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

annual variation. Thus precipitation alone was not a particularly useful metric for
identifying refugia.
Places that have been climatically stable over the last few million years are typically
places of high species endemism and lineage-level diversity. We examined
paleological stability in temperature and resolved a number of clear paleological
temperature refugia at the continental scale. These areas were found in the north and
west of the continent; parts of the continent where no clear temperature refuge will
exist in 2085. Thus, we can infer that we currently stand to lose much of the specieslevel
and lineage-level diversity that has accumulated in Australia over the last few
million years.
Moving on from analysis of raw climatic variables, we modelled the projected rangeshift
of 1700 vertebrate species across the continent. This exercise confirmed that the
same areas identified from the temperature analysis (above) would act as refugia for
biodiversity. Again, large areas of the south and east of the continent (associated with
the Great Dividing Range), and a small area in central Australia and the south-west are
predicted to be refugia under projected climate change. These areas all have a
relatively low outright loss of species, and a relatively high influx of immigrant species
from surrounding areas.
Overall, then, we conclude that substantial refugial areas exist in the south and east of
the continent, as well as smaller areas in central Australia and the far south-west. Many
of these refugia are also areas that are heavily modified by human activities, so
management action to facilitate species movement and persistence in these areas is
recommended. We also conclude that there is a large portion of Australia’s vertebrate
fauna that will have no ready access to natural refugia in 2085, and these species are
at particular risk of extinction.
To clarify these broad findings at the regional level and determine how we might
progress with research efforts, we examined four case studies.
The first of these case studies (led by the CSIRO Climate Adaptation Flagship) is an
extensive demonstration of the application of compositional-turnover modelling to
identify locations of potential refugia at relatively fine spatial resolutions. It uses new
techniques for deriving and projecting topographically adjusted radiation, climate and
moisture surfaces. This approach was applied to the entire Australian continent at 250metre
grid resolution, using the best available biological datasets for a wide range of
plant, vertebrate and invertebrate taxa. To demonstrate potential applicability at even
finer grid resolutions, and using higher quality biological data, the approach was also
trialled using comprehensive floristic-survey datasets for all of New South Wales, and
for the Tingle Mosaic area in south-west Western Australia.
The second case study (led by the Centre for Biodiversity Analysis at Australian
National University) examines how we might rapidly assess the location of current
species- and lineage-level diversity for particular ecological communities (in this case,
rainforest-endemic lizards). These analyses rest on reconstruction of the paleological
distribution of the community and the identification of areas that have been suitable for
that community over the long term. These most stable areas are likely to be
storehouses of lineage-level diversity, and often also contain unique endemic species.
These evolutionary refugia were strongly skewed to higher elevations, which suggests
firstly that the places which functioned as refugia from past climate change may be
similar to those predicted to be refugia under projected climate change, but secondly,
that there are particular concentrations of endemic diversity in these threatened high
elevation zones. By adequately assessing the location of this (often cryptic) diversity,
Climate change refugia for terrestrial biodiversity 3