Changes in ecosystem functions following disturbances are challenged to understand the factors that affect the resilience of community structures and ecosystem functions. In many forest ecosystems, an important natural disturbance is fire. The aim of this study was to understand variations in resilience in six functional groups of invertebrates in response to different fire frequencies in southern Switzerland. We measured resilience by analysing arthropod species composition, abundance and diversity in plots where the elapsed time after single or repeated fires varied. We compared data from these plots with data from plots that had not burned within the last 30 years and defined high resilience as the rapid recovery towards the non-fire species composition.
All functional groups pooled were more resilient to single fires than to repeated events, recovering 6-14 years after a single fire, but only 17-24 years after the last of several fires. Flying predators and herbivores arthropods were the most resilient groups. Pollinators and epigaeic predators showed intermediate resilience, while decomposers and wood-eating arthropods clearly displayed the lowest resilience to fire. Their species composition 17-24 years post bum still differed markedly from that of the unburned control plots.
Depending on the fire history of a forest plot, we found significant differences in the dominance hierarchy among invertebrate species. Any attempt to imitate natural disturbances, such as fire, through forest management must take into account the recovery times of functionality and biodiversity to ensure that it is both multifunctional and sustainable.