NATURAL COMMUNITY TYPES AND NATIVE AND NON-NATIVE TERRESTRIAL GASTROPODS IN THE PIEDMONT REGION OF GEORGIA

Terrestrial gastropods impact ecosystem function through calcium cycling, decomposition, and more. They can serve as important indicators of environmental health as affected by urbanization, pollution, non-native taxa, and additional factors. Research on land snails and slugs in Georgia is limited, and mostly focused on species distribution at larger geographic scales. This study aims to examine these faunal assemblages of land snails and slugs as they correspond to different natural community types in the Piedmont around metro-Atlanta. This physiographic region is characterized by rolling hills underlain by igneous and metamorphic rocks such as granite, gneiss, schist, and saprolite. Natural community types are formed as a product of weathered rock that determines soil composition, moisture, depth, and contribute to slope-direction/angle. Most rocks in the Piedmont are felsic and weather to more acidic soils, while the fewer mafic rocks weather to more fertile soils. Three of the seven natural community types in the Piedmont were the focus of this research: Mesic Forests, Oak-Pine-Hickory Forests, and Pine-Oak Woodlands. Twelve localities were selected for study with fieldwork consisting of site visits to search for snails and slugs in moist, shaded areas primarily by turning over logs or other detritus. Observations are all geo-referenced, recorded, and identified through the iNaturalist application, and additional data from public observations in iNaturalist were also utilized in this research. To date ~270 observations were examined revealing the presence of 22 genera and at least 28 species in these communities. Of 22 genera, 14 are native, 12 are non-native, and one genus has both native and non-native species. Variations in the distribution of non-native taxa are significant as these taxa may serve as predators or competitors to native biota. Proportions of native to non-native taxa are thus far similar in all community types with greater percentages of native taxa relative to non-native taxa. However, non-native taxa appear to be more likely found at certain localities requiring further investigation. Data collection is ongoing; more research is needed to determine the extent to which snail/slug assemblages reflect natural community types and the influence of human impacts at these localities.