Institute of Science and the Environment, University of Worcester, Henwick Grove, Worcester WR2 6AJ, UK.
Institute of Science and the Environment, University of Worcester, Henwick Grove, Worcester WR2 6AJ, UK.
Sci Total Environ. 2018 Jul 1;628-629:1308-1316. doi: 10.1016/j.scitotenv.2018.02.162. Epub 2018 Feb 20.
Intermittent rivers are temporally dynamic, shifting between lotic, lentic (ponding) and dry habitat phases, yet almost all research effort has focussed on the lotic phase, with limited research attention on the lentic and dry phases. Information regarding the biological diversity of the lentic phase is vital to quantify the total aquatic biodiversity, their use as flow refugia, and the long-term conservation and management of intermittent rivers. In this study, we compared the diversity and composition of macroinvertebrates from perennial, intermittent and ponded sites in two intermittent rivers in the United Kingdom. We examined whether instream ponding provided refugia for lotic taxa and a habitat for newly colonising taxa. A total of 129 taxa (perennial - 86, intermittent - 82, ponding - 78) were recorded. Instream ponds were found to support heterogeneous communities compared to flowing sites. Twenty-two percent of taxa were recorded only from ponded sites, many of which were lentic specialists, while 38% of taxa persisted in instream ponds after flow had ceased. Results from this study highlight that instream ponds provide an important flow refuge for macroinvertebrates including rheophilic taxa, which move into instream ponds when channels become longitudinally disconnected, and makes a significant contribution to aquatic diversity in intermittent rivers, providing suitable habitat for newly colonising taxa. Aquatic diversity in intermittent rivers may have been underestimated historically, failing to acknowledge the ecological contribution of the lentic phase. Incorporating the ponding phase alongside the lotic phase will ensure the total aquatic biodiversity of intermittent rivers is quantified and effective biodiversity conservation and management strategies are employed.
间歇性河流在时间上是动态的，在急流、静水（池塘）和干燥生境阶段之间不断变化，但几乎所有的研究都集中在急流阶段，对静水和干燥阶段的研究关注有限。关于静水阶段生物多样性的信息对于量化总水生生物多样性、将其用作水流避难所，以及长期保护和管理间歇性河流至关重要。在这项研究中，我们比较了英国两条间歇性河流中永久性、间歇性和池塘化地点的大型无脊椎动物多样性和组成。我们研究了溪流池塘是否为激流分类群提供了避难所，并为新殖民分类群提供了栖息地。共记录到 129 个分类群（永久性-86，间歇性-82，池塘化-78）。与流动地点相比，溪流池塘中的池塘中发现存在异质群落。有 22%的分类群仅从池塘化地点记录到，其中许多是静水专性种，而 38%的分类群在水流停止后仍存在于溪流池塘中。这项研究的结果表明，溪流池塘为包括洄游性分类群在内的大型无脊椎动物提供了重要的水流避难所，当河道纵向断开时，这些分类群会进入溪流池塘，并且对间歇性河流的水生多样性做出了重要贡献，为新殖民分类群提供了适宜的栖息地。历史上，间歇性河流的水生多样性可能被低估了，没有认识到静水阶段的生态贡献。将池塘化阶段与急流阶段结合起来，可以确保量化间歇性河流的总水生生物多样性，并采用有效的生物多样性保护和管理策略。
