Unified models of biological diversity across organizational levels (genes, species, communities) provide key insight into fundamental ecological processes. Theory predicts that the strength of the correlation between species abundance and genetic diversity should be related to community age in closed communities (i.e. abundant species accumulate more genetic diversity over time than rare species). Following this rationale, we hypothesize that historical climatic events are expected to impact assembly processes, hence affecting both the species abundance distribution (SAD) and the species genetic distribution (SGD) in continental communities. Therefore, we predict that, if the congruence between SADs and SGDs depends on community age, then higher congruence would be observed in localities where climate has been more stable since the Last Glacial Maximum (LGM). We tested this prediction using relative abundance and nucleotide diversity (cox1-5′) data from 20 communities of leaf beetles along a latitudinal transect in the Iberian Peninsula. We observed that the congruence between SAD and SGD curves, measured as the correlation between the species' rank orders in both distributions, was significantly related to the change in mean annual temperature since the LGM, but not to current climatic conditions. Our results suggest that, despite the high connectivity of continental communities, historical climatic stability is still a relevant predictor of the congruence between species abundance and genetic diversity. Hence, the degree of congruence between SADs and SGDs could be used as a proxy of community stability, related not only to historical climatic variation but also to any other disrupting factors, including human pressure.

中文翻译：

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气候稳定性预测物种丰富度和遗传多样性之间的一致性

跨组织层面（基因、物种、群落）的生物多样性统一模型提供了对基本生态过程的关键洞察。理论预测，物种丰度和遗传多样性之间的相关性强度应与封闭群落中的群落年龄有关（即随着时间的推移，丰富的物种比稀有物种积累更多的遗传多样性）。根据这个基本原理，我们假设历史气候事件预计会影响聚集过程，从而影响大陆群落的物种丰度分布（SAD）和物种遗传分布（SGD）。因此，我们预测，如果 SAD 和 SGD 之间的一致性取决于群落年龄，那么在末次盛冰期 (LGM) 以来气候更加稳定的地区将会观察到更高的一致性。我们使用来自伊比利亚半岛纬度样带的 20 个叶甲虫群落的相对丰度和核苷酸多样性 ( cox1 -5') 数据测试了这一预测。我们观察到，SAD 和 SGD 曲线之间的一致性（以两种分布中物种排名顺序之间的相关性来衡量）与末次盛冰期以来年平均气温的变化显着相关，但与当前的气候条件无关。我们的结果表明，尽管大陆群落具有高度连通性，但历史气候稳定性仍然是物种丰富度和遗传多样性之间一致性的相关预测因素。因此，SAD 和 SGD 之间的一致性程度可以作为群落稳定性的指标，不仅与历史气候变化有关，还与任何其他干扰因素（包括人类压力）有关。