Impacts of planned burning on the fungal diversity and vascular plants in a heathy woodland

Planned burns are an important management tool, primarily to reduce fuel loads in landscapes threatened by wildfire. Preventing fundamental changes in the composition and abundance of species within an ecosystem is also a fundamental objective of planned burns, yet the effects of planned burns (i.e. frequency, severity, season of burn and patchiness), on vascular plants and soil fungi remain poorly understood. This study uses a combination of floristic surveys and fungal DNA metabarcoding to evaluate the effects of burn frequency on the diversity of vascular plants and soil fungi in a heathland in south-eastern Australia. Our study showed planned burn frequency impacted the composition of vascular plants and vegetation post-fire successional trajectories but did not have a significant effect on belowground fungal diversity. These findings suggest that while aboveground vegetation is directly consumed by fire, the heat associated with planned burns may not be adequate to result in fungal mortality and shifts in community composition, or that effects may be relatively short-lived. Findings suggest that soil fungi in our study area, like many plants, possess adaptations to fire, which is consistent with the fire prone nature of heathlands ecosystems. Overall, this study provides a resource for understanding the impacts of planned burns on both above- and belowground biodiversity in fire prone ecosystems.