Freijeiro Andrea, Baselga Andrés
Departamento de Zoología, Facultad de Biología, Universidad de Santiago de Compostela, c/ Lope Gómez de Marzoa s/n, 15782 Santiago de Compostela, Spain.
Zookeys. 2016 Jun 9(597):81-99. doi: 10.3897/zookeys.597.6792. eCollection 2016.
Despite some general concordant patterns (i.e. the latitudinal richness gradient), species richness and composition of different European beetle taxa varies in different ways according to their dispersal and ecological traits. Here, the patterns of variation in species richness, composition and spatial turnover are analysed in European cryptocephaline and chrysomeline leaf beetles, assessing their environmental and spatial correlates. The underlying rationale to use environmental and spatial variables of diversity patterns is to assess the relative support for niche- and dispersal-driven hypotheses. Our results show that despite a broad congruence in the factors correlated with cryptocephaline and chrysomeline richness, environmental variables (particularly temperature) were more relevant in cryptocephalines, whereas spatial variables were more relevant in chrysomelines (that showed a significant longitudinal gradient besides the latitudinal one), in line with the higher proportion of flightless species within chrysomelines. The variation in species composition was also related to environmental and spatial factors, but this pattern was better predicted by spatial variables in both groups, suggesting that species composition is more linked to dispersal and historical contingencies than species richness, which would be more controlled by environmental limitations. Among historical factors, Pleistocene glaciations appear as the most plausible explanation for the steeper decay in assemblage similarity with spatial distance, both in cryptocephalines and chrysomelines.
尽管存在一些总体一致的模式（即纬度丰富度梯度），但不同欧洲甲虫类群的物种丰富度和组成会因其扩散和生态特征而以不同方式变化。在此，我们分析了欧洲隐头叶甲科和叶甲科叶甲的物种丰富度、组成和空间周转率的变化模式，评估它们与环境和空间的相关性。利用多样性模式的环境和空间变量的基本原理是评估对生态位驱动假说和扩散驱动假说的相对支持。我们的结果表明，尽管与隐头叶甲科和叶甲科丰富度相关的因素有广泛的一致性，但环境变量（特别是温度）在隐头叶甲科中更相关，而空间变量在叶甲科中更相关（叶甲科除了纬度梯度外还显示出显著的经度梯度），这与叶甲科中不能飞的物种比例较高一致。物种组成的变化也与环境和空间因素有关，但两组中这种模式都由空间变量更好地预测，这表明物种组成比物种丰富度更与扩散和历史偶然性相关，物种丰富度更多地受环境限制的控制。在历史因素中，更新世冰川作用似乎是隐头叶甲科和叶甲科中组合相似性随空间距离急剧下降的最合理的解释。
