Effects of Olive Cultivation Characteristics on Land Snail Community Patterns in Crete, Greece

Olive agroecosystems are of great agricultural, environmental, cultural and economic importance for the Mediterranean. In the island of Crete (Greece) olive orchards are the most common cultivation, occupying 20% of the total land area. Patterns of invertebrate biodiversity of olive cultivation have been associated with farming systems, the agro-ecological zones of cultivation and landscape attributes. Terrestrial snails of 16 olive orchards under two different farming systems (organic and conventional) located in two different agro-ecological zones (plain and hilly) were studied in the Messara plain, south Crete. Linear models and Mantel tests were used to evaluate the effect of different factors on land snail richness and composition, respectively. Species richness of terrestrial snails was higher in hilly olive orchards regardless of the farming systems. Species richness was explained by landscape attributes (olive orchard area, isolation, slope and anthropogenic impact), while species composition was only partly associated with landscape characteristics. Preliminary results indicate distinct community patterns of terrestrial snails in olive orchards in the Messara plain. Landscape characteristics are important factors affecting snail biodiversity of olive orchards. Terrestrial snails are highlighted as potential indicators for studying the impact of olive orchard management on biodiversity.