Small-scale genetic structure and breeding dynamics in the Mojave Desert moss, Syntrichia caninervis

<italic>Syntrichia caninervis</italic> is a dominant moss in the Mojave Desert, where it plays an important role in the composition of biotic soil crusts. To date, it has been assumed that individual patches of this moss species represent multiple branches of the same clone (individual genotypes). Here we characterize the fine-scale genetic structure of S. caninervis in a population located at Sheep Creek, using microsatellite loci to assess individual branches and sporophytes' genotypes and the relatedness of individuals within two 1 m x 1 m grids separated by approximately 200 m. From these data we assess paternity, and estimate fertilization distance from inferred paternal genotypes to sporophyte offspring. The hierarchical AMOVA highlighted higher variance overall between patches than between the grids. We found a strong positive correlation between spatial and genetic distance in the samples. We expect these results to further advance the research of the genetic diversity of <italic>S. caninervis</italic>.