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 carbon as 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 managed for sheep grazing and recreational shooting. Productivity of these landscapes has been increased through managed burning of the vegetation. Burning has been linked with increases in water colour and inappropriate burning can lead to ‘unfavourable’ conditions in these landscapes. This thesis presents the results from a monitoring programme at Moor House National Nature Reserve. Results show that burning does not lead to dramatic increases in DOC and that longer rotations may have benefits for carbon by reducing water colour. Increases in the occurrence and changes in the quality of runoff water following burning could help explain changes in water quality parameters such as DOC. Experimental studies into biomass loss during burning, combined with a survey of a wildfire, have shown that the production of char is an important carbon store that should be accounted for in fire prone upland settings. Modelling studies suggest that rotation lengths of 15 years are suitable for char production and that on these longer rotations char becomes a more important carbon store than any remaining unburnt biomass or litter. Therefore this work would suggest that longer rotations may have benefits for carbon storage and water quality. Longer rotations may be sustainable in some areas but that this is unlikely to be appropriate across the entire of the UK. The caveats to this work should always be presented and local knowledge be consulted when drawing up management plans.