Miranda Jose Carlos, Calderaro Chiara, Cocozza Claudia, Lasserre Bruno, Tognetti Roberto, von Arx Georg
Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf, Switzerland.
Dipartimento di Bioscienze e Territorio, Università degli Studi del Molise, Pesche, Italy.
Front Plant Sci. 2022 Mar 23;13:855741. doi: 10.3389/fpls.2022.855741. eCollection 2022.
European beech ( L.) is a widespread and economically important temperate tree species in Europe. The warmer temperatures and severe drought events expected in the future, especially in Mediterranean areas, could affect the vitality and productivity of beech stands that have been intensively used in these areas in the past. Here, we aim to assess the wood anatomical responses of beech to environmental variability and silvicultural practices by investigating three beech stands along an elevational gradient (1,200 to 1,950 m a.s.l.) in the Apennines (Italy). Therefore, we quantified several anatomical traits of the xylem vessels related to tree hydraulics from five trees per stand and investigated variability between and within tree rings. Our results suggest generally limited trait plasticity, with higher plasticity of mean vessel lumen area and theoretical hydraulic conductivity, while maximum vessel size and mean hydraulic diameter were less plastic, likely because of the stronger determination by tree height. High-elevation trees were hydraulically more limited than trees at a mid and lower elevation as indicated by the more conservative anatomical configuration, i.e., comparatively smaller vessels and a 50% tighter trait coordination. Cessation of coppicing resulted in a hydraulically safer anatomy with comparatively smaller vessels at the most intensively used site (1,200 m), triggered by increased water demand due to an increase in canopy density, and thus, an increase in stand transpiration. Furthermore, maximum vessel size at the beginning showed different climate sensitivity compared to the rest of the tree ring, while intra-ring anatomical profiles showed little difference between normal and the 5 years with the highest and lowest mean temperature and precipitation. Overall, this study highlights the challenges to separate the externally induced medium- to longer-term responses from ontogenetically determined patterns. We, therefore, call for more comprehensive studies to further explore and verify the plasticity of wood anatomical traits in European beech in response to short- to long-term environmental fluctuations to gain a mechanistic understanding useful for sustainable forest ecosystems.
欧洲山毛榉（Fagus sylvatica L.）是欧洲一种分布广泛且具有重要经济价值的温带树种。预计未来气温升高和严重干旱事件，尤其是在地中海地区，可能会影响过去在这些地区被密集利用的山毛榉林分的活力和生产力。在此，我们旨在通过调查意大利亚平宁山脉沿海拔梯度（海拔1200至1950米）的三个山毛榉林分，评估山毛榉对环境变化和造林实践的木材解剖学响应。因此，我们对每个林分的五棵树的与树木水力相关的木质部导管的几个解剖学特征进行了量化，并研究了年轮之间和年轮内部的变异性。我们的结果表明，一般性状可塑性有限，平均导管腔面积和理论水力传导率的可塑性较高，而最大导管尺寸和平均水力直径的可塑性较小，这可能是因为受树高的影响更大。高海拔树木在水力方面比中低海拔树木更受限制，这表现为解剖结构更为保守，即导管相对较小且性状协调性更紧密50%。在使用最密集的地点（海拔1200米），由于冠层密度增加导致水分需求增加，从而林分蒸腾作用增加，停止平茬导致了水力上更安全的解剖结构，导管相对较小。此外，开始处的最大导管尺寸与年轮其余部分相比显示出不同的气候敏感性，而年轮内解剖学剖面在正常年份与平均温度和降水量最高及最低的5年之间几乎没有差异。总体而言，本研究强调了区分外部诱导的中长期响应与个体发育决定模式的挑战。因此，我们呼吁进行更全面的研究，以进一步探索和验证欧洲山毛榉木材解剖学特征对短期至长期环境波动的可塑性，从而获得有助于可持续森林生态系统的机制性理解。
