Williams-Climate-change-refugia-for-terrestrial-biodiversity_0

Figure 16: An example of a species distribution model for 1990, and the median
across projected distributions for each of the 18 GCMs are shown for RCP8.5 at
2085. The example species is three-clawed worm-skink, Anomalopus verreauxii.
3.4.7.3 Species richness
Species richness for 1990 was calculated by summing the binary presence/absence
models for each species across all four taxonomic groups. For future projections of
species richness, the species model for each of the GCMs was summed to provide a
species richness model per GCM. Species richness across the 18 GCMs were then
summarised for the 10 th , 50 th (median) and 90 th percentiles. The median of future
outputs are shown here, the 10 th and 90 th percentile outputs are detailed in APPENDIX
4. Projected species richness variability. The proportion change in species richness
between 1990 and 2085 (Figure 17) was calculated by dividing the current species
richness model by the 2085 median richness model. Shifts are apparent across all
species for the species richness model between 1990 and 2085: central, north and
west Australia are projected to decrease in species richness, whereas the south-east
and parts of the north-east are projected to increase in species richness. A notable
exception to the overall declines projected for central Australia can be found in the
MacDonnell Ranges and Burt Plains area of the Northern Territory. The largest areas
projected to see increases in species richness are the Nullarbor, Gawler and Flinders
Lofty Block in South Australia, the uplands Victoria and southern NSW, and much of
Tasmania. Importantly, the proportional change in species richness across all taxa
identifies broadly the same areas as the climate distance metric (section 3.4.2). That is,
the areas the distance metric predicts as major refugia (Figure 12), also appear as
places where a large influx of species is predicted to occur.
30 Climate change refugia for terrestrial biodiversity