Arctic carbon under threat from climate extremes: Impacts of extreme climatic events on soil carbon and microbial communities

Extreme climatic events can have far greater impacts on ecosystems than gradual climate change. This is particularly apparent in the Arctic, where widespread damage from extreme events is causing large-scale die-back to tundra ecosystems and driving the phenomena known as "Arctic Browning". This die-back in tundra ecosystems caused by extreme climatic events is in stark contrast to the previous 30 year trend of increasing plant growth arising from gradual warming. While recent research on Arctic browning has focused on the very visible damage impacts seen above ground on plants, almost nothing is known of the impacts below ground on soil carbon and soil microbes. This is a major omission given arctic soils contain vast stores of carbon, and initial work suggests the release of this could be greatly affected by extreme climatic events, with consequences for feedback to climate.

This PhD will study the impacts of extreme climatic events on soil carbon cycling and fluxes in arctic ecosystems, with methods including measurements of soil carbon, assessment of CO2 fluxes using infra-red gas analysis, and C tracing techniques. It will also use state-of-the-art molecular ecology approaches (e.g. Illumina MiSeq, Nanopore, and associated bioinformatics) to determine changes in the biodiversity and functioning of the soil microbes that cycle carbon.