Transformation of Lake Ecosystem into Peat Bog and Vegetation History Based on Durne Bagno Mire (Lublin Polesie, E Poland)

Abstract

Abstract:In this paper, the history of Durne Bagno, i.e. the largest peat bog in the Lublin Polesie, is shown. Peat bogs are a unique element of the Polesie landscape. They occur mostly in the subregion of the Łęczna-Włodawa Lake District occupying 1.07% of its area. They fill basin-shaped depressions without outflow, often in the immediate vicinity of dystrophic lakes. Based on interdisciplinary research, the changes of vegetation cover and the Durne Bagno lake-mire ecosystem in the Late Glacial and Holocene are presented. The environmental conditions are reconstructed from pollen analysis, detailed identification of algae of Pediastrum genus and chemical composition of deposits, together with the results of Cladocera analysis. The distribution of archaeological artefacts in the surroundings of Durne Bagno peat bog gives the view on the intensity of settlement in this area. The duration of the limnic and mire stages during the development of the ecosystem was different in different parts of the examined depression. In its central part the limnic stage lasted about 8000 years and included the period from the Late Glacial to the middle Holocene (to about 6000 BP). It is represented by 7 pollen zones and 6 chemical zones. The mire stage contained a part the Atlantic period and on the Subboreal and Subatlantic periods. It is represented by 4 pollen zones and 5 chemical zones. Limnic and mire deposits differ widely in the concentrations of chemical elements. The contents of mineral material and almost all analyzed elements in limnic deposits are high. These deposits are characterized by positive correlation between the contents of Zn and Cr and the frequency of Cladocera fauna. Peat contains very low amount of mineral material. The contents of Ca, Sr and Ba are rather high in sedgemoss peat. The concentrations of these elements decrease upwards due to oligotrophic processes and sedentation of sedge-Eriophorum-Sphagnum peat. Peat succession was modified by pastoral economy of prehistoric man.

Changes in the Natural Environment Recorded in the Sediments of the Karaśne Lake-Mire Complex (Lublin Polesie, E Poland)

“…It should be emphasized that the curves of these bioelements correspond with Cr, Zn and Pb curves (depth 425 cm). The synchronous character of the frequencies of Zr, Cr, and Cladocera is observed also in the Durne Bagno site (Bałaga, 2007).…”

“…The diagram Ka-C shows that the introduction of hornbeam -a new component of the forests -into the surroundings of the examined site was relatively slow, comparable to that of the Durne Bagno site (Bałaga et al, 2006 and2007). From the profile Ka-C, which reflects the local conditions, it can be deduced that the maximum proportion of hornbeam in forests occurred from 3500-2700 BP.…”

“…Therefore, the occurrence of hiatuses cannot be excluded, especially at the sharp contacts of different deposits. The problem of disturbances during the initial phase of the development of lakes is discussed at length in the monograph on the Durne Bagno peat bog (Bałaga, 2007). To sum up, the deposits of the SalixCyperaceae zone in the Karaśne site, as those in the Perespilno profile, can be related to the end of Pleistocene, and point to a similar period of the Lake Karaśne formation.…”

Hydrochemical and microbiological distinction and function of ombrotrophic peatland lagg as ecotone betweenSphagnumpeatland and forest catchment (Poleski National Park, eastern Poland)

“…It occupies the clearly distinguishable oval-shaped depression in sandy deposits. The western part of the depression is rather shallow and its eastern part reaches the depth of 7-8.5 m (Bałaga, 2007). The monthly average air temperatures of January and July are x4.1 and 17.9 xC, respectively, and the average annual total rainfall is 551 mm.…”

Multi-proxy reconstruction of mire development in the Poręby Wojsławskie ecosystem (Sandomierz Basin, southeastern Poland)

“…Dobrowolski et al, 2001;Bałaga, 2004Bałaga, , 2007aBałaga, , 2007bChambers and Charman, 2004;Ross-Barraclough et al, 2004). The use of multiple proxies for reconstruction of changes in hydrological and climate conditions is a commonly practised method in lake and peatland environment research (Digerfeldt, 1988;Willis et al, 1995;Issmer, 2009;Dobrowolski et al, 2010;Lamentowicz et al, 2011).…”