Pond sediment microbiome of a glaciated high-latitude wetland

High-latitude, coastal wetland biogeochemistry is particularly dynamic in response to climate change, and yet we do not understand, and thus cannot fully predict, how crucial aspects of these systems will change in the future. Temperatures in the Northern Hemisphere have disproportionately increased 4C in 30 years causing the rate of deglaciation to increase significantly in global high-latitude river deltas. This will have a prolonged effect on local microbiome metabolism and biodiversity of the subsurface, influencing solid, liquid, and gaseous compounds in the system. We hypothesized that outwash pond sediment biogeochemistry would reflect a glacier-to-ocean axis given significant ablation and subsequent deposition of freshwater and nutrients into the downstream ecosystem. Our findings support this hypothesis and suggest complicated yet significant interactions between iron species, carbon cycling, and microbiome composition. By using the Copper River Delta in south central Alaska as a model high-latitude wetland, we identified how hydraulic regimes may be capable of shaping a complex and glaciated wetland landscape.