Summary Wood anatomy plays a key role in plants' ability to persist under drought and should therefore predict demography. Plants balance their resource allocation among wood cell types responsible for different functions. However, it remains unclear how these anatomical trade‐offs vary with water availability, and the extent to which they influence demographic rates. We investigated how wood anatomical trade‐offs were related to drought and demographic rates, for seedling communities in four tropical dry forests differing in their aridity indexes (AIs). We measured wood density, as well as vessel, fiber and parenchyma traits of 65 species, and we monitored growth and survival for a 1‐yr period. Two axes defined wood anatomical structure: a fiber‐parenchyma axis and a vessel‐wood density axis. Seedlings in drier sites had larger fiber but lower parenchyma fractions, while in less dry forests, seedlings had the opposite allocation pattern. The fiber–parenchyma trade‐off was unrelated to growth but was positively related to survival, and this later relationship was mediated by the AI. These findings expand our knowledge about the wood anatomical trade‐offs that mediate responses to drought conditions and influence demographic rates, in the seedling layer. This information is needed to anticipate future responses of forests to changing drought conditions.

中文翻译：

---

将幼木解剖学权衡与干旱和热带干旱森林幼苗的生长和生存联系起来


摘要 木材解剖学在植物在干旱下持续存在的能力中起着关键作用，因此应该预测人口学。植物在负责不同功能的木细胞类型之间平衡其资源分配。然而，目前尚不清楚这些解剖学权衡如何随水资源供应而变化，以及它们影响人口比率的程度。我们调查了四个热带干旱森林中干旱指数 （AI） 不同的幼苗群落的木材解剖学权衡与干旱和人口比率的关系。我们测量了木材密度，以及 65 个物种的血管、纤维和薄壁组织特征，并监测了 1 年的生长和存活率。两个轴定义了木材解剖结构：纤维-薄壁组织轴和血管-木材密度轴。在较干燥的地方，幼苗具有较大的纤维但较低的薄壁组织分数，而在不太干燥的森林中，幼苗具有相反的分配模式。纤维-薄壁组织权衡与生长无关，但与生存呈正相关，这种后来的关系是由 AI 介导的。这些发现扩展了我们对木材解剖学权衡的了解，这些权衡在幼苗层中介导对干旱条件的反应并影响人口增长率。需要这些信息来预测森林未来对不断变化的干旱条件的反应。