The Late Vistulian and Holocene evolution of Jezioro Lake: a record of environmental change in southern Poland found in deposits and landforms

Maria Fajer,Mariusz Rzetala,Jan Maciej Waga,Artur Szymczyk,Robert Machowski,Marek Ruman,Małgorzata Nita,Martyna A Rzetala

doi:10.1007/s10933-012-9634-1

Abstract

Jezioro Lake is the only natural lake in southern Poland outside mountainous areas to have existed continuously since the Pleistocene. The record of environmental change in the Late Vistulian (Weichselian) and Holocene is preserved in the deposits and landforms around the lake. This paper presents the results of paleogeographical and paleoecological research that emabled us to reconstruct the history of the Jezioro Lake. At the end of the Vistulian period, the outlet of the lake was blocked by a parabolic dune moving in from the west. Limnic sedimentation was evident in the sediment core at all levels from the Holocene, with remains of Cladocera, Chironomidae larvae, and aquatic plants. The lake did not disappear at that time, although its area decreased by a factor of 12 by the end of the period. Paleobotanical research permitted the reconstruction of sequences of plant communities and changes in nutrient status and water level. An initial oligotrophic lake, as indicated by the presence of Isoetes lacustris L., changed to a eutrophic lake, as indicated by the presence of Potamogeton natans L. and Nuphar sp., then the lake progressed to the present-day dystrophic lake that is surrounded by a swamp. The profile of organic deposits contains a record of environmental change at least since the Younger Dryas in southern Poland.

Highlights

In Central and Eastern Europe, the majority of lakes that hold a record of changes in environmental conditions from the late Pleistocene until modern times in their sediments are young glacial lakes (Błaszkiewicz 2007)
Sediments that are valuable from the point of view of Late Pleistocene/Early Holocene paleogeography include those of karst lakes situated north of Lublin in Poland (Bałaga 2007, 2010) and in western Belarus, as well as ox-bow lake sediments, e.g. in the Sandomierz Basin (Nalepka 1994; Kołaczek 2010), and those of single lakes left behind by mountain glaciers (Obidowicz 1996)
A peculiar type of lake found there is the aeolian barrier lake. These lakes formed in the late Pleistocene as a result of small valleys being blocked by dunes that moved in from the west and they preserve a rich record of environmental change in their sediments

Summary

Introduction

In Central and Eastern Europe, the majority of lakes that hold a record of changes in environmental conditions from the late Pleistocene until modern times in their sediments are young glacial lakes (Błaszkiewicz 2007) Such lakes can be found from the Mecklenburg Lake District in Germany through northern Poland, Lithuania and north-western Russia to Finland. A peculiar type of lake found there is the aeolian barrier lake These lakes formed in the late Pleistocene as a result of small valleys being blocked by dunes that moved in from the west and they preserve a rich record of environmental change in their sediments. Jezioro Lake on the SilesianKrakow Upland is one of the few lakes that still remain

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