Scheiner Samuel M, Kosman Evsey, Presley Steven J, Willig Michael R
Division of Environmental Biology National Science Foundation Arlington VA USA.
Institute for Cereal Crops Improvement Tel Aviv University Tel Aviv Israel.
Ecol Evol. 2017 Jul 10;7(16):6444-6454. doi: 10.1002/ece3.3199. eCollection 2017 Aug.
We present a framework for biodiversity metrics that organizes the growing panoply of metrics. Our framework distinguishes metrics based on the type of information-abundance, phylogeny, function-and two common properties-magnitude and variability. Our new metrics of phylogenetic diversity are based on a partition of the total branch lengths of a cladogram into the proportional share of each species, including: a measure of divergence which standardizes the amount of evolutionary divergence by species richness and time depth of the cladogram; a measure of regularity which is maximal when the tree is perfectly symmetrical so that all species have the same proportional branch lengths; a measure that combines information on the magnitude and variability of abundance with phylogenetic variability, and a measure of phylogenetically weighted effective mean abundance; and indicate how those metrics can be decomposed into α and β components. We illustrate the utility of these new metrics using empirical data on the bat fauna of Manu, Peru. Divergence was greatest in lowland rainforest and at the transition between cloud and elfin forests, and least in upper elfin forests and in cloud forests. In contrast, regularity was greatest in lowland rainforest, dipping to its smallest values in mid-elevation cloud forests, and then increasing in high elevation elfin forests. These patterns indicate that the first species to drop out with increasing elevation are ones that are closely related to other species in the metacommunity. Measures of the effective number of phylogenetically independent or distinct species decreased very rapidly with elevation, and β-diversity was larger. In contrast, a comparison of feeding guilds shows a different effect of phylogenetic patterning. Along the elevational gradient, each guild generally loses some species from each clade-rather than entire clades-explaining the maintenance of functional diversity as phylogenetic diversity decreases.
我们提出了一个生物多样性指标框架，该框架对日益繁多的指标进行了整理。我们的框架根据信息类型（丰富度、系统发育、功能）以及两个共同属性（数量和变异性）来区分指标。我们新的系统发育多样性指标基于将系统发育树的总分支长度划分为每个物种的比例份额，包括：一种分化度量，通过物种丰富度和系统发育树的时间深度对进化分化量进行标准化；一种规则性度量，当树完全对称时最大，即所有物种具有相同的比例分支长度；一种将丰富度的数量和变异性信息与系统发育变异性相结合的度量，以及一种系统发育加权有效平均丰富度的度量；并指出这些指标如何分解为α和β成分。我们使用秘鲁马努地区蝙蝠动物群的实证数据说明了这些新指标的实用性。分化在低地雨林以及云雾林和侏儒林的过渡地带最大，而在上层侏儒林和云雾林中最小。相比之下，规则性在低地雨林中最大，在中海拔云雾林中降至最小值，然后在高海拔侏儒林中增加。这些模式表明，随着海拔升高首先消失的物种是那些与集合群落中的其他物种密切相关的物种。系统发育上独立或不同物种的有效数量度量随着海拔升高下降非常迅速，并且β多样性更大。相比之下，对取食类群的比较显示了系统发育模式的不同影响。沿着海拔梯度，每个类群通常从每个进化枝中失去一些物种，而不是整个进化枝，这解释了随着系统发育多样性降低功能多样性仍得以维持的原因。
