Ackerly D D, Cornwell W K
Department of Integrative Biology, University of California, Berkeley, CA 94720, USA.
Ecol Lett. 2007 Feb;10(2):135-45. doi: 10.1111/j.1461-0248.2006.01006.x.
Plant functional traits vary both along environmental gradients and among species occupying similar conditions, creating a challenge for the synthesis of functional and community ecology. We present a trait-based approach that provides an additive decomposition of species' trait values into alpha and beta components: beta values refer to a species' position along a gradient defined by community-level mean trait values; alpha values are the difference between a species' trait values and the mean of co-occurring taxa. In woody plant communities of coastal California, beta trait values for specific leaf area, leaf size, wood density and maximum height all covary strongly, reflecting species distributions across a gradient of soil moisture availability. Alpha values, on the other hand, are generally not significantly correlated, suggesting several independent axes of differentiation within communities. This trait-based framework provides a novel approach to integrate functional ecology and gradient analysis with community ecology and coexistence theory.
植物功能性状不仅会随着环境梯度发生变化，而且在占据相似条件的物种之间也存在差异，这给功能生态学和群落生态学的综合研究带来了挑战。我们提出了一种基于性状的方法，该方法能将物种的性状值加性分解为α和β组分：β值指一个物种在由群落水平平均性状值定义的梯度上的位置；α值是一个物种的性状值与同时出现的分类群平均值之间的差异。在加利福尼亚海岸的木本植物群落中，比叶面积、叶片大小、木材密度和最大高度的β性状值都呈现出强烈的共变关系，反映了物种在土壤水分可利用性梯度上的分布情况。另一方面，α值通常没有显著的相关性，这表明群落内部存在几个独立的分化轴。这种基于性状的框架为将功能生态学和梯度分析与群落生态学及共存理论相结合提供了一种新方法。
