Figure 2: Community-level spatial autocorrelation semivariogram.

A semivariogram plot of the decay in community similarity (as measured by the UniFrac community dissimilarity metric on the y axis) with increasing distance between samples. A UniFrac value of 1 indicates no shared community members between two samples and a value of 0 indicates 100% shared community members. The solid line is the variogram model fit, which tracks the predictable change in shared community membership with distance. The vertical dashed line is the distance of spatial autocorrelation (range), which is the maximum distance, according to the model, at which similarity in community composition between samples is correlated (in this case, 240 m). The horizontal dashed line represents the 'nugget,' which is the proportion of the change in community composition not explained by the spatial model. The inset demonstrates that, past the autocorrelation distance, there is no predictable change in community composition with distance.