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4.5 Discussion
Although computational challenges eventually constrained the number of biological
groups that could be fully analysed at continental scale for this report, this case study
has clearly demonstrated the important contribution that compositional-turnover
modelling can make to assessing refugial potential across a wide range of biological
taxa and spatial resolutions. The analysis here also demonstrates the importance of
considering finer-scaled effects of topography on local climate when identifying and
mapping potential refugia. Failure to consider such effects risks underestimating the
potential for biodiversity to persist in topographically heterogeneous landscapes and, in
turn, the relative importance of these areas for conservation attention. Such effects are
likely to be particularly relevant for biological groups with limited dispersal capacity, and
the results of this study therefore complement those of the species modelling work
presented elsewhere in this report (which focussed on vertebrate groups with relatively
good dispersal capacity, particularly in the case of birds and mammals).
A few trends emerging from the continental analyses of refugial potential are worth
noting:
Locations of potential refugia appear to be quite sensitive to the choice of climate
scenario (Figure 37), which points to the importance of considering multiple scenarios
in developing robust ‘no-regrets’ mapping of refugia for conservation planning.
Locations of potential refugia also appear to exhibit some marked differences between
biological groups (Figure 38), pointing to the desirability of extending the refugial
analyses completed here to encompass the remaining 11 groups for which GDM
models have been fitted in the current study.
Potential refugia can occur in a wide variety of situations (Figure 39 to Figure 44)
including for example: areas of higher elevation relative to the surrounding landscape
(e.g. mountain tops); topographically sheltered locations; areas close to the ocean; and
areas likely to remain moister than surrounding landscapes due to hydrological factors
(e.g. in the Channel Country).
Many areas of high refugial potential are already included within reserves, but many
others are not (Figure 45 and Figure 46), and these exclusions therefore deserve
closer attention in future conservation prioritisation efforts.
The two finer-scaled analyses — NSW at 100 m grid resolution, and the Tingle Mosaic
at 30 m resolution — have served the intended purpose of demonstrating potential
applicability of the analytical approach to higher quality biological and environmental
datasets. However, the results of these analyses (Figure 47 and Figure 48) should be
regarded as indicative only. Further work will be required before outputs such as these
can be regarded as having a sufficient level of rigour to inform planning and decisionmaking
at these scales.
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