Ideas and perspectives: the biogeochemical role of taliks

Abstract. Taliks, unfrozen ground within permafrost, sustain year-round biogeochemical processes, mobilizing carbon, nutrients, and contaminants through lateral and open taliks, while closed and isolated taliks confine reactions locally. Yet, while talik physical and thermal dynamics have been increasingly documented, their biogeochemical processes remain understudied, particularly in winter.  In this manuscript, we argue that taliks represent a critical and overlooked driver of Arctic and sub-Arctic biogeochemical processes. We put forward three testable hypotheses to advance the study of talik biogeochemical functioning and we propose a related road map: year-round sampling, standardized protocols, pan-Arctic talik mapping, and community-building.