NOAA/WDS Paleoclimatology - Baw Baw Tree ring width, PAGES Australasia 2k Version

We investigate the causes of variability in a tree‐ring chronology comprising data from Eucalyptus pauciflora Sieb. Ex. Spreng. at the alpine treeline on the Kosciuszko Plateau in New South Wales, Australia. Following verification of crossdating in a subset of the available data, we found that ring width correlates significantly with net radiation, precipitation and mean minimum and maximum air temperature during the preceding winter and spring of the growing season. Our results for spring are consistent with the impact of climate on tree growth in alpine woodlands reported in previous studies. Analyses of snow‐depth data revealed negative correlations with ring width throughout winter and spring. Our results indicate that low temperature and high precipitation during winter negatively affect the growth of E. pauciflora by prolonging spring snow cover. Ring width also correlates significantly with an index of soil dryness and flow in rivers with their headwaters in the Kosciuszko plateau. Given the apparent sensitivity of our chronology to climate and snow conditions, our results suggest that tree‐ring chronologies comprising data from E. pauciflora at the alpine treeline have potential for climatological and hydrological reconstruction in southeast Australia.

我们针对澳大利亚新南威尔士州科修斯科高原阿尔卑斯林线处的雪山桉（Eucalyptus pauciflora Sieb. Ex. Spreng.）样本所构建的树轮年表，探究其变异性的成因。在对可用数据子集的交叉定年进行验证后，我们发现，树轮宽度与生长季前冬季及春季的净辐射、降水量、平均最低和最高气温均呈显著相关关系。本次研究关于春季的结果，与既往研究中报道的气候对阿尔卑斯林地树木生长的影响相一致。对积雪深度数据的分析显示，在整个冬季与春季，积雪深度与树轮宽度均呈负相关关系。研究结果表明，冬季的低温与高降水量会通过延长春季积雪覆盖期，对雪山桉的生长产生负面影响。树轮宽度还与土壤干燥度指数，以及河源位于科修斯科高原的河流径流量呈显著相关关系。鉴于本次构建的年表对气候与积雪条件具有显著敏感性，研究结果表明，基于阿尔卑斯林线处雪山桉样本构建的树轮年表，在澳大利亚东南部的气候学与水文学重建领域具备应用潜力。