The paleolimnological analysis of sediments from high mountain lake Nižné Terianske pleso in the High Tatras (Slovakia)

Sedimentological climate proxies and a 200-year long climate record, reconstructed using a data-set of European-wide meteorological data, have been compared at the high mountain lake Niné Terianske pleso in the High Tatras, Slovakia. Diatoms, chrysophyte stomatocysts, chironomids, plant pigments and spheroidal carbonaceous particles (SCPs) were analysed as well as sediment lithostratigraphic parameters. Using a radiometric approach the sediment core was dated and a depth of 4.6 cm was found to correspond to 1852 AD. The sediment accumulation rate (0.0034 g·cm^–2·yr^–1) was one of the lowest identified in the European mountain lake project, MOLAR. Despite this slow accumulation rate a remarkably coherent lithological and stratigraphic record has been recovered. The sediments of this remote mountain site, largely free from the effects of direct human impact, have been found to display a wealth of variability over the last 200 years.The record of spheroidal carbonaceous particles, indicators of anthropogenic pollution deposition, begins around 4.5–5.0 cm in depth (1833–1857). Temporal patterns are typical of European lake sites with the concentration peaking in the late 1970's. The SCP/²¹⁰Pb inventory ratio for the site is also in good agreement with the European latitudinal pattern. A strong influence of sample age on the chrysophyte assemblage composition in the upper-most 4–6 cm indicates that the main changes in the cysts have been related to long term environmental changes, probably pH. Analysis of chironomid remains revealed a stable profundal community. Chironomids as a whole showed no correlations to temperature fluctuations in the last 200 years. Relatively abundant remains of Diamesa sp. head capsules and other taxa closely associated with stream conditions in the older layers contrast with the absence of Diamesa sp. in the recent sediments. This change is considered to be evidence for the existence of a stronger, more stable inlet supplied from permanent granular snow fields in the lake basin. The most important changes in diatom assemblages were observed at 3cm. Many species of the genus Achnanthes spp. together with Navicula schmassmannii and Orthoseira roeseana made up the greatest part of the diatom community above 3 cm, being absent or rare lower in the record. A positive correlation between diatoms and mean summer temperature was found.     

Stoneflies (Plecoptera) in some volcanic mountain ranges of the West Carpathians (Slovakia) and the impact of human activities

44 stonefly species were recorded in the Pol'ana mountains (Central Slovakia). A typical representative of the west-east fauna, Rhabdiopteryx navicula, was found. The Hučava stream basin represents the southern border of the montane and submontane distribution of stonefly species, which are bound to the river basins in high and central mountain regions of the West Carpathians. Six characteristic associations of stoneflies were recorded. Shredders predominated in the upper, and scrapers and collectors in the lower section of the Hučava stream. Detritivores were more abundant in the gravel-to-sandy mesohabitat, whereas predators and scrapers prevailed in rocky mesohabitat. Total annual production was low — 340.4 g · m⁻² (dry weight), though being three-times higher in the rocky mesohabitat than in the gravel-to-sandy mesohabitat. The annual P/B ratio of stoneflies reached 3.3. Clear-cutting and operation of small hydropower stations were found to have a significant impact on the taxocoenoses of stoneflies.