Holocene climate vs. catchment forcing on a shallow, eutrophic lake in eastern Poland

Abstract

This paper presents a sedimentary record from Lake Łukie located in the southeastern part of the Central European Plain, beyond the reach of the maximum extent of the last glaciation. The lake has thermokarstic origin and developed during the last glacial termination due to subsidence of the sub‐Quaternary carbonate basement triggered by permafrost thawing. A sediment core was investigated to reconstruct water trophic state and lake depth changes during the Holocene. We aimed at showing the relationship between ecological and geochemical changes in the lake and regional/supraregional climatic and hydrological trends throughout the Holocene. Results of subfossil Cladocera analysis were combined with data on the geochemistry and stable C and O isotopes in sedimentary carbonates. Isotopic and geochemical proxies helped to detect sources of sedimentary particles in the lake and thus to reconstruct changes in the intensity of atmospheric and catchment processes (e.g. precipitation and surface runoff). The Cladocera analysis results indicated endogenic processes in the lake such as trophic changes. Our data revealed that Lake Łukie has always been a rather eutrophic water body and the periods of particularly high productivity were in the lower Preboreal and upper Subatlantic. Periods of increased water depth were recorded in the lower Preboreal, lower Boreal and upper Subboreal, whereas low water stands were obtained during the late Preboreal, late Boreal, late Atlantic and Atlantic/Subboreal transition as well as during the lower Subboreal. The sediment succession from Lake Łukie provides the first full Holocene record of carbon and oxygen stable isotopes in lacustrine carbonates from the eastern part of the Central European Lowland. The record is characterized by uncommonly high δ13C and δ18O values of the carbonates resulting from a combination of within‐lake processes and dissolution of the carbonate bedrock of Cretaceous age. The impact of the old carbonates on isotope values was helpful in the reconstruction of the catchment forcing on the lake.

Geochemical Approach to the Reconstruction of Sedimentation Processes in Kamyshovoye Lake (SE Baltic, Russia) during the Late Glacial and Holocene

“…The maximum values of the organic matter content (50-60%) are marked in the upper part of the column 315-265 cm (1650-1300 cal y BP). The maximum values of organic matter during the Subatlantic period are also marked in the region [35].…”

The environmental context of Early Neolithic cultural transformation in the Targowisko settlement region

“…The Cladocera species identified at a depth of 240 cm are typically linked to the aquatic vegetation Alonella excisa, Alonella exigua and Alona guttata (Flössner 2000); no species characteristic of an open water zone has been recorded in that layer. The reservoir, therefore, must have been very shallow and overgrown with aquatic plants at that time (Duigan 1992;Zawiska et al 2019). In the pollen spectra of that section (242 cm), single grains of Sparganium, Comarum palustre and algae from the Chlorophyta group (Pediastrum) appeared.…”

Wioślarki

“…Wioślarki uważane są za organizmy wrażliwe na zmianę trofii i dlatego są wykorzystywane do rekonstrukcji zmian żyzności jezior (Whiteside 1970;Szeroczyńska 1991;Zawiska 2019;2020). Jednakże uważa się, że trofia wody wpływa na wioślarki pośrednio, kiedy zmienia ich warunki życia, m.in.…”

“…Kolejny prezentowany diagram tak właśnie został zrobiony (ryc. 6), a czas określony został poprzez wydzielenie okresów Holocenu za pomocą analizy pyłkowej (Zawiska i in. 2019).…”