Guide to diatoms in mountain lakes in the Retezat Mountains, South Carpathians, Romania

Abstract

Abstract:Mountain lakes have special importance in the neo-and palaeolimnology. Th e diatom fl ora of mountain regions of Europe has been studied in detail, but less attention was paid to the Romanian part of the Carpathians. Siliceous algae of mountain lakes (1,740-2,122 m a.s.l.) were studied in the Retezat Mts (South Carpathians, Romania). Sediment samples were collected in the deepest points of twenty-three pristine lakes between 2011 and 2014. A total of 152 species and intraspecifi c diatom taxa were found during this study (excluding the representatives of the two most diverse diatom genera Eunotia and Pinnularia). Altogether 140 taxa were listed and nomenclaturally checked from the previously published results. 79 common species and some rarely reported taxa are illustrated by means of light-(LM) and scanning electron microscope (SEM), and 40 other are presented here only with LM images. A partial diatom checklist is presented with 217 items, 80 of them have been recently recorded for the Retezat Mountains. Th is compilation focuses on small celled (< 20 μm) diatoms. Th e main aim is to help the identifi cation to the hardly visible, lightly silicifi cied and recently described forms, instead of repeating the earlier published data. Th is guide consist of a detailed light and scanning electron microscopy documentation of the diatom fl ora, based on 752 LM and 188 SEM pictures. New Humidophila and Staurosira taxa are presented and a new combination is proposed for Achnanthes helvetica var. minor. Th e detailed, illustrated guide hopefully will be a useful manual for ecological and palaeoecological surveys in the future.

First record of Gomphonema lacunicola Patrick et Freese (Bacillariophyta) from the Pâreng Mts (Southern Carpathians, Romania)

“…To gain a clearer picture of species variability of rare species our aim was to document the occurrence of a rare Gomphonema species from the Southern Carpathians. Th ese results contribute with new data to earlier published data and to the study conducted in the region (Buczkó 2016, Buczkó et al, 2018a, 2021.…”

“…In the last couple of years, intensive taxonomic work has been carried out in the Botanical Department of the Hungarian Natural History Museum in order to explore the diatom fl ora of mountain lakes in the Carpathian Mts (Buczkó 2016, Buczkó and Magyari 2007, Buczkó et al 2018a, b, 2021. Th ese studies have two main directions (1) a palaeolimnological survey covering the Last Studia bot.…”

Surface sediment diatom assemblages from four alpine lakes in the Zelengora Mountains (Bosnia and Herzegovina): A pilot study

“…The greatest resemblance in terms of phisical properties (i.e. lake surface and depth) was found with the alpine lakes in the Retezat Mountains (southern Carpathians), while the similarity with the Zelengora lakes, in terms of diatom flora, refers to the presence of mainly small benthic Staurosira taxa (Buczkó 2016). The presence of Staurosirella neopinnata and Staurosira construens has also been confirmed in the Shara and Nidze Mountains (Levkov et al 2005), the Pyrenees (Rivera-Rondón & Catalan 2017), the Tatra Mountains (Štefková 2006), the Rila Mountains (Ognjanova-Rumenova et al 2011) and the Pirin Mountains (Stefanova et al 2003).…”

“…Furthermore, Levkov et al (2005) and Rivera-Rondón & Catalan (2017) also reported the presence of Gomphonema pumilum, which is consistent with its dominant presence in the Orlovačko Lake. In addition, Buczkó (2016) reported Gomphonema taxa to be the fourth most common species in the Retezat Mountain lakes. One of the most common taxa in the Zelengora lakes was Achnanthidium minutisimum, which has also been reported in previous research of diatom floras from alpine oligotrophic lakes accross Europe (Levkov et al 2005;Štefková 2006;Buczkó 2016;Rivera-Rondón & Catalan 2017;Ognjanova-Rumenova et al 2019).…”

“…Studies of the regional diatom flora are scarce; to date only one study of the diatom flora of alpine lakes in Bosnia & Herzegovina has been published (Hafner & Jasprica 2013). On the other hand, numerous studies of diatom floras in European alpine lakes have been conducted in recent years (Levkov et al 2005;Štefková 2006;Buczkó 2016;Feret et al 2017;Rivera-Rondón & Catalan 2017;Rott & Kofler 2019;Tsarenko et al 2021). In order to establish biomonitoring programmes, the first step is to provide detailed ecological information about diatom assemblage compositions within a range of lacustrine settings.…”