Holocene vegetation, fire and land use dynamics at Lake Svityaz, an agriculturally marginal site in northwestern Ukraine

Abstract

Observing natural vegetation dynamics over the entire Holocene is difficult in Central Europe, due to pervasive and increasing human disturbance since the Neolithic. One strategy to minimize this limitation is to select a study site in an area that is marginal for agricultural activity. Here, we present a new sediment record from Lake Svityaz in northwestern Ukraine. We have reconstructed regional and local vegetation and fire dynamics since the Late Glacial using pollen, spores, macrofossils and charcoal. Boreal forest composed of Pinus sylvestris and Betula with continental Larix decidua and Pinus cembra established in the region around 13,450 cal bp, replacing an open, steppic landscape. The first temperate tree to expand was Ulmus at 11,800 cal bp, followed by Quercus, Fraxinus excelsior, Tilia and Corylus ca. 1,000 years later. Fire activity was highest during the Early Holocene, when summer solar insolation reached its maximum. Carpinus betulus and Fagus sylvatica established at ca. 6,000 cal bp, coinciding with the first indicators of agricultural activity in the region and a transient climatic shift to cooler and moister conditions. Human impact on the vegetation remained initially very low, only increasing during the Bronze Age, at ca. 3,400 cal bp. Large-scale forest openings and the establishment of the present-day cultural landscape occurred only during the past 500 years. The persistence of highly diverse mixed forest under absent or low anthropogenic disturbance until the Early Middle Ages corroborates the role of human impact in the impoverishment of temperate forests elsewhere in Central Europe. The preservation or reestablishment of such diverse forests may mitigate future climate change impacts, specifically by lowering fire risk under warmer and drier conditions.

Development of high diversity beech forest in the eastern Carpathians

“…Yet, because this observation is in line with general trends in the region (e.g. Dabkowski et al, 2019; Schwörer et al, 2022), and because we also have evidence of human presence with the higher occurrence of Sporormiella , we are confident that the increase in herbaceous taxa in our record represents the regional landscape opening, especially in the valleys surrounding the Vihorlat mountains.…”

A range‐wide postglacial history of Swiss stone pine based on molecular markers and palaeoecological evidence

“…8000 cal. BP (e.g., Dietre et al, 2014; Schwörer et al, 2021; Tinner & Kaltenrieder, 2005), when the climate became gradually moister due to a large‐scale reorganisation of atmospheric circulation patterns (Magny et al, 2003; Tinner & Lotter, 2006). The very dry (summer) conditions during the Early Holocene might have inhibited the widespread expansion in the Western Alps during this period.…”

“…in the southern Central Alps (Vescovi et al, 2007), its establishment in the Northern and Central Alps, and an expansion in the Carpathians and beyond. At the end of the Late Glacial, the range of P. cembra reached its largest extent, covering wide areas between the Alps and the Carpathians, and even extending northward into the Central European lowlands as documented by the inferred local presence in Western Ukraine (Figure 3a; Schwörer et al, 2021). With the rapid warming of 2-4°C in the Early Holocene (Heiri et al, 2014), P. cembra shifted to higher elevations in the Alps and reached the highest treeline positions, 200-300 m above today's treeline, during the HTM (9000-5000 cal.…”