Temporal differences in snail diversity responses to wildfires and salvage logging

Abstract

Species tend to peak in abundance at different times after fires. Over time, species richness (α) and landscape heterogeneity are prone to increase and lead to greater between-site diversity (β). However, post-fire salvage logging can reduce β-diversity, both directly and through its influence on succession. The as-yet understudied response of land snails to long-term habitat modification after wildfires and forest management is important for decision-making in forest restoration and conservation. We expected to detect differences in land snails and diversity in both the short and long term and between treatments in a natural park in the Mediterranean Basin. However, our results showed that post-fire management was a non-significant variable for snail community diversity, the exception being open-habitat endemic species. Plant succession and leaf litter cover were the main variables that shaped snail diversity and abundance over time after fires. Eighteen years after a fire, the land snail diversity had improved and the community composition had diversified, irrespective of the post-fire treatment, but threatened species disappeared and the total snail numbers had notably declined. To preserve threatened open-habitat species, prescribed fires and livestock grazing are recommended in combination with mature areas that can act as shelters where forest snails can recover from future disturbances.