Limited spatial co-occurrence of wildfire and prescribed burning on moorlands in Scotland.

Abstract

Prescribed burning of vegetation is a land management approach that can be used to prevent or reduce the risk of wildfires yet burns can escape and be an ignition source for wildfires. In Scotland, muirburn is a form of prescribed burning used to encourage new growth of heather for grouse and livestock. Future regulation aims to mitigate potential negative impacts of muirburn on biodiversity, peat carbon stocks and wildfire risk. In this study, we assessed the spatial co-occurrence of muirburn and wildfires across Scotland. Evidence of muirburn was quantified using high-resolution aerial imagery from 2018 and wildfire occurrence was a composite of satellite and aerial detection covering 2015 to 2020. Fires were mapped on to dominant vegetation habitat types (acid grasslands, heather grasslands, heather heathlands, and peatbogs) and peat soil. Overall, 96 % of the total wildfire area occurred outside moorlands managed by muirburn, with wildfires covering 1.1 % of total moorland area. Heather grasslands, peatbogs and habitats on peat soils had a greater proportional area of wildfires than other moorland habitats and habitats on non-peat soils. In contrast, heather heathlands with non-peat soils had a greater proportional area of muirburn. We suggest the limited co-occurrence of muirburn and wildfires, may be due to fuel load reduction following muirburns, but may arise due to wildfire prevention strategies on estates and/or lower occurrence of recreational caused wildfires. In addition to muirburn regulation, our findings emphasise the need for policy, management, awareness and education outside of muirburn areas to reduce the risk of wildfires.