Taxonomic and functional diversity of land snails reflects habitat complexity in riparian forests.

Habitat complexity affects the structure and dynamics of ecological communities, more often with increased complexity leading to greater species diversity and abundance. Among the terrestrial invertebrate groups, the low vagility of land snails makes them susceptible to react to small-scale habitat alteration. In the current paper we aimed to assess the relationship between taxonomic and functional composition and diversity of land snail communities and habitat structure in the riparian forest habitat. We found that both snail abundance and species richness responded positively to the increase in habitat complexity. The complexity of the riparian forest affected also the snail trait composition. Forest species, species living in woody debris, leaf litter, and root zone and those feeding on detritus were more abundant in complex habitats, while large snails with more offspring, snails having the ability to survive longer periods of dryness, as well as species that prefer arid habitats, were more abundant in less complex habitats. We concluded that habitat complexity promoted functional diversity, with the amount of woody debris as main positive driver, and the adjacent agricultural fields as negative driver of functional diversity.