The heterogeneity-biodiversity relationship across taxa and ecosystems

环境异质性是指一定区域内资源或结构的时空变化。异质性-多样性假说是生态学的经典，以至于自然资源保护者在强调保护或恢复不同栖息地类型的重要性时，为正向关系辩护已经变得司空见惯。然而，最近的理论和观察表明，这种关系可以是积极的、平坦的，甚至是消极的，这取决于生态环境。虽然植物和动物的多样性直观地依赖于景观尺度上的环境异质性，但尚不清楚这种关系是否概括了林分尺度。另一种观点认为，异质性-多样性关系消失了，甚至可能在林分尺度上发生逆转(多样性产生异质性)。先驱者的工作以及最近的研究都系统地考虑了一个关系方向：异质性产生多样性。到目前为止，植物多样性如何在林分尺度上决定环境异质性的问题一直被忽视。

Environmental heterogeneity is defined as the spatial and temporal change in resource or structure within a given area. The heterogeneity-diversity hypothesis is a classic of ecology, to the degree that it has become commonplace for conservationists to plead the positive relationship when emphasizing the importance of preserving or restoring different habitat types. However, recent theory and observation suggest that the relationship can be positive, flat, or even negative, depending on the ecological context. While plant and animal diversity intuitively depend on environmental heterogeneity at the landscape-scale, it is unclear whether the relationship generalizes the stand-scale. An alternative view is that the heterogeneity-diversity relationship vanishes and may even be reversed (diversity begets heterogeneity) at the stand-scale. Pioneer work as well as more recent studies have systematically considered one relationship direction; that heterogeneity begets diversity. The question of how plant diversity determines environmental heterogeneity at the stand-scale has, so far, been overlooked.