PAST LAND-ATMOSPHERE-LAKE INTERACTIONS IN BERINGIA: IMPLICATIONS FOR THE ANTHROPOCENE (Invited Presentation)

Lakes are a key landscape element in Beringia and provide local resources for human and animal populations. After a dry full-glacial period, increasing warmth and moisture led to rising water levels in lake basins, and the widespread formation and expansion of thermokarst (thaw) lakes transformed the geography of large areas. The Holocene has seen further changes in hydrology and thermokarst degradation of permafrost terrain. Lake carbon cycling other ecosystem processes have responded to changes in climate, vegetation, and rates of permafrost thaw. With current rapid arctic warming, further changes in lake properties can be expected or are already observable: the ice-free season is currently decreasing by >1 day per year; carbon processing, including CO₂ and CH₄ production, is likely to increase, and a more intense fire regime may enhance both drainage and formation of thaw lakes, depending upon topography and hydrologic conditions. Some changes in lakes are beginning to affect human activities, underlining the need to understand drivers and responses at appropriate scales across a highly heterogeneous region.