Our study provides a new comprehensive assessment of the limnological state of 66 lakes in the Central Yakutian alaas landscapes and the Verkhoyansk mountain range. Our analyses suggest that specific lake-type properties within the thermokarst lake sequence seem to drive inorganic, organic, and isotopic lake hydrochemistry. Future warming may lead to less diversification within lake macrophyte assemblages in old alaas lakes.

Despite rapidly intensifying wildfire seasons in Siberian boreal forests, little is known about long-term relationships between changes in vegetation and shifts in wildfire activity. Using lake sediment proxies, we reconstruct such environmental changes over the past 10,800 years in Central Yakutia. We find that a more open forest may facilitate increased amounts of vegetation burning. The present-day dense larch forest might yet be mediating the current climate-driven wildfire intensification.

Data about past fire activity are very sparse in Siberia. This study presents a first high-resolution record of charcoal particles from lake sediments in boreal eastern Siberia. It indicates that current levels of charcoal accumulation are not unprecedented. While a recent increase in reconstructed fire frequency coincides with rising temperatures and increasing human activity, vegetation composition does not seem to be a major driver behind changes in the fire regime in the past two millennia.