Climate gradients, and patterns of biodiversity and biotic homogenization in urban residential yards

Supporting information S1 Fig. Percent contribution of each sample type to the total abundance in each of the 12 surveyed towns. Towns are shown in their relative N-S and E-W orientations. ‘Shells’ included both macro- and micro- snails—and includes some live microsnails, ‘Live snails’ were field- identified snails and slugs that were released on site or reared for identification, ‘‘Soil sample’ included primarily microsnails–mostly shells, but also live snails. (PDF) S2 Fig. Spatial pattern of live snail abundance across the 12 surveyed towns. The graph is based on snails counted and released during the visual survey and undercounts live micros- nails that were included in the shell or soil samples. (PDF) S1 Table. Twelve towns included in the regional survey. Population is based on the US Cen- sus Bureau (2018) estimates for 2016. Climatic data are means over a 20-yr period. Latitude and longitude are mean values for the ten yards sampled in each town. (PDF) S2 Table. Taxa list, native/non-native designation relative to Oklahoma and Kansas, and total count of each taxon for the 10 yards in the 12 towns in the survey. (PDF) S3 Table. Pairwise comparison results following PERMANOVA test of the Bray Curtis similarity of the yard-dwelling land snail populations in 12 towns, which produced 66 pair-wise comparisons. (PDF) Acknowledgments We are extremely grateful to the many residents who allowed us to survey their yards and appreciated their frequent offers of hospitality. We also thank the state extension agents and

others who helped find participating residents. Matthew Carman helped with field work, snail sorting and identification. Author Contributions Conceptualization: Elizabeth A. Bergey. Data curation: Elizabeth A. Bergey. Formal analysis: Elizabeth A. Bergey. Investigation: Elizabeth A. Bergey, Benjamin E. Whipkey. Methodology: Elizabeth A. Bergey. Writing – original draft: Elizabeth A. Bergey. Writing – review & editing: Benjamin E. Whipkey. References 1. McKinney ML, Lockwood JL. Biotic homogenization: a few winners replacing many losers in the next mass extinction. Trends Ecol Evol. 1999; 14: 450–453. https://doi.org/10.1016/s0169-5347(99)01679- 1 PMID: 10511724 PLOS ONE Diversity patterns of yard-dwelling snails across climate gradients PLOS ONE | https://doi.org/10.1371/journal.pone.0234830 August 28, 2020 15 / 18