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

among Ponca City, Norman, Ardmore, and Idabel) or were western (the combination of Woodward and Elk City; Fig 6). A distance decay pattern was evident as the Sørensen similarity of snail assemblages decreased with increasing distance among towns (exponential decay regression: p < 0.001, R2 = 0.35; Fig 7). Following Baselga [39], this distance decay relationship is also illustrated as dissimilarity, which increases with distance (linear regression: Fig 8A). Simpsons dissimilarity, a measure of species replacement, likewise increased with distance (p < 0.001, R2 = 0.389; Fig 8B). Nestedness (within the dissimilarity index) was little related to distance among towns (p = 0.50, R2 = 0.007; Fig 8C). Fig 4. Patterns of snail assemblage attributes across the survey area. (A) Snail and shell abundance. (B) Species richness. Small circles show location of towns included in the survey. https://doi.org/10.1371/journal.pone.0234830.g004 PLOS ONE Diversity patterns of yard-dwelling snails across climate gradients PLOS ONE | https://doi.org/10.1371/journal.pone.0234830 August 28, 2020 8 / 18