Data from: Origin and demographic history of the endemic Taiwan spruce (Picea morrisonicola)

Taiwan spruce (Picea morrisonicola) is a vulnerable conifer species
endemic to the island of Taiwan. A warming climate and competition from
subtropical tree species has limited the range of Taiwan spruce to the
higher altitudes of the island. Using seeds sampled from an area in the
central mountain range of Taiwan, 15 nuclear loci were sequenced in order
to measure genetic variation and to assess the long-term genetic stability
of the species. Genetic diversity is low and comparable to other spruce
species with limited ranges such as Picea breweriana, Picea chihuahuana,
and Picea schrenkiana. Importantly, analysis using approximate Bayesian
computation (ABC) provides evidence for a drastic decline in the effective
population size approximately 0.3–0.5 million years ago (mya). We used
simulations to show that this is unlikely to be a false-positive result
due to the limited sample used here. To investigate the phylogenetic
origin of Taiwan spruce, additional sequencing was performed in the
Chinese spruce Picea wilsonii and combined with previously published data
for three other mainland China species, Picea purpurea, Picea
likiangensis, and P. schrenkiana. Analysis of population structure
revealed that P. morrisonicola clusters most closely with P. wilsonii, and
coalescent analyses using the program MIMAR dated the split to 4–8 mya,
coincidental to the formation of Taiwan. Considering the population
decrease that occurred after the split, however, led to a much more recent
origin.