Prehliadanie podľa Autor "Novikmec, Milan"
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Položka Chironomidae (Diptera) from mountain lakes of the Eastern Carpathians, Romania: first records and insight into diversity(Pensoft Publishers : Sofia, 2025) Bitušík, Peter; Slobodníková, Veronika; Novikmec, Milan; Dudáš, Adam; Hamerlík, LadislavLakes at high altitudes are extremely sensitive to environmental stressors at both local and global scales, making them important sentinels of the changing world. Chironomidae, the most diverse group of benthic macroinvertebrates inhabiting mountain lakes, respond to various environmental impacts, making them important bioindicators of the lake’s ecological status. This study aimed to provide the first insight into chironomid diversity in high-altitude lakes from two mountain ranges of the Romanian Eastern Carpathians: the Maramures, and the Rodna Mountains. Floating chironomid material was collected by skimming the water surface with a hand net from 16 lakes at elevations ranging from 1378 to 1922 m a.s.l. A total of 50 species/ taxa were collected, including nine new records for Romania. Notes on newly recorded species’ distribution, ecology and taxonomy are provided. In addition, an identification key for Procladius choreus and P. sagittalis based on thoracic horn characteristics is given. With our addition, the total number of chironomid species known from Romania is now 526. The study provides a baseline for future research on chironomid diversity, ecology, and biogeography in high-altitude lakes of the Carpathian Mountains.Položka Diversity and distribution of chironomids in Central European ponds(John Wiley & Sons : New York, 2024) Sedlačková Přidalová, Marcela; Hamerlík, Ladislav; Novikmec, Milan; Slobodníková, Veronika; Veselská, Marta; Bitušík, Peter; Svitok, MarekPonds are common freshwater habitats in the European landscape that substantially contribute to local and regional biodiversity. Chironomids often dominate invertebrate communities in ponds but are usually disregarded in ecological studies due to relatively complicated taxonomy and identification issues. We present a comprehensive overview of the chironomid diversity in 246 ponds spanning a wide range of conditions extending from the Pannonian Plain to the Carpathians. Altogether, we recorded 225 taxa including 192 species from six subfamilies (Podonominae, Tanypodinae, Diamesinae, Prodiamesinae, Orthocladiinae and Chironominae). However, the chironomid taxa inventory is far from complete and about 16% of the total diversity of pond-dwelling chironomids remains undetected. Chironomid alpha diversity showed a significant unimodal pattern along the elevation gradient with the highest number of taxa per pond expected around 790 m a.s.l. Gamma diversity also peaked in mid-elevations (600–800 m), and the common chironomid taxa partitioned the 2100-m long altitudinal gradient relatively evenly. The heterogeneity of chironomid communities among ponds measured as beta diversity was significantly higher in elevations below 800 m. Temperature and the proportion of surrounding forests significantly influenced alpha diversity of chironomid communities, while urban land cover and pond size had no significant effect. Ponds with a mean annual air temperature of approximately 4.8°C and a low proportion of surrounding forests are expected to harbour the most diverse chironomid communities. Our study showed that chironomids represent a very diverse and often exceptionally rich group of pond-dwelling macroinvertebrates. Given the high diversity and broad range of occupied niches, chironomids should not be overlooked in pond ecology studies. On the contrary, they should be considered a potential model group.Položka New faunistic records of chironomids and phantom midges (Diptera, Chironomidae and Chaoboridae) from Ukraine indicate recent climatic refugia in the Eastern Carpathians(Pensoft Publishers : Sofia, 2024) Bitušík, Peter; Novikmec, Milan; Svitok, Marek; Hamerlík, LadislavThe aquatic insect fauna of the Eastern Carpathians is poorly known, especially in Ukraine. To address this knowledge gap, we conducted faunistic surveys of Chironomidae and Chaoboridae in 2018 and 2021. The study involved sampling of 11 watercourses and 10 mountain lakes situated in the Ukrainian part of the Eastern Carpathians. A total of 101 taxa were identified, including 40 chironomid species and one genus that have been recorded for the first time from Ukraine. The occurrence of one species previously considered as “doubtfully present” in Ukraine was confirmed by this study. One of the two identified phantom midge species, Chaoborus (s. str.) obscuripes (van der Wulp, 1859), is recorded for the first time from Ukraine. The most intriguing records are chironomid species Cricotopus (s. str.) beckeri Hirvenoja, 1973, Eukiefferiella bedmari Vilchez-Quero & Laville, 1987, and Pseudorthocladius (s. str.) berthelemyi Moubayed, 1990. These species have Mediterranean distribution and their occurrence in the Eastern Carpathians could be remains of once-widespread populations that currently survive in the Carpathian refugia due to adverse climatic conditions in the former distribution area. The high number of first records from a relatively small number of sites indicates a great gap in the knowledge of the Ukrainian chironomid fauna.Položka Topographically shaded lakes may provide refugia for cold-adapted aquatic fauna threatened by climate change(Springer : Dordrecht, 2025) Novikmec, Milan; Bitušík, Peter; Kopáček, Jiří; Svitok, MarekUnderstanding the structure and diversity of high-altitude lake communities and the patterns of their altitudinal changes is important for predicting their response to ongoing climate change. We analysed littoral benthic communities of 18 mountain lakes of glacial origin distributed along a 500-m altitudinal gradient and characterized by differing topographic shading levels: unshaded lakes and shaded lakes with a substantially lower (by 1151 h) mean annual duration of direct solar radiation. We hypothesized that local topographic shading modifies diversity–altitude relationships and affects the pattern of community turnover along the altitudinal gradient. We found a decreasing trend in diversity with increasing altitude and a significant deviation from that pattern in shaded lakes. Investigated lake groups supported distinct communities in lower altitudes. However, their community composition converged towards higher altitudes in communities typical for a greater abundance of cold stenotherms. The proportion of cold-stenothermal species increased with increasing altitude in shaded lakes and was notably greater than that in unshaded lakes along the studied altitudinal gradient. The lower temperatures of shaded lakes and different temperature variabilities of the two groups of lakes likely explain the observed patterns. We hypothesize that topographically shaded lakes may provide refugia for cold-stenothermal communities threatened by ongoing global warming.