Department of Botany and Zoology, Faculty of Science, Masaryk University, Brno, Czechia.
Conservatoire Botanique National de Franche-Comté - Observatoire Régional des Invertébrés, Besançon, France.
Sci Total Environ. 2021 Aug 20;783:146910. doi: 10.1016/j.scitotenv.2021.146910. Epub 2021 Apr 6.
Human activities have enormous impact on current biodiversity distribution across all spatial scales. Despite the numerous studies showing the difference between preserved and impaired sites, only little is known about the regional scale. Therefore, we selected four European regions differing in habitat conservation status (HCS) to explore if the variation in land snail communities reflects regional differences. We collected quantitative land snail samples at 169 isolated spring fen sites and measured environmental parameters. The species richness of habitat specialists expressed low variation and weak associations with local conditions in the two regions of adequate HCS, presumably because of their common occurrence throughout most sites. In contrast, the richness of matrix-derived species, i.e. predominantly habitat generalists, was highly variable in these two regions and also tightly associated with local conditions, especially moisture. In both the intermediate and the inadequate HCS region, these associations were much weaker as the fens are less extreme and allow for penetration of matrix-derived species. Population densities of Vertigo geyeri, an umbrella species internationally protected by the EU Habitats Directive, were highest in the two adequate HCS regions. Species composition was primarily controlled by moisture in the regions of adequate HCS, while in the remaining regions, those predictors that are less easily jeopardized by human impact, such as climate, water chemistry and terrain topography, gained importance. In the inadequate HCS region, none of the analysed predictors was associated with the main compositional gradient, suggesting a complete disruption of community-environment relationships. Our results suggest that the species richness and community responses to natural gradients might be substantially modified by human impact, although the effect of some other region-specific factors cannot be easily disentangled because of inevitably low number of studied regions.
人类活动对当前生物多样性在所有空间尺度上的分布都有着巨大的影响。尽管有许多研究表明了保护区和受损区之间的差异，但对于区域尺度的了解却很少。因此，我们选择了四个在生境保护状况（HCS）方面存在差异的欧洲地区，以探索陆地蜗牛群落的变化是否反映了区域差异。我们在 169 个孤立的春季泉湿地站点收集了定量的陆地蜗牛样本，并测量了环境参数。在 HCS 状况良好的两个地区，生境专化种的物种丰富度变化较小，与当地条件的关联较弱，这可能是因为它们在大多数地点都普遍存在。相比之下，基质衍生种（主要是生境广适种）的丰富度在这两个地区变化很大，与当地条件（特别是湿度）紧密相关。在 HCS 状况中等和较差的两个地区，这些关联较弱，因为湿地不那么极端，允许基质衍生种渗透。受欧盟生境指令国际保护的伞物种 Vertigo geyeri 的种群密度在 HCS 状况良好的两个地区最高。物种组成主要由 HCS 状况良好的地区的湿度控制，而在其余地区，那些不太容易受到人类影响威胁的预测因子，如气候、水化学和地形地形，变得更加重要。在 HCS 状况较差的地区，没有一个分析的预测因子与主要的组成梯度相关，这表明群落与环境的关系完全被打乱。我们的研究结果表明，物种丰富度和群落对自然梯度的反应可能会受到人类活动的显著影响，尽管由于研究区域数量不可避免地较少，其他一些特定区域因素的影响可能难以区分。
