Tree-ring anatomy to study two thousand years of climate variability and black spruce adaptations

树木年轮常被用来重建过去的气候和分析森林生态系统对干扰和气候变化的响应。然而，与传统的研究方法，我们不利用所有的信息包含在树木年轮，我们的风险，以获得有偏见的解释。同时使用几个树轮性状和年内分辨率分析，即每个年轮一个以上的测量，另一方面，可能会给我们更精确和详尽的信息，气候变率和树木生态生理。对于这项研究计划，我们将测量多个树木年轮解剖特征的样本的战略网络的树木年轮年表跨越过去两千年，并产生了亚化石和生活黑云杉树从魁北克北方森林。解剖特征将以年内分辨率进行分析，包括管胞腔面积、管胞壁厚度和解剖密度等。这些性状具有特定的气候敏感性，并直接关系到水和热的限制，影响树木生长在生长季节。此外，我们将使用我们的解剖数据，以改善在气候变化的背景下，北方树木的木材生物量积累的生理生态学建模。这项研究计划具有创新潜力，因为我们将开发高通量系统，用于解剖测量，目前世界上只有很少的实验室管理。然后，我们将通过使用最有前途的解剖学特征并将其与我们已经测量的树木年轮特征（宽度，密度，纤维素的稳定同位素）相结合，显着改善魁北克北部地区的气候重建。我们的年内解剖特征也将首次允许重建过去的湿度和温度季节性变化，并评估其对北方森林树木功能的影响。最后，我们将使用基于已开发的生态生理模型反演的新技术来验证对树木功能规则的考虑是否会修改用传统方法获得的树木气候重建结果。我们所有的数据都将提供给其他用户，并将为气候重建提供一个新的参考，因为目前，尽管树木解剖学具有公认的潜力，但尚未开发出覆盖过去两千年的解剖特征年表。

Tree-rings are often used to reconstruct past climate and analyze forest ecosystem responses to disturbances and climate change. However, with traditional research methods we do not exploit all the information contained in tree-rings and we risk to obtain biased interpretations. The use of several tree-ring traits simultaneously and of intra-annual resolution analyses, i.e. more than one measurement per each annual growth ring, may on the other hand give us more precise and exhaustive information on climate variability and tree ecophysiology. For this research program, we will measure multiple tree-ring anatomical traits on the samples of a strategic network of tree-ring chronologies spanning the last two millennia and produced with subfossil and living black spruce trees from the Quebec boreal forest. The anatomical traits will be analyzed with intra-annual resolution and will include, for example, the tracheid lumen area, the tracheid wall thickness and the anatomical density. These traits have a specific climatic sensitivity and are directly related to water and thermal constraints that influence tree growth during the growing season. In addition, we will use our anatomical data to improve the ecophysiological modeling of wood biomass accumulation in boreal trees in the context of climate change. This research program has innovative potential because we will develop high throughput systems for anatomical measurements which are currently managed only by very few laboratories in the world. Then, we will significantly improve the climate reconstructions for the Quebec boreal region by using the most promising anatomical traits and by combining them with the tree-ring traits that we have already measured (width, density, stable isotopes of cellulose). Our intra-annual anatomical traits will also allow, for the first time, the reconstruction of past seasonal changes in humidity and temperature and the assessment of their impact on tree functioning in the boreal forest. Finally, we will use new techniques based on the inversion of the developed ecophysiological models to verify if the consideration of tree functional rules modifies the results of dendroclimatic reconstructions obtained with traditional methods. All our data will be made available to other users and will represent a novel reference for climate reconstructions because currently, despite the recognized potential of dendroanatomy, no chronology of anatomical traits covering the last two millennia has yet been developed.