Multi-proxy evidence of Holocene climate variability in Volhynia Upland (SE Poland) recorded in spring-fed fen deposits from the Komarów site

Abstract

Radiocarbon-dated spring-fed fen deposits from the Komarów site (Volhynia Upland, SE Poland) with its multi-proxy data (macrofossils, molluscs, geochemistry, pollen, stable isotopes of oxygen and carbon) enable us (1) to distinguish four main stages of fen evolution, which reflected a distinct variability of water supply conditions and (2) to reconstruct the Holocene humidity–temperature changes. The beginning of peat–tufa deposition took place in a Boreal phase, after a significant cool fluctuation of climate occurring ca. 9.4 ka cal. BP. We suggest that climate was the most important factor conditioning the development of the spring-fed fen. Permafrost degradation, and then wet periods, intensified the activity of ascending springs. The impact of humans was possible since the Neolithic period and increased during the Middle Ages: therefore, the anthropogenic influence could have partially overlapped with the regional tendencies of climate changes. Autogenic development of deposit succession in the studied fen was definitely conditioned by hydrological changes induced by climate. Based on the multi-proxy data, 12 cold events of different ranks were identified. They are also recorded in other Polish and European sites. A record of distinct variability of depositional conditions at ca. 9.4, 8.2, 5.9, 4.6, 2.8, 1.4 and 0.55 ka cal. BP corresponds to quasi-periodical global climate changes in the Holocene named the Bond events. The majority of the cold events recorded in δ13C and δ18O of carbonates can be correlated to the Greenland oxygen isotope curve.

Detrital input to spring‐fed fen deposits – a problem or an opportunity in palaeoenvironmental studies? A Holocene palaeoclimatic reconstruction from central Europe

“…A change to a cool and dry climate between ca . 7300 and 7200 cal a BP was observed also at the Komarów spring‐fed fen (Dobrowolski et al , ).…”

“…6750 cal a BP (Fig. ; Dobrowolski et al ., ). The period between 6700 and 6000 cal a BP was recognized as the driest for mires in East Poland (Żurek et al , ).…”

“…Cooling and increased humidity in north‐east Poland since ca . 4400 cal a BP were documented in Lake Linówek (Gałka et al , ) and at the Komarów spring‐fed fen in south‐east Poland (Dobrowolski et al , ). Beginning ca .…”

“…This agrees with the wet phase at the Komarów spring‐fed fen, already noted from 6200 to 6000 cal a BP (Fig. ; Dobrowolski et al ., ). Between 5900 and 4000 cal a BP, the very humid surface of the peatland south of the present shore of Lake Perty was recorded (Fig.…”

“…As a consequence, peat–tufa rhythmite forms. Shifts between subaerial and aquatic environments result in substantial changes in the conditions of CaCO 3 precipitation, which are reflected in stable carbon (δ 13 C) and oxygen (δ 18 O) isotope records of endogenic carbonates (Dobrowolski et al ., ).…”