Tree ring isotopic composition, radial increment and height growth reveal provenance-specific reactions of Douglas-fir towards environmental parameters
Tree ring isotopic composition, radial increment and height growth reveal provenance-specific reactions of Douglas-fir towards environmental parameters
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DOI：
10.1007/s00468-012-0765-9
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发表时间：
2013-02-01
影响因子：
2.3
通讯作者：
Gessler, Arthur
中科院分区：
文献类型：
--
作者：
Jansen, Kirstin;Sohrt, Jakob;Gessler, Arthur
在寻找能够忍受夏季干旱的木材品种时，预计夏季干旱在未来会更加频繁，道格拉斯冷杉经常被讨论为中欧云杉的潜在替代品。为了评估道格拉斯冷杉种源对气候和天气相关环境条件的生理和生长反应，我们在德国西南部沿海拔梯度的三个地点进行了种源试验。研究了北美6种不同种源道格拉斯杉木年轮中氧（δ O-18）和碳（δ C-13）稳定同位素组成，以及7年的径向增量和长期高度增长。结果表明：2003年极端干热年，不同种源道格拉斯冷杉在山谷最干燥和最温暖地点的干旱敏感性存在明显差异。树木年轮δ O-18和δ C-13的关系表明，Pamelia Creek、Cameron Lake、Duncan Paldi和Conrad Creek种源的生长下降明显归因于气孔导度的降低。这些响应与种源原产地的长期平均气候无关，长期（高度）生长潜力最低的种源受2003年极端干旱的径向增量影响最小。因此，在选择适合未来气候条件的道格拉斯冷杉种源时，我们可能需要考虑到对极端干旱时期的适应和长期生长性能之间的权衡。因此，需要对极端干旱事件发生的具体地点进行评估，以选择适当的来源。
In the search of timber species being tolerant towards summer droughts, which are expected to be more frequent in future, Douglas-fir is often discussed as a potential alternative for spruce in Central Europe. To assess physiological and growth reactions of Douglas-fir provenances towards climate- and weather-related environmental conditions we took advantage of a provenance trial with three sites in south-western Germany located along an elevation gradient. We examined six different provenances of Douglas-fir from North America for oxygen (delta O-18) and carbon (delta C-13) stable isotope composition in tree rings as well as for radial increment for a 7 year period and long-term height growth. Our results show that different Douglas-fir provenances clearly vary in their drought sensitivity at the driest and warmest site in the valley as shown by the radial growth decline in the extreme dry and hot year 2003. The growth decline in the provenances Pamelia Creek, Cameron Lake, Duncan Paldi and Conrad Creek could be clearly attributed to a reduction in stomatal conductance as assessed by the relations between delta O-18 and delta C-13 in the tree rings. These responses were not related to the long-term average climate at the places of origin of the provenances and the provenances with the lowest long-term (height) growth potential were the ones least affected in radial increment by the extreme drought of 2003. When selecting suitable Douglas-fir provenances, which are adapted to the climatic conditions projected for the future we thus might need to take into account the trade-off between the adaptation to extreme drought periods and the long-term growth performance. Site-specific evaluations of the probability of extreme drought events are thus needed to select the appropriate provenances.