Palaeoenvironmental changes in Central Europe (NE Poland) during the last 6200 years reconstructed from a high-resolution multi-proxy peat archive

Abstract

Peat deposits from an ombrotrophic bog (north-eastern Poland) were analysed to reconstruct peatland development and environmental changes. This paper presents reconstructions of hydrological changes and plant succession over the last 6000 years. The methods included the high-resolution analysis of plant macrofossils, pollen and testate amoebae, supported by radiocarbon dating. Three main phases were identified in the history of the bog and surrounding woodland vegetation: 4000–400 BC, 400 BC–AD 1700 and AD 1700–2011. Except for terrestrialisation and the fen-to-bog transition phase, the development of bog vegetation was mainly dependent on the climate until approximately AD 1700. The dominant taxon in Gązwa bog was Sphagnum fuscum/rubellum. Woodland development was significantly affected by human activity at several time periods. The most visible human activity, manifested by the decline of deciduous species, occurred ca. 350 BC, ca. AD 250, ca. AD 1350 and after AD 1700. These events correspond to phases of human settlement in the area. During 400–300 BC, the decline of deciduous trees, primarily Carpinus, coincided with an increase in indicators of human activity and fire frequency. At ca. AD 200, Carpinus and Tilia abundance decreased, corresponding to an increased importance of cereals ( Secale and Triticum). Since ca. AD 1350, the impact of Teutonic settlement is apparent, and after AD 1700, deciduous forests largely disappeared.

A chrysophyte-based quantitative reconstruction of winter severity from varved lake sediments in NE Poland during the past millennium and its relationship to natural climate variability

“…Most surprisingly, studies using varved lake sediments are missing despite their demonstrated potential for quantitative seasonal paleoclimate studies (Amann et al, 2014;Bonk et al, 2015;Larocque-Tobler et al, 2015). Recent work has also highlighted the potential of raised bogs as paleoenvironmental and paleoclimate archives in Poland (De Vleeschouwer et al, 2009;Gałka et al, 2014;Lamentowicz et al, 2015). …”

Do the relationships between testate amoebae and fungi reflect the variability of past water table fluctuations in the ombrotrophic peatlands of Central Europe?

“…The profiles have a thickness of 800, 835 and 600 cm, respectively. For better time control, we used absolute chronologies (Gałka et al, 2015(Gałka et al, , 2017Lamentowicz et al, 2015), refined by Kołaczek et al (2019). In the case of Gz, in which 14 C date inversions have been detected, the model with the highest agreement index and the lowest number of excluded dates was selected (Supplementary Data 1, available online).…”

“…The NPP composition was determined in the samples subjected to standard laboratory procedures including acetolysis, the same ones as those designated to palynological analysis in previous studies (Gałka et al, 2015(Gałka et al, , 2017Lamentowicz et al, 2015). As the Lycopodium tablets were added to samples (Stockmarr, 1971) and counted during both pollen and NPP investigations, it was possible to combine NPP and pollen data.…”

“…We hypothesise that the mutually exclusive extrema of HdV-31A and HdV-10 reflect dry conditions when HdV-10 increases with a simultaneous decline in HdV-31A and wet when reversed. To investigate this, we juxtaposed the newly retrieved NPP data with the already existing TA-inferred quantitative reconstructions of the DWT (Gałka et al, 2015(Gałka et al, , 2017Lamentowicz et al, 2015). As the testate amoebae are widespread in peatlands and particular taxa are linked with the specific peatland microforms (Charman et al, 2000;Tolonen et al, 1992;Warner, 1990), we combined our results considering HdV-10 and HdV-31A interrelationship with the presence of TA species identified during TA analysis (a separate analysis) to determine the in-depth characteristics of the habitat.…”

Peatland Development, Vegetation History, Climate Change and Human Activity in the Valdai Uplands (Central European Russia) during the Holocene: A Multi-Proxy Palaeoecological Study

“…Although Russia contains one of the largest areas of peatland in the world [24], there were remarkably few peat-based palaeoecological studies using proxies other than pollen [7,[25][26][27]. In particular, raised bogs in the East European Plain are affected by the continental climate conditions in contrast with better studied Atlantic or Baltic raised bogs of Northern, Western and Eastern Europe [28][29][30][31]. Past human impact on these ecosystems that cover large areas in this region [24] is also insufficiently recognized.…”