Recovery of temporary pond alpha and beta diversity after wildfire disturbance: the role of dispersal and recolonization processes

Wildfires are a global disturbance being enhanced by human-induced pressures. Their frequency and intensity are expected to increase in the near future in regions such as the Mediterranean Basin. While responses of terrestrial systems to wildfire have been thoroughly studied, aquatic systems such as temporary ponds have received less attention. Furthermore, previous works have focused on wildfire impacts in aquatic systems from a functional and trait-based approach, but such disturbances can also impact the diversity of these systems at the local and regional level. In this work, we assessed wildfire impacts on alpha and beta diversity of Mediterranean temporary ponds by analysing samples of pond macrofauna after a wildfire burned part of a cluster of these habitats. The wildfire did not change alpha diversity patterns, but differences in beta diversity were observed when considering species abundance. Species with greater contribution to beta diversity were more strongly represented in unburned ponds after the wildfire. These changes occurred mostly during the beginning of the hydroperiod, which increased regional differences in burned ponds, but decreased toward the middle and the end of the hydroperiod. Overall, we report a fast recovery of communities after the wildfire, tightly linked to a rapid recolonization that increased similarity. Landscape structure and seasonal succession are key to the recovery of these systems. However, this recovery capacity might be compromised in the future by increasing occurrence of wildfire and the potential for substantial habitat loss.