Wildfire size, severity and timing vary with dominant vegetation in open landscapes in England and Wales

Wildfires are an increasing concern worldwide, as climate change extends periods with the necessary conditions for fires to spread. This study focuses on wildfires in England and Wales, as the fire regimes of these countries are just beginning to be understood and policy to mitigate wildfires is based on limited evidence. We used satellite data to build a 3‐year spatial database of 206 wildfires, and analysed this to determine patterns in fire size, severity and timing. This is the largest and most comprehensive dataset of fires across these countries using Sentinel‐2 data, allowing us to detect previously unrecognised patterns in fire severity. We also collected field data across five wildfires in England, supplemented with previously published data. This field dataset validates the use of the dNBR (differenced Normalised Burn Ratio) as a measure of burn severity, which has not previously been analysed for UK landscapes. We found that wildfires in Molinia ‐dominated areas are larger and occur earlier in the year, whilst those in landscapes dominated by scrub or shrub type vegetation communities are smaller but more severe. Molinia is spreading in some areas of the UK, which makes it important to recognise the unique characteristics of its fire regime. Our results demonstrated that areas with higher percentages of heather ( Calluna vulgaris ) are positively correlated with higher fire severities, whilst areas of mixed heather and Molinia have fires which are both large and severe. Areas of heathland, with higher percentages of bracken, gorse, or small trees, burn later in the year and have small, severe fires. Alongside vegetation, we considered land management and found evidence to support creating firebreaks to reduce fire size. We suggest that these results should be used to plan fire management specific to different vegetation types across England and Wales. Practical implication. Our work uses both field and satellite data from wildfires across England and Wales to demonstrate that wildfire size, severity and timings are significantly different across differing vegetation communities. Our results contribute to international understandings of wildfire regimes and the use of satellite data for assessing fire severities.