Data from: Genetic structure in a fragmented Northern Hemisphere rainforest: large effective sizes and high connectivity among populations of the epiphytic lichen Lobaria pulmonaria

An extraordinary diversity of epiphytic lichens is found in the boreal
rainforest of central Norway, the highest-latitude rainforest in the
world. These rainforest relicts are located in ravine systems, and clear
cutting has increased the distance between remaining patches. We
hypothesized that the relatively small lichen populations in the remaining
forest stands have suffered a depletion of genetic diversity through
bottlenecks and founder events. In order to test this hypothesis we
assessed genetic diversity and structure in populations of the tripartite
lichen Lobaria pulmonaria using eight SSR loci. We sampled thalli growing
on Picea abies branches and propagules deposited in snow at three
localities. Contrary to expectations, we found high genetic diversity in
lichen and snow samples, and high effective sizes of the studied
populations. Also, limited genetic differentiation between populations,
high historical migration rates, and a high proportion of first generation
immigrants were estimated, implying high connectivity across distances
<30 km. Almost all genetic variation was due to variation within
sites; spatial genetic structures within populations were absent or
appeared on small scales (5–10 m). The high genetic diversity in the
remaining old boreal rainforests shows that even relict forest patches
might be suitable for conservation of genetic diversity.