Assessment of terrestrial snails’ diversity and composition in six forests of west central - Morocco along an altitudinal gradient

This study aims to investigate the diversity of terrestrial gastropods in west-central Morocco. It also examines how elevation and other abiotic factors affect the distribution and composition patterns of said malacofauna. The sampling covered six different forest sites with thirty stations spanning on an altitudinal gradient that ranges from 24 to 2434m. The influence of abiotic factors on species richness and abundance was evaluated via the Pearson correlation. The Shannon index evaluated the malacofaunal diversity within each station. Whittaker’s index assessed heterogeneity of each forest site. The similarity between the forest sites was determined by multivariate analyses; namely the Jaccard index and the Nonmetric Multi-Dimentional Scaling analysis (NMDS). A total of 31312 specimens representing 30 species were recorded. Low altitude stations display the highest values of diversity and uniformity, while the highest altitude stations present the opposite trend. The NMDS analysis revealed that the elevation and vegetation type represent the principal factors affecting the distribution of land snails in the six forest sites.