211I generated PD rarefaction curves and ∆PD values for the mammal faunas of 71
of the 79 terrestrial ecoregions recognised by Olson et al. ( 2001 ) as constituting the
Australasian biogeographic realm. Data were sourced from the wildfinder database
(http://worldwildlife.org/pages/wildfinder)oftheWorldWildlifeFund.Eightecore-
gions were excluded from the analysis because they had less than two species and
thus a ∆PD value could not be calculated.
The ecoregions show huge variation in species richness and, as expected,
Phylogenetic Diversity is highly dependent on species richness (Fig. 6 ). Tropical
ecoregions(suchasthecentralrangeMontanerainforests,NewGuinea)havehigh
species richness and high Phylogenetic Diversity (Fig. 6 , Table 4 ).Whenconsider-
ing phylogenetic dispersion, however, other ecoregions show unusually high or low
values given their species richness (Table 4 ). The ecoregion with the lowest ∆PD is
theNewCaledoniadryforests.Becauseofitsisolation,thisfaunaconsistsexclu-
sively of bats and thus all the species are relatively closely related. The ecoregion
with the highest ∆PDwastheMountLoftywoodlandsofSouthAustralia,reflecting
relatively high numbers of marsupial species compared to the more tropically dis-
tributed bats and rodents.
5101520250300350400450500No. of sitesPhylogenetic Diversity (Ma)Tanami Desert
Uluru-Kata Tjuta NPFig. 5 Sample-based rarefaction curves for small mammal assemblages of sites in the Tanami
DesertandUluru-KataTjutaNationalPark,NorthernTerritory,Australia.SeeMortonetal.( 1994 )
for a description of the data. Phylogenetic beta diversity (∆PD) is higher among the Tanami sites
thantheUlurusites
The Rarefaction of Phylogenetic Diversity: Formulation, Extension and Application