Post-fire management and forest type affect species diversity, composition and resprouting during early recovery stages in a Mediterranean vegetation area

The risk of wildfires in the Mediterranean region is expected to increase with climate change. Fire is one of the main driver of plant diversity and composition, as it triggers succession processes that vary according to the fire characteristics and species regeneration traits. Human management modulates these processes through the application of practices such as salvage logging, to promote the recovery of the burned soil vegetation system. Effects of these practices have been studied mostly for coniferous forests, with contrasting results, while little is known about the responses of evergreen broadleaved vegetation in terms of diversity, composition and plant fire-related traits. In this work, we analysed the three-years response of a Mediterranean maquis and a pine stand in central Italy, destroyed by fire in 2017. Three management practices were applied after fire: 1) no intervention (NT), 2) salvage logging + mulching (SM and SMP for the pine stand), 3): salvage logging + mulching + erosion control (e.g. fascines for hill slope stabilization; EC). Overall, the increase of post-fire vegetation cover was negatively affected by both SM and EC treatments, while their effects on ɣ- and α-diversity were positive. Species diversity was significantly lower in pine than in maquis plots, and compositional differences were significant. Abundance of woody species was higher in the unsalvaged sites, excepted for a few species (e.g. Quercus ilex L.), while the other plant growth forms were not affected by management practices. Species composition in EC plots was different from the other plots in the first and second year, while it tended to converge three years after fire. Effects of management practices on the frequency of resprouters were minor, as well as on the proportion of species with persistent vs. transient soil seed bank on; such traits were mainly driven by forest type. Our findings support that non-treatment is the best post-fire management for a fast recovery of woody species in the typical Mediterranean broadleaved sclerophyllous maquis. However, the combination of salvage logging with soil erosion control practices has no negative impacts on diversity and reduce species composition changes, allowing to combine biomass recovery with a higher ecological sustainability.