Fossil ostracods from lowland Lake Stiucii, Transylvania (north-western Romania)
The knowledge of past local and regional hydro-climate variability is a priority area in climate impact research as natural and anthropogenic ecosystems are entirely dependent on the local water availability. Lakes levels fluctuations (size and depth) are essential records of past climatic conditions reflecting the balance between precipitation and evaporation. The variability in a lake level may be reconstructed from changes in the abiotic (position of the sediment units and composition, chemistry) and biotic (ostracodes, diatomee, etc.) assemblages. Ostracod crustaceans are frequently abundant in lacustrine sediments and represent valuable proxy for paleoclimate and paleoenvironmental reconstructions. We aims to use the fossil ostracods as proxy to reconstruct late Holocene lake level fluctuations and productivity of a lacustrine sequence from lowlands of Transylvania, Romania. The sediment gathered from the Stiucii Lake in Romania has recorded the environmental changes linked to changes in the political landscape as well. The research is performed in collaboration with Dr. Angelica Feurdean from the Biodiversity and Climate Research Centre BiK-F, Frankfurt (Germany) (Read more at: http://www.bik-f.de/root/index.php?page_id=732) (Read more at: http://www.bbc.com/news/science-environment-33138510).
Ostracod preservation and response to Late Glacial and Early Holocene climate changes in a sub-alpine belt lake of the southern Romanian Carpathians
The role of ostracods in environmental and climate change reconstructions of Late Pleistocene and Holocene lacustrine environments of the Alpine region is well established (e.g., Loofler, 1983; Von Grafenstein, 1999; Lauterbach et al. 2011). In contrast, ostracod studies in glacial lakes of the (sub-)alpine belt of the Carpathians in Romania thus far have been completely neglected, although the effects of the last glaciation have been more significant there than elsewhere in the southern Carpathians (Reuther et al. 2007). The Retezat Mountains in the Romanian Southern Carpathians are home of several peaks of over 2000 m asl that represented the major areas of ice accumulation during the Pleistocene (Reuther et al. 2007). Due to prevailing Mediterranean circulation of moist air masses this mountain unit is the wettest (1400 mm/yr at 1500–1600 m asl) in the Southern Carpathians (Mindrescu et al. 2010). Recently, a series of Late Quaternary palaeoecological studies on the glacial lake sediments from the Carpathians has been initiated in order to provide regional palaeoclimatic and palaeoecological records inferred from multiple proxies (plant macrofossils, pollen, siliceous algae, cladocerans, chironomids as well as geochemical and ancient DNA analyses) (Magyari et al. 2009, 2011, Korponai et al. in press). The present study discusses the preservation of fossil ostracod assemblages and their response to Late Glacial and Early Holocene abrupt climate changes. The investigations were carried out on the lowermost 90 cm section of a 5 m-long core drilled in the sediments of Taul dintre Brazi Lake. This lake is located in the northern part of the Retezat Mountains at 1740 m asl in the sub-alpine belt. Due to its very small surface (about 30 m2) and clearly defined catchment area, the lake is regarded as a very sensitively and rapidly responding ecosystem. Collaborator within the project PROLONG of Eniko Magyari, Hungarian Academy of Sciences, Budapest (See more at: https://sites.google.com/site/enikomagyaripollen/cv/prolong).