Soil seed bank responses to coppice management in a Mediterranean oak forest

The soil seed bank is a key component for forest dynamic processes, but the impact of management in Mediterranean woodlands is still poorly known. We investigated the effects of coppicing in a thermophilous oak forest in Italy. Seed germination from soil cores collected in young coppice (CWS) and long abandoned (UF) stands was monitored for eight months to determine seed density, species diversity, composition and ecological characteristics (i.e. life-forms, forest guilds and Ellenberg indicator values) of the soil seed bank community. Overall, a higher number of seedlings emerged from the CWS soil, and seed density was positively affected by light. Species richness increased with soil pH, higher in CWS. Species composition significantly diverged between the two stand types. In CWS, annual generalists of open habitats and non-native invasive weeds were dominant over forest specialist species. Contrastingly, these were more represented in UF, though light-demanding and earlysuccessional species persisted in the soil as a legacy of former disturbances. Soil seed bank communities in CWS were more similar to extant understorey vegetation than in UF (Bay-Curtis similarity 0.078, 0.017 respectively), where abandonment led to stronger floristic divergence due to habitat filtering. Coppicing increased richness and heterogeneity of the soil seed bank, providing a pathway for colonization by ruderal species and invasive weeds. Management measures that limit the input of ruderal and invasive species, maintain higher canopy cover, and reduce post-harvest soil disturbance, will help preserve the native diversity and functional integrity of the soil seed bank in Mediterranean oak forests.