The Holocene hydroclimatic changes, palsa peatland development and vegetation history in the inner part of the Central Siberian Plateau (Russia)

The permafrost peatlands of Central Siberia are crucial carbon sinks that are vulnerable to climate warming. However, their Holocene dynamics remain poorly understood. This study presents a high-resolution, multiproxy reconstruction of hydroclimatic changes, peatland development and the history of vegetation from the Gornoye palsa peatland in the Inner Central Siberian Plateau. By analyzing plant macrofossils, pollen, testate amoebae, stable isotopes (δ¹³, δ¹⁵N) and radiocarbon dating, we have traced peatland evolution over the Holocene. Our results revealed a non-linear development characterized by complex feedbacks between regional climate and local conditions. Paludification of a wet larch forest began ∼8700 cal yr BP, evolving into a rich fen during the Holocene Thermal Maximum (7800–5300 cal yr BP). The first permafrost aggradation occurred ∼5500–5000 cal yr BP. The Mid-Late Holocene time interval (5380–600 cal yr BP) was marked by cyclical oscillations between permafrost uplift (peat plateau stages) and degradation (fen conditions), driven by climate fluctuations. A major phase of sustained palsa growth commenced after 2250 cal yr BP, reflecting Neoglacial cooling. An abrupt shift to a waterlogged thaw hollow ∼600 cal yr BP signifies a major collapse of the perennial frost mound. We conclude that the peatland's evolution is highly sensitive to hydroclimatic changes, with its carbon and nitrogen cycles directly impacted by freeze-thaw dynamics. The current mosaic of stable and degrading peat plateaus suggests that the system is responding to modern warming. This study provides a benchmark for understanding the long-term vulnerability of Siberian peatland carbon stocks to climate change.