Centre for Ecological Research, Balaton Limnological Institute, Klebelsberg K. u. 3, H-8237 Tihany, Hungary; Centre for Ecological Research, GINOP Sustainable Ecosystems Group, Klebelsberg K. u. 3, H-8237 Tihany, Hungary.
Centre for Ecological Research, Balaton Limnological Institute, Klebelsberg K. u. 3, H-8237 Tihany, Hungary.
Sci Total Environ. 2020 Dec 15;748:141407. doi: 10.1016/j.scitotenv.2020.141407. Epub 2020 Aug 8.
We examined the effects of regional scale land use and local scale environmental and biotic stressors on alpha, beta and zeta diversities of native fish communities in wadeable streams and non-wadeable rivers in the Danube basin, Hungary. Relationships among land use and local scale environmental and biotic stressors were weak both in streams and rivers, suggesting that these stressors act relatively independently. Alpha diversity decreased strongly with increasing local scale environmental stressor intensity in rivers. On the contrary, its response to stressors was more obscure in streams, where the best-fit statistical model indicated the importance of the interaction between land use, local scale environmental and biotic stressors, while the secondly ranked model highlighted the negative impact of local scale environmental stressors. Analysis of variance using distance matrices provided evidence that stressors alone and in interactions explained compositional differences of pairs of study sites (beta diversity). Considering the degree of overall degradation, both local (alpha) and among-site (beta and zeta) diversity indices responded to increasing stressor intensity, generally negatively. Riverine fish communities showed higher degrees of similarity (lower beta and higher zeta) than stream fish communities. They also showed increasing similarity (i.e. homogenization) with increasing overall stressor intensity, unlike stream fish communities, which showed no relationship with overall stressor intensity. Our results suggest that the relationships between land use and local scale environmental and biotic stressors can be complex and so do their effects on biodiversity. While stressor specific indices can provide information on the role of specific stressors in some cases, the examination of overall stressor effects is needed to assess realistically the effects of anthropogenic disturbances on native fish diversity. Diversity indices that quantify among-site changes in species composition, such as measures of beta and zeta diversity, can be fruitful for better understanding the role of multiple stressors in structuring ecological communities.
我们研究了匈牙利多瑙河流域可涉溪流和不可涉河流中原生鱼类群落的α、β和ζ多样性与区域尺度土地利用及局部尺度环境和生物胁迫因子的关系。在溪流和河流中，土地利用与局部尺度环境和生物胁迫因子之间的关系都很微弱，表明这些胁迫因子相对独立地起作用。在河流中，α多样性随局部尺度环境胁迫因子强度的增加而强烈下降。相反，在溪流中，其对胁迫因子的响应更为模糊，最佳拟合的统计模型表明土地利用、局部尺度环境和生物胁迫因子之间相互作用的重要性，而其次的模型则突出了局部尺度环境胁迫因子的负面影响。使用距离矩阵的方差分析提供了证据，表明胁迫因子单独以及相互作用解释了研究地点对之间的组成差异（β多样性）。考虑到整体退化程度，局部（α）和站点间（β和 ζ）多样性指数都对胁迫因子强度的增加做出了反应，通常为负面反应。与溪流鱼类群落相比，河流鱼类群落表现出更高的相似性（更低的β和更高的 ζ）。它们还随着整体胁迫因子强度的增加而表现出相似性的增加（即同质化），而不像溪流鱼类群落，它们与整体胁迫因子强度没有关系。我们的研究结果表明，土地利用与局部尺度环境和生物胁迫因子之间的关系可能很复杂，它们对生物多样性的影响也是如此。虽然特定胁迫因子的指数可以在某些情况下提供特定胁迫因子作用的信息，但需要检查整体胁迫因子的影响，以现实地评估人为干扰对本地鱼类多样性的影响。量化物种组成站点间变化的多样性指数，如β和 ζ多样性的度量，可以有助于更好地理解多种胁迫因子在生态群落结构中的作用。
