1. Plot‐level redundancy or alpha redundancy is usually defined as the fraction of species diversity not expressed by functional or phylogenetic diversity. Redundancy is zero when all species in one plot are maximally dissimilar from each other. In contrast, redundancy tends to its maximum if the functional or phylogenetic differences between species tend to be minimal.
2. To explore the ecological drivers of community assembly, ecologists also use dissimilarity measures between pairs of plots (a component of beta diversity). Traditional dissimilarity measures summarize compositional differences between pairs of plots based either on species presence and absence data or on species abundances, thus attributing equal distinctiveness between any two species.
3. In the last decades a number of dissimilarity measures which incorporate information on functional or phylogenetic differences among species have been proposed. On the basis of such improved measures, we can define an index of beta redundancy for a pair of plots as the fraction of species dissimilarity not expressed by functional or phylogenetic dissimilarity.
4. A necessary condition to get a meaningful index of beta redundancy is that for a given pair of plots, the functional or phylogenetic dissimilarity is always lower or equal to the corresponding species dissimilarity. However, many of the existing indices of functional or phylogenetic dissimilarity can lead to values greater than for species dissimilarity.
5. The aim of this paper was thus to introduce a new family of tree‐based measures of phylogenetic and functional dissimilarity that conform to this requirement. To show the behaviour of the proposed measures, a worked example with data on Alpine vegetation is used.

中文翻译：

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从alpha到beta的功能和系统发育冗余

1. 地块级冗余或alpha冗余通常定义为物种多样性的一部分，而功能或系统发育多样性则无法表达。当一个图中的所有物种彼此之间最大相似时，冗余度为零。相反，如果物种之间的功能或系统发育差异趋于最小，则冗余趋于最大化。
2. 为了探索社区集会的生态驱动力，生态学家还使用成对的地块（β多样性的组成部分）之间的差异度量。传统的差异度量基于物种的存在和缺乏数据或物种的丰度来总结成对地块之间的成分差异，从而在任意两个物种之间赋予相同的独特性。
3. 在过去的几十年中，已经提出了许多种不同措施，这些措施结合了物种间功能或系统发育差异的信息。基于此类改进措施，我们可以将一对样地的β冗余指标定义为物种相似性的一部分，该部分不由功能或系统发育相似性表示。
4. 获得有意义的beta冗余指标的必要条件是，对于给定的一对图，功能或系统发育上的不相似始终低于或等于相应物种的不相似。但是，许多现有的功能或系统发育相似性指标可能会导致值大于物种相似性。
5. 因此，本文的目的是介绍符合该要求的新的基于树的系统发育和功能不相似性度量标准系列。为了显示建议措施的行为，使用了一个有关高山植被数据的实例。