Moorland responses to weather

In this presentation, Professor Holden will discuss how upland peatlands respond to different types of weather event. The uplands of the UK are dominated by carbon rich soils and in particular they host important peatland ecosystems. Upland peatlands provide 73 % of reservoir water in the UK, are source areas of rapid runoff that can influence flood risk, store most of the UK’s terrestrial carbon and are valued landscapes for leisure and biodiversity.

Dry conditions and frost action can both loosen the surface peat ready for wind and rain to mobilise and erode the peat. The high wetness of peat means that when rainfall events occur, overland flow is dominant and river discharge rapidly increases. However, the natural properties of peat mean that during periods of little rain, the peat can still remain very wet but peat-fed rivers can almost dry up.

Human modifications to peatlands (e.g. drainage, prescribed burning, forestry, atmospheric pollution, restoration actions) can influence the way in which peatlands respond to weather events, including their susceptibility to wildfires, peatland hydrology and peat surface temperatures during winter and summer. In turn, these responses influence carbon cycling, water quality, aquatic ecosystems and flood risk. Climate change will also drive modifications to peatlands that will influence how they respond to weather events in the future. Examples of these interacting effects will be presented including discussion of management interventions that may enhance the resilience of the UK’s upland peatlands to extreme weather events.