The Impacts of Heather and Grassland Burning in the Uplands: Creating Sustainable Strategies

Both nationally and globally, UK upland peat is an important store of carbonas well as a source of other important ecosystem services. However,concerns have been raised regarding the stability of these stores.Significant increases in water colour and dissolved organic carbon (DOC)from catchments draining upland peat have been observed across the UK.Unlike many boreal peats, the peat soils of UK uplands are heavily managedfor sheep grazing and recreational shooting. Productivity of theselandscapes has been increased through managed burning of the vegetation.Burning has been linked with increases in water colour and inappropriateburning can lead to ‘unfavourable’ conditions in these landscapes.This thesis presents the results from a monitoring programme at MoorHouse National Nature Reserve. Results show that burning does not lead todramatic increases in DOC and that longer rotations may have benefits forcarbon by reducing water colour. Increases in the occurrence and changesin the quality of runoff water following burning could help explain changes inwater quality parameters such as DOC.Experimental studies into biomass loss during burning, combined with asurvey of a wildfire, have shown that the production of char is an importantcarbon store that should be accounted for in fire prone upland settings.Modelling studies suggest that rotation lengths of 15 years are suitable forchar production and that on these longer rotations char becomes a moreimportant carbon store than any remaining unburnt biomass or litter.Therefore this work would suggest that longer rotations may have benefitsfor carbon storage and water quality. Longer rotations may be sustainable insome areas but that this is unlikely to be appropriate across the entire of theUK. The caveats to this work should always be presented and localknowledge be consulted when drawing up management plans.