• Wood carbon (C) concentration is a key wood trait that varies widely among tree species, but our understanding of the factors governing this trait is limited, despite reason to hypothesize that wood C varies systematically across environmental gradients.
• We compiled a novel database of 1145 geo-referenced wood C observations from 415 species, to elucidate climate correlates of wood C concentrations, and test if these relationships differ across tissue types and major taxonomic divisions (i.e. angiosperms vs gymnosperms).
• Climate variables, including mean annual temperature (MAT) and precipitation and temperature seasonality, are significantly correlated with wood C concentrations. Relationships between wood C and these variables differ across tissue types and taxonomic divisions, yet there is a negative relationship between wood C and MAT that exists across all tissues and species groups.
• Wood C concentrations in trees are influenced by climate, with experimental evidence (albeit scant) indicating that climate-driven changes in lignin concentrations likely govern these relationships. Our study presents among the first lines of evidence indicating that wood C concentrations are correlated with environmental conditions, thereby enhancing our understanding of the potential adaptive significance of wood C variation in trees.

中文翻译：

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跨越气候梯度的世界树木中的碳浓度

• 木材碳 (C) 浓度是一个关键的木材特性，在不同树种之间差异很大，但我们对控制该特性的因素的理解是有限的，尽管有理由假设木材 C 在环境梯度中存在系统性变化。
• 我们编译了一个包含来自 415 个物种的 1145 个地理参考木材 C 观测值的新数据库，以阐明木材 C 浓度的气候相关性，并测试这些关系是否因组织类型和主要分类学部门（即被子植物与裸子植物）而异。
• 气候变量，包括年平均温度 (MAT) 和降水和温度季节性，与木材 C 浓度显着相关。木材 C 与这些变量之间的关系因组织类型和分类部门而异，但木材 C 和 MAT 之间存在负相关关系，存在于所有组织和物种组中。
• 树木中的木材 C 浓度受气候影响，实验证据（尽管很少）表明气候驱动的木质素浓度变化可能支配了这些关系。我们的研究提供了第一条证据，表明木材 C 浓度与环境条件相关，从而增强了我们对树木中木材 C 变化的潜在适应性意义的理解。