Assessment of land snail sampling efficacy in three Mediterranean habitat types

An assessment of sampling efficacy for land snails using direct searching and substratum sampling in three types of Mediterranean habitats was done at three sites in Gibraltar. The results indicate that the sites were adequately sampled after 2.5 hours of direct searching and using 4.2 litres of substratum. The applicability of the results to other sites is supported based on the analyses of diversity, species richness, number of individuals, evenness and ß diversity. The need to sample a site thoroughly by searching as many components of the habitat as possible, is illustrated using Morisita’s Index of Dispersion.