Land snail diversity can reflect degrees of anthropogenic disturbance

Abstract

Faunal indicators of old‐growth forests in heavily‐disturbed regions are virtually non‐existent. However, land snails, in particular micro‐snails, could reflect the impact of land‐use on ecosystem integrity. Because of their size, limited mobility, and propensity to spend their entire lives at one locality due to lack of migratory behavior, micro‐snails are susceptible to changes in land‐use within forested ecosystems. Therefore, we proposed the hypothesis that micro‐snails would reflect land‐use in forested ecosystems. We sampled snail communities in paired old‐growth and second‐growth forests in three distinct ecoregions. Species diversity, richness, and abundance were greater in two of the three old‐growth sites compared to paired second‐growth sites. Across all of the ecoregions, 21 out of 70 species had an affinity for old‐growth. Eighteen of which were statistically significant. These results suggest that anthropogenic disturbance plays a key role in shaping species diversity and community structure of land snail fauna. However, site specific factors also appear to be important moderators of the response, and the mechanisms of the process remain to be studied. Snails appear to be a promising group of organisms to use as indicators of historic forest disturbance. In order to maintain ecological integrity, forest managers should consider management strategies that are low impact and protect existing patches of old‐growth forests.