Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB), Müggelseedamm 301, 12587 Berlin, Germany.
Helmholtz Centre for Environmental Research GmbH - UFZ, Brückstr. 3a, 39114 Magdeburg, Germany.
Sci Total Environ. 2020 Nov 15;743:140582. doi: 10.1016/j.scitotenv.2020.140582. Epub 2020 Jul 2.
The composition of littoral macroinvertebrate communities in lakes is governed by multiple natural and anthropogenic environmental influences interacting at different spatial scales. Since ecological assessment methods using littoral macroinvertebrates should respond specifically to a single stressor, knowledge on the unique effects of a given stressor is necessary. To effectively disentangle the effects of hydromorphology and trophic state requires analysing macroinvertebrate communities at lake sites with the full range of both stressors. We used a dataset of 98 lakes encompassing the entire gradient of geographical locations, lake types, hydromorphological degradation and trophic states in Central European lakes. We studied the unique and joint effects of hydromorphology and trophic state on macroinvertebrate richness, community composition and the Littoral Invertebrate Multimetric Index based on Composite Sampling (LIMCO). Variation partitioning analyses were conducted to test the importance of hydromorphology relative to trophic state across and within hydromorphological states (natural shorelines, hard and soft shore modifications) and trophic states (oligotrophic to hypertrophic states). At natural, hard and soft modification sites, hydromorphology explained 10, 16 and 19%, respectively, of the average unique variation of diversity, community composition and the LIMCO index, whereas trophic state explained on average 2, 5 and 5%, respectively. Similarly, in low, medium and high trophic state lakes, hydromorphology explained 10, 15 and 7%, respectively, of the average unique variation of diversity, community composition and the LIMCO index, whereas trophic state explained on average 0.3, 3 and 6%, respectively. Our results demonstrate that littoral hydromorphology was a more important driver of macroinvertebrate diversity, community composition and LIMCO than trophic state across hydromorphological states and trophic states. This indicates that multiple stressors in lakes act hierarchically on littoral macroinvertebrate communities and that the hydromorphological degradation of littoral zones is the primary driver for altered communities.
湖泊沿岸大型无脊椎动物群落的组成受多种自然和人为环境影响的控制，这些影响在不同的空间尺度上相互作用。由于使用沿岸大型无脊椎动物进行生态评估的方法应该专门针对单一胁迫因素做出响应，因此需要了解给定胁迫因素的独特影响。为了有效地厘清水形态和营养状态的影响，需要在具有这两种胁迫因素的全范围的湖泊站点上分析大型无脊椎动物群落。我们使用了一个包含中欧湖泊的地理位置、湖泊类型、水形态退化和营养状态的整个梯度的 98 个湖泊数据集。我们研究了水形态和营养状态对大型无脊椎动物丰富度、群落组成以及基于综合采样的沿岸无脊椎动物多指标综合评价指数（LIMCO）的独特和共同影响。我们进行了变异划分分析，以测试水形态相对于营养状态在整个水形态状态（自然岸线、硬岸和软岸改造）和营养状态（贫营养到富营养状态）内和跨状态的重要性。在自然、硬岸和软岸改造点，水形态分别解释了多样性、群落组成和 LIMCO 指数的平均独特变异的 10%、16%和 19%，而营养状态分别解释了平均 2%、5%和 5%。同样，在低、中、高营养状态的湖泊中，水形态分别解释了多样性、群落组成和 LIMCO 指数的平均独特变异的 10%、15%和 7%，而营养状态分别解释了平均 0.3%、3%和 6%。我们的研究结果表明，在整个水形态状态和营养状态范围内，与营养状态相比，水形态是沿岸大型无脊椎动物多样性、群落组成和 LIMCO 的更重要驱动因素。这表明，湖泊中的多种胁迫因素对沿岸大型无脊椎动物群落的作用是等级式的，而沿岸带的水形态退化是群落改变的主要驱动因素。
