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

Regional 3-second gridded models
Four models of vascular plant species compositional turnover were developed for case
study areas in eastern Australia (Figure 1) using 3-second gridded predictor data
(Table 6). The larger number of sites associated with the floristic survey data compiled
by NSW OEH required sampling of site-pairs for GDM analysis. Approximately 900,000
site-pairs were applied in the final model. Data from the local case studies derived
from CSIRO surveys were used with all site-pairs, after filtering by richness consistent
with the restricted survey methodology.
Geographic distance was a significant variable in all four models and proportionally
more important in the model applied to NSW (Table 7). Forty-one of the candidate
predictors were included in at least one model (Table 8). Monthly minimum
temperature (TNI) was particularly important as a predictor in southeast NSW and
maximum evaporation (EPX) for the model developed for the entire state. Among the
substrate variables kaolinite clay minerals in the lower soil horizon (KAO80) was a
significant predictor for the NSW model. The general structure of the fitted model for
each dataset is presented in Figure 17 and Figure 18.
Table A7-13. Summary of GDM model fitting for eastern Australian case study
areas using 3-sec gridded predictors.
Study # site- %Deviance Intercept Summed
# Richness
dataset pairs Explained
Coefficients predictors filter
NSW OEH 885,376 45.78 1.12 14.00 20 None
CSIRO SE
NSW
542,361 33.82 0.57 10.59 17 7 or more
Table A7-14. Relative contribution of predictor variable groups (sum of
coefficient values).
Study dataset
Climate
(including topoclimate)
Substrate Landform
Climate,
substrate and
landform
Geographic
Distance
NSW OEH 6.78 3.79 0.70 11.27 2.74
CSIRO SE NSW 5.70 1.65 1.67 9.02 1.57
Climate change refugia for terrestrial biodiversity 195