Spatial autocorrelation
Spatial genetic differences as a result of isolation by distance (IBD)
were analyzed by computing a Mantel test Pearson’s product-moment
correlation (Mantel, 1967) between a pairwise population genetic
distances matrix
[F ST/1-F ST; Rousset,
1997] and geographical distance between sampling localities
[log(Euclidean distance)]. Genetic and geographic distances were
computed using the functions gl.ibd from the dartR package
(Gruber et al., 2018), and the statistical Mantel test using the
functions from the package vegan (Oksanen et al., 2016). For this
test, the significance values were calculated from 999 random
permutations. Isolation by distance was examined for all population
pairs, and within pairs of populations in small and large patches
separately.