Burning histories derived from charcoal preserved in sediment archives offer scope to reconstruct past climate and landscape dynamics. The fault-bounded Aksay Pond in northwestern China preserves an 80-year sediment sequence spanning 1931 to 2012 that reveals undetected punctuated fire events within the last ca. 1000 years. We used Bayesian inferential modelling of 24 macrocharcoals that have been directly 14C Accelerated Mass Spectrometry dated to examine past phases of fire activity and compare these phases with other fire-proxy records from the Altai Ranges. That these charcoals formed, were stored in the landscape and subsequently mobilised into the pond suggests that fires occurred at these different times. This method for examining fire histories differs from more traditional techniques and has some inherent uncertainties that are discussed. Importantly, our charcoal record does not attempt to infer severity, intensity or number of fires but identifies undetected periods of burning. Charcoal was dated to three statistically distinct phases spanning 95% highest posterior density ranges of 1170 to 1290 CE (Phase 3), 1410 to 1650 CE (Phase 2) and 1720 to 1900 CE (Phase 1) with some post-1950 CE charcoal. Bayesian modelling also demonstrates that Phase 3 does not coincide with burning histories from elsewhere in the Altai Ranges suggesting localised fires during the early to middle stages of the Medieval Climate Anomaly. Phase 2 charcoals overlap with a significant period of burning from the western Altai Range during the early stages of the Little Ice Age (LIA) indicating a larger regional environment primed for fire. Phase 3 charcoals from Aksay Pond occurs during the transition from peak LIA to Recent Warming and likely reflects regional increases in anthropogenic burning. Our Bayesian analysis of the burning periods from the Aksay Pond with other fire records from the Altai Ranges demonstrates that burning in the region is spatio-temporally heterogeneous and that further sites need investigating to capture the true history of burning from the region. Our novel approach also demonstrates the utility of short-lived sedimentary archives as alternative proxy sources for long-term fire histories in data-scarce regions.
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