The relationship between biodiversity and spectral diversity is highly scale-dependent, and temporal variation in leaf morphological, biochemical traits and canopy structure can alter this relationship. However, the temporal dependence of the spectral diversity – biodiversity relationship is poorly understood, in part due to the difficulties of obtaining consistent measurements across space and time. Using leaf pigments and leaf and canopy reflectance throughout a growing season in the Cedar Creek prairie biodiversity experiment, we explored phenological effects on the scale dependence of the spectral biodiversity – biodiversity relationship. Leaf reflectance spectra displayed larger among-species variation than leaf pigments, indicating that leaf reflectance contained more information for distinguishing species than some leaf trait measurements. At the canopy scale, spectral variation derived using reflectance was mainly driven by among-species variation. The canopy scale spectral diversity was also influenced by changing vegetation percent cover, key phenological events (e.g., flowering), and disturbance (drought). Our results revealed that contrasting phenological patterns of spectral diversity metrics emerged at leaf and canopy scales. Because a misunderstanding of these contrasting temporal effects across spatial scales can lead to possible misinterpretations of the spectral diversity – biodiversity relationship or of their underlying causes, more research effort is needed to understand these cross-scale temporal effects.

生物多样性和光谱多样性之间的关系高度依赖于尺度，叶片形态、生化性状和冠层结构的时间变化可以改变这种关系。然而，人们对光谱多样性与生物多样性关系的时间依赖性知之甚少，部分原因是难以在空间和时间上获得一致的测量结果。在 Cedar Creek 草原生物多样性实验中，使用整个生长季节的叶子色素和叶子和冠层反射率，我们探索了物候对光谱生物多样性 - 生物多样性关系的尺度依赖性的影响。叶反射光谱显示出比叶色素更大的种间变异，表明叶反射比某些叶性状测量包含更多用于区分物种的信息。在冠层尺度上，使用反射率得出的光谱变化主要由种间变化驱动。冠层尺度光谱多样性也受到植被覆盖率变化、关键物候事件（例如开花）和干扰（干旱）的影响。我们的研究结果表明，光谱多样性指标的对比物候模式出现在叶子和冠层尺度上。由于对这些跨空间尺度的对比时间效应的误解可能导致对光谱多样性——生物多样性关系或其根本原因的误解，因此需要更多的研究工作来理解这些跨尺度的时间效应。冠层尺度光谱多样性也受到植被覆盖率变化、关键物候事件（例如开花）和干扰（干旱）的影响。我们的研究结果表明，光谱多样性指标的对比物候模式出现在叶子和冠层尺度上。由于对这些跨空间尺度的对比时间效应的误解可能导致对光谱多样性——生物多样性关系或其根本原因的误解，因此需要更多的研究工作来理解这些跨尺度的时间效应。冠层尺度光谱多样性也受到植被覆盖率变化、关键物候事件（例如开花）和干扰（干旱）的影响。我们的研究结果表明，光谱多样性指标的对比物候模式出现在叶子和冠层尺度上。由于对这些跨空间尺度的对比时间效应的误解可能导致对光谱多样性——生物多样性关系或其根本原因的误解，因此需要更多的研究工作来理解这些跨尺度的时间效应。