Abstract The relationship between plant functional traits and soil variables is useful for understanding plant community composition and circumscribing plant functional groups to highlight their adaptations to environmental conditions. The principal aim of this study was to explain assembly patterns of coastal vegetation using functional traits along a short edaphic gradient. The work was carried out on the pioneer zone in the coastal lowland vegetation (foredune) in southern Brazil. We selected 40 functional traits related to the morphology and anatomy of leaves, stems and roots for 60 species recorded in 25 vegetation plots positioned along three transects from the shoreline to slacks. In each plot, floristic and soil data were collected, and functional traits measured. We analysed the relationships between species functional traits and soil factors through RLQ and fourth-corner analyses. Salinity and organic matter content were the most significant edaphic factors in the differentiation of foredune vegetation, while the most significant traits to explain plant adaptations to coastal environments were plant height, sclerenchyma, spongy parenchyma and reserves of inulin in the root. Two functional groups of plants were circumscribed: a conservative group formed by trees and shrubs dominated the Woody Community, with low values of SLA (specific leaf area), thick cuticles, high frequencies of phenolic compounds and crystals, woody stems and great plant heights, which tended to invest in permanent aerial organs; and a more heterogeneous group of herbaceous plants (found in Beach Community, Non-floodable, and Wet Communities) with acquisitive characteristics (high SLA values) or conservative strategy (rhizome and xylopodium). Finally, our results suggested that root and stem functional traits, which are infrequently taken into consideration, were useful to differentiate subtropical coastal plants and, in general, to study plant adaptations to environmental conditions in depth.

中文翻译：

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功能特征揭示了巴西南部短土壤梯度中的沿海植被组装模式

摘要 植物功能性状与土壤变量之间的关系有助于了解植物群落组成和限定植物功能群以突出其对环境条件的适应性。本研究的主要目的是利用沿短土壤梯度的功能特征来解释沿海植被的组装模式。这项工作是在巴西南部沿海低地植被（前缘）的先驱区进行的。我们选择了 40 个与叶、茎和根的形态学和解剖学相关的功能性状，涉及 60 个物种，它们记录在沿着从海岸线到松弛的三个横断面的 25 个植被区中。在每个地块中，收集植物区系和土壤数据，并测量功能性状。我们通过RLQ和第四角分析分析了物种功能性状与土壤因子之间的关系。盐度和有机质含量是前缘植被分化中最重要的土壤因子，而解释植物对沿海环境适应性的最重要性状是株高、厚壁组织、海绵状薄壁组织和根中菊粉的储量。植物的两个功能组被限定：由乔木和灌木形成的保守组占主导地位木本群落，SLA（比叶面积）值低，表皮厚，酚类化合物和晶体的频率高，木本茎和高株高，倾向于投资永久性空中器官；和更多异质的草本植物群（发现于海滩社区，不可泛滥，和湿社区）具有获得性特征（高 SLA 值）或保守策略（根茎和木足）。最后，我们的结果表明，很少考虑的根和茎功能性状有助于区分亚热带沿海植物，并且通常可以深入研究植物对环境条件的适应。