Recent studies have found that local-scale plots measured through time exhibit marked variation in the change in species richness. However, the overall effect often reveals no net change. Most studies to date have been agnostic about the identities of the species lost/gained and about the processes that might lead to these changes. Generalist traits might be crucial in allowing species to colonize new plots or remain resilient in situ, whereas environmental filtering might remove specialists. We test whether plots are changing in species richness, whether they are becoming more similar (i.e., becoming homogenized) through time and whether several generalist traits can predict gains or losses from local plots.

中文翻译：

---

地理同质化，但加拿大蝴蝶当地丰富度几乎没有净变化

最近的研究发现，随时间测量的局部尺度地块在物种丰富度变化方面表现出显着变化。然而，整体效果往往没有显示出净变化。迄今为止，大多数研究都对失去/获得的物种的身份以及可能导致这些变化的过程不可知。通才特征可能对允许物种在新地块上定居或保持原地弹性至关重要，而环境过滤可能会淘汰专家。我们测试地块是否在物种丰富度方面发生变化，它们是否随着时间变得更加相似（即变得同质化），以及几个通用特征是否可以预测本地地块的收益或损失。