence ring formation, whereas site elevation and frequency of growth variations (i.e., inter-annual and decadal) were significant variables in explaining growth response to climate. Response to precipitation increased with decreasing elevation. Correlations between summer temperatures and annual growth rates were lower for Larix decidua than for Picea abies. Principal component analysis identified five dominant eigenvectors that express somewhat contrasting climatic signals. The first principal component contained highest loadings from 11 Picea abies ring-width chronologies and one Pinus mugo ring-width chronology and explained 42% of the network's variance. The mean of these 12 high-elevation chronologies was significantly correlated at 0.62 with June-July temperatures, whereas the mean of three latewood density chronologies, which loaded most strongly on the fourth principal component, significantly correlated at 0.69 with April-September temperatures (P < 0.001 over the 1901-2002 period in both cases). These groupings allow for a robust estimation of June-July (1661-2004) and April-September (1709-2004) temperatures, respectively. Comparison with reconstructions from the Alps and Central Europe supports the general rule of the dominant influence of growing season temperature on high-elevation forest growth.

我们针对波兰与斯洛伐克大塔特拉地区的24条树轮宽度年表（tree-ring width chronologies）与4条最大晚材密度年表（maximum latewood density chronologies），开展了树木生长对气候响应的相关分析。该数据集网络涵盖源自4种针叶树种（conifer species）的1183条轮宽测量序列与153条密度测量序列，采样海拔介于800至1550米a.s.l.。研究采用单样条去趋势法（spline detrending），以保留数据中涵盖年际至多年代际尺度的气候信号信息。本研究使用覆盖48°N–50°N、19°E–21°E区域的16个网格单元（grid-boxes）的20世纪气温与降水数据作为对照数据集。针对该数据集网络开展分析，以探究树木生长对气候的响应如何随树种、海拔、参数、频率及样地生态特征发生变化。20条树轮宽度年表与6-7月气温呈显著相关（P < 0.05），而晚材密度年表则与4-9月气温存在相关性。前一年夏季的气候效应通常不会对年轮形成产生显著影响，而样地海拔与生长变异频率（即年际与年代际尺度）是解释树木生长对气候响应的关键变量。树木生长对降水的响应随海拔降低而增强。欧洲落叶松（Larix decidua Mill.）的夏季气温与年生长速率的相关性低于欧洲云杉（Picea abies (L.) Karst.）。主成分分析（principal component analysis）识别出5个主导特征向量（eigenvectors），它们呈现出存在一定差异的气候信号。第一主成分的载荷量（loadings）主要来自11条欧洲云杉树轮宽度年表与1条黑松（Pinus mugo (L.)）树轮宽度年表，可解释该数据集网络42%的方差。这12条高海拔年表的平均值与6-7月气温的相关系数达0.62，呈显著相关；而3条晚材密度年表的载荷量主要集中于第四主成分，其平均值与4-9月气温的相关系数达0.69，同样呈显著相关（两个序列在1901–2002年时段内均满足P < 0.001）。通过上述分组，可分别可靠重建1661–2004年的6-7月气温与1709–2004年的4-9月气温。与阿尔卑斯山区及中欧地区的古气候重建结果对比后，本研究结果印证了“生长季气温对高海拔森林生长具有主导影响”这一通用规律。