Department of Biology, Faculty of Science, University of Zagreb, Rooseveltov trg 6, 10000 Zagreb, Croatia.
School of Science and Technology, Nottingham Trent University, Nottingham NG11 8NS, UK.
Sci Total Environ. 2022 Jan 15;804:150022. doi: 10.1016/j.scitotenv.2021.150022. Epub 2021 Aug 31.
As complex mosaics of lotic, lentic, and terrestrial habitats, intermittent rivers and ephemeral streams (IRES) support high biodiversity. Despite their ecological importance, IRES are poorly represented in routine monitoring programs, but recent recognition of their considerable-and increasing-spatiotemporal extent is motivating efforts to better represent IRES in ecological status assessments. We examine response patterns of aquatic macroinvertebrate communities and taxa to flow intermittence (FI) across three European climatic regions. We used self-organizing map (SOM) to ordinate and classify sampling sites based on community structure in regions with continental, Mediterranean and oceanic climates. The SOM passively introduced FI, quantified as the mean annual % flow, and visualized its variability across classified communities, revealing a clear association between community structure and FI in all regions. Indicator species analysis identified taxa indicative of low, intermediate and high FI. In the continental region, the amphipod Niphargus was indicative of high FI and was associated with groundwater-fed IRES, whereas indicators of Mediterranean IRES comprised Odonata, Coleoptera and Heteroptera taxa, which favor lentic conditions. In the oceanic region, taxa indicative of relatively high FI included leuctrid stoneflies and a limnephilid caddisfly, likely reflecting the colonization of IRES by aerial adults from nearby perennial reaches. The Diptera families Chironomidae and Simuliidae showed contrasting FI preferences among regions, reflecting environmental heterogeneity between regions and the coarse taxonomic resolution to which these organisms were identified. These region-specific community and taxon responses of aquatic biota to FI highlight the need to adapt standard biotic indices to enable effective ecological status assessments in IRES.
作为流态、静水和陆地栖息地的复杂镶嵌体，间歇性河流和短暂河流（IRES）支持着高度的生物多样性。尽管它们具有重要的生态意义，但在常规监测计划中，IRES 的代表性很差，但最近对其相当大的——而且日益增加的——时空范围的认识，正在促使人们努力更好地在生态状况评估中代表 IRES。我们考察了水生大型无脊椎动物群落和类群对三个欧洲气候区的间歇性水流（FI）的反应模式。我们使用自组织映射（SOM）根据具有大陆性、地中海性和海洋性气候的区域的群落结构对采样点进行排序和分类。SOM 被动地引入了 FI，其量化为年平均流量的%，并在分类群落中可视化其变化，这揭示了在所有地区，群落结构与 FI 之间存在明显的关联。指示物种分析确定了指示低、中和高 FI 的类群。在大陆地区，片脚类动物 Niphargus 是高 FI 的指示物种，与地下水补给的 IRES 有关，而地中海 IRES 的指示物种包括蜻蜓目、鞘翅目和半翅目，这些物种有利于静水条件。在海洋地区，指示相对高 FI 的类群包括石蝇目和鳞翅目石蛾，这可能反映了来自附近常年河段的成虫对 IRES 的殖民化。双翅目科的摇蚊科和毛翅目科在不同地区表现出不同的 FI 偏好，反映了不同地区的环境异质性和这些生物被鉴定的粗分类分辨率。水生生物对 FI 的这些特定于区域的群落和类群反应突出了需要适应标准生物指标，以实现 IRES 的有效生态状况评估。
