Landscape adaptations of forests
Comparative analysis can provide broader patterns for forest management,
where concurrent genetic and spatial patterns of local adaptation within
co-occurring tree species provides strong evidence for environmental
fitness and evolution (Bragg et al., 2015). Our analysis here identified
SNPs associated with both temperature and precipitation in jarrah; while
a similar study on a co-occurring species, marri (Corymbia
calophylla ), found SNPs associated with temperature to explain more
deviance than precipitation (Ahrens et al., 2019a), thereby suggesting
that temperature is a stronger driver of local adaptation for marri. It
is interesting that there were similarities in functional genes
associated with several adaptive variants between jarrah and marri
(e.g., ABC transporters and CBL gene families). Comparison of SNPs
across both species identified a set of 26 SNPs that were also found to
be associated with at least one of the five variables analysed (Table
S3). Most of these shared SNPs are associated with either
TMAX (16) or PWQ (12) in jarrah; while
for marri, the majority of the shared SNPs are associated with
TMAX (24), which is consistent with adaptation to both
temperature and precipitation in jarrah and with temperature in marri.
This comparison adds weight to our finding that the hypothesis of
precipitation as a more important driver than temperature in jarrah is
not supported
as our evidence indicates that both temperature and precipitation are
important climate factors for adaptation in jarrah.