Monitoring Underground Disturbances (MUD): Creating a Microbial BioBank for Long-Term Monitoring of Extreme Weather Impacts on Forests

In February 2022, the UK experienced back-to-back windstorms Eunice and Franklin, which killed and uprooted trees in forests across the UK. Although these aboveground impacts of extreme weather are visually obvious and relatively easy to quantify, we know much less about how soil microbes belowground respond to the same disturbances. Yet these microbes may hold the key to forest recovery, as changes in the abundance of plant pathogens or beneficial mutualists (mycorrhizae) will influence which trees re-establish, and how quickly. We hypothesize that forest microbes are indirectly affected by storms due to physical disturbance of the soil when trees uproot, and changes in the forest microclimate under tree canopy gaps. To test this prediction, we will conduct large-scale surveys of forest condition in stands of pine, spruce, oak, and beech that were impacted by Eunice and Franklin, pairing measurements of tree falls and canopy gaps with soil sampling. Soil samples will be archived in a long-term 'BioBank' at Imperial College London, and can be analysed with DNA sequence technology to identify which species of microbes are present in each sample. The BioBank will grow over time as researchers return to the same forest sites again and again to monitor shifts in microbial communities as the forest regenerates. This will allow us to determine which types of microbes might facilitate forest recovery, and better understand which kinds of forest disturbance have the biggest belowground impacts. We will also conduct a preliminary characterization of the thousands of soil fungal species that occur across a subset of our sites, providing an immediate insight into the hidden ecosystem effects of extreme weather.