A recent growth increase of European beech (Fagus sylvatica L.) at its Mediterranean distribution limit contradicts drought stress
A recent growth increase of European beech (Fagus sylvatica L.) at its Mediterranean distribution limit contradicts drought stress
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DOI：
10.1007/s10342-013-0737-7
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发表时间：
2013
影响因子：
2.8
通讯作者：
Willy Tegel;A. Seim;Dietrich Hakelberg;S. Hoffmann;Metodi Panev;Thorsten Westphal;U. Büntgen
中科院分区：
文献类型：
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作者：
Willy Tegel;A. Seim;Dietrich Hakelberg;S. Hoffmann;Metodi Panev;Thorsten Westphal;U. Büntgen
树木生长的未来变化，与温暖和干燥的气候，预计在欧洲地中海盆地的许多物种和地点。然而，对森林生态系统功能和生产力的相关后果的强度和严重性进行量化仍然具有挑战性。对环境气候的微小变化特别敏感的物种特定分布限度可能提供一个理想的试验台，以评估过去生长趋势和极端情况的性质及其负责任的控制。在这里，我们试图了解如何二十世纪气候变化影响欧洲山毛榉（Fagus sylvaticaL.）的增长。分布于巴尔干半岛的半岛的阿尔巴尼亚和马其顿。我们从海拔约1,450米的未受干扰的混交林中采集了93棵活树。还有29块来自附近历史建筑的木材应用不同的树木年轮去趋势技术，可以将具有不同程度的高频到低频变化的复合年表发展到公元1648年。与当地气象站测量值和大陆格箱气候指数的比较揭示了生长-气候响应模式的时空不稳定性。然而，在1951-1995年期间，径向山毛榉生长的年与年和十年波动与6月至9月的温度呈显著负相关（P< 0.001）。增加山毛榉生长和夏季温度下降之间的这种（逆）关系是植物可用的土壤水分，这可能控制环宽度形成的物种特定的东南分布限制附近的重要性有所指示。山毛榉生长和干旱（scPDSI;r= 0.57）之间的显着正相关性确认代谢干旱的限制。然而，一个意想不到的世纪后期的增长不仅矛盾以前观察到的增长依赖夏季土壤水分，但也否认任何假定的干旱引起的森林生态系统抑制在地中海盆地的这一部分。
Future changes in tree growth, associated with a warmer and drier climate, are predicted for many species and locations across the European Mediterranean Basin. However, quantification of the intensity and severity of related consequences for forest ecosystem functioning and productivity remains challenging. Species-specific distribution limits that are particularly sensitive to small changes in the ambient climate may provide an ideal test bed to assess the nature of past growth trends and extremes and their responsible controls. Here, we seek to understand how twentieth century climate change affected the growth of European beech (Fagus sylvaticaL.) nearby its south-eastern distribution limit in Albania and Macedonia on the Balkan Peninsula. We sampled 93 living trees from undisturbed mixed forest stands at ~1,450 m a.s.l. and 29 timbers from nearby historical buildings. Application of different tree-ring detrending techniques allowed robust composite chronologies with varying degrees of high- to low-frequency variability to be developed back to 1648ad. Comparison with local meteorological station measurements and continental grid-box climate indices revealed spatiotemporal instability in growth–climate response patterns. Nevertheless, year-to-year and decadal-long fluctuations in radial beech growth were significantly (P< 0.001) negatively correlated at −0.61 with June–September temperature over the 1951–1995 period. This (inverse) relationship between increased beech growth and decreased summer temperature is somewhat indicative for the importance of plant-available soil moisture, which likely controls ring width formation near the species-specific south-eastern distribution limit. Significant positive correlations between beech growth and drought (scPDSI;r= 0.57) confirm metabolistic drought constraints. However, an unexpected late twentieth century growth increase not only contradicts the previously observed growth dependency to summer soil moisture, but also denies any putative drought-induced forest ecosystem suppression in this part of the Mediterranean Basin.