Department of Hydrochemistry and Ecosystem Modelling, Institute of Hydrobiology, Biology Centre, Czech Academy of Sciences, Na Sádkách 702/7, CZ-370 05 České Budějovice, Czech Republic.
Faculty of Natural Sciences, Matej Bel University, Tajovského 40, SK-974 01 Banská Bystrica, Slovakia.
Environ Entomol. 2024 Aug 17;53(4):604-618. doi: 10.1093/ee/nvae052.
Chironomids of the genus Diamesa (Meigen, 1835, Diptera: Chironomidae) inhabit cold, oxygen-rich running waters. We have investigated the presence of Diamesa and other freshwater macroinvertebrates at 22 stream sampling sites in 3 European high mountain regions (the Central Pyrenees, the Ötztal Alps, and the Tatra Mountains) to establish suitable temperature conditions for Diamesa dominance. It has been generally accepted that their high abundance was linked to the presence of glaciers; however, we have shown that in the Tatra Mountains, where there are no glaciers, the conditions for the dominance of Diamesa species are created due to permanent snowfields, the geographical orientation of the valley and shading by the surrounding high peaks. The historical connection of Diamesa to glaciers was investigated from the paleolimnological records of subfossil chironomid assemblages from the Bohemian Forest, where glaciers disappeared before or during the Late Glacial period. As expected, water temperature seems to be the main driver of Diamesa distribution, and we determined that the relative abundance of Diamesa species was significantly higher at the sites with a mean July water temperature below 6.5 °C. The Diamesa-dominated stream communities seems to be endangered due to ongoing climate warming and this assumption is supported by our paleolimnological results from the Bohemian Forest lakes, where Diamesa has disappeared due to warming of lake inflows at the beginning of the Holocene. These findings strengthen the former suggestions that some Diamesa species could be used as an indicator for tracking recent environmental changes in vulnerable ecosystems of cold mountain streams.
双翅目摇蚊科的狄氏摇蚊属（Meigen，1835 年）栖息于寒冷、富氧的流水环境中。我们在欧洲 3 个高山地区（比利牛斯山脉、奥茨塔尔阿尔卑斯山脉和塔特拉山脉）的 22 个溪流采样点调查了狄氏摇蚊属和其他淡水大型无脊椎动物的存在情况，以确定狄氏摇蚊属优势种群存在的适宜温度条件。人们普遍认为，它们的高丰度与冰川的存在有关；然而，我们已经表明，在没有冰川的塔特拉山脉，由于永久性雪地、山谷的地理位置和周围高峰的遮蔽作用，创造了狄氏摇蚊属物种优势的条件。狄氏摇蚊与冰川的历史联系是从波希米亚森林的亚化石摇蚊组合的古湖泊学记录中调查的，在那里冰川在末次冰期之前或期间就已经消失了。正如预期的那样，水温似乎是狄氏摇蚊分布的主要驱动因素，我们确定在 7 月平均水温低于 6.5°C 的地点，狄氏摇蚊属物种的相对丰度明显更高。由于持续的气候变暖，狄氏摇蚊主导的溪流群落似乎受到了威胁，我们从波希米亚森林湖泊的古湖泊学结果中得到了支持，在那里，由于全新世早期湖泊流入的变暖，狄氏摇蚊已经消失。这些发现进一步证实了一些狄氏摇蚊属物种可以作为追踪脆弱高山溪流生态系统近期环境变化的指示物的观点。
