Climatic impact on functional wood anatomy, seasonal wood formation, and tree growth along altitudinal gradients on Corsica

气候极端事件对森林生态系统的影响表现为木材解剖结构的变化，它代表了对气候档案木材的长期记忆，影响了树木液压系统的功能。木材的解剖性质在遗传预定义和物种特定的可塑性范围内作出反应，并可以用图像分析方法进行量化。木材解剖异常，如年内密度波动，在地中海区域内频繁发生，并记录了植被期内干旱时期形成层活动和细胞分化的反应。形成层活动和木材组织分化的时间动态受生长限制气候因子的年际变化和反映短期的影响，但根据高树龄也有长期的气候变异性。我们将分析季节气候对形成层活动、生长速度和形成的木材组织的影响，包括科西嘉岛林区内所有气候类型的海拔梯度。这项研究包括两种常绿松树(松树和黑松)，它们的分布模式在研究的海拔梯度内重叠，允许区分物种特定和环境因素对木材形成的影响。项目捆绑包Corsic Archive内的合作将提供沿海拔梯度的气象数据和气候模型，以及高时间分辨率的木材和降水的稳定氧同位素分析，并将允许测量的生长过程和木材结构的运动学和树木生理学解释。这些数据将被整合到树木生长稳定的同位素模型DendroIso中，并应用于过去几个世纪的气候极端事件，以更好地了解科西嘉岛不同气候时期的水文气候变异性及其对树木生态的影响。

The impact of climate extreme events on forest ecosystems is manifested in structural changes of the wood anatomy which represents a long-term memory in the climate archive wood and which influence the functionality of the hydraulic system of trees. Wood anatomical properties react within genetically predefined and species-specific plasticity and can be quantified with image analytical approaches. Wood anatomical anomalies like intra-annual density fluctuations occur in a high frequency within the Mediterranean region and document the response of cambial activity and cell differentiation in dry spells within the vegetation period. The temporal dynamics ofcambial activity and differencing wood tissues is influenced by interannual variations of growth-limiting climate factors and mirrors shortterm, but according to high tree ages also long-term climate variability. We will analyze the impact of seasonal climate on cambial activity, growth rates, and formed wood tissues`anatomy along an elevation gradient that includes all climatic types within forested regions on Corsica. The study includes tow evergreen pine species (Pinus pinaster, Pinus nigra) whose distribution patterns overlap within thestudied elevation gradient, allowing a differentiation between speciesspecific and environmental factors influencing wood formation.Collaborations within the project bundle CorsicArchive will provide meteorological data and climatological models along the elevationgradient as well as stable oxygen isotope analyses of wood and precipitation water with high temporal resolution and will allow aclimatological and tree physiological interpretation of the measured growth processes and wood structures. These data will be integratedin a tree-growth-stable isotope model DendroIso and applied on former climatic extreme events during the past centuries to gain abetter understanding of the hydroclimatic variability during different climate periods on Corsica, and on their effects on tree ecology.