Biodiversity consequences of genetic variation in bark characteristics within a foundation tree species
Barbour, RC and Forster, LG and Baker, SC and Steane, DA and Potts, BM, Biodiversity consequences of genetic variation in bark characteristics within a foundation tree species, Conservation Biology, 23, (5) pp. 1146-1155. ISSN 0888-8892 (2009) [Refereed Article]
The developing field of community genetics has the potential to broaden the contribution of
genetics to conservation biology by demonstrating that genetic variation within foundation plant species can
act to structure associated communities of microorganisms, invertebrates, and vertebrates. We assessed the
biodiversity consequences of natural patterns of intraspecific genetic variation within the widely distributed
Australian forest tree, Eucalyptus globulus.We assessed genetic variation among geographic races of E. globulus
(i.e., provenances, seed zones) in the characteristics of tree-trunk bark in a 17-year-old common garden and
the associated response of a dependent macroarthropod community. In total, 180 macroarthropod taxa were
identified following a collection from 100 trees of five races. We found substantial genetically based variation
within E. globulus in the quantity and type of decorticating bark. In the community of organisms associated
with this bark, significant variation existed among trees of different races in composition, and there was
a two-fold difference in species richness (7–14 species) and abundance (22–55 individuals) among races.
This community variation was tightly linked with genetically based variation in bark, with 60% of variation
in community composition driven by bark characteristics. No detectable correlation was found, however,
with neutral molecular markers. These community-level effects of tree genetics are expected to extend to
higher trophic levels because of the extensive use of tree trunks as foraging zones by birds and marsupials.
Our results demonstrate the potential biodiversity benefits that may be gained through conservation of
intraspecific genetic variation within broadly distributed foundation species. The opportunities for enhancing
biodiversity values of forestry and restoration plantings are also highlighted because such planted forests are
increasingly becoming the dominant forest type in many areas of the world.