Table 2 Best-fit models (all P < 0.001, F-statistic) for accumulation of litter mixtures (leaves, twigs, bark) in eucalypt forests and woodlands at continental scale (XTsf (g m2) = I + aTsf + bTsf2 + cAI + dQlf)

From: Litter accumulation and fire risks show direct and indirect climate-dependence at continental scale

Eucalypt forest/species

n

I

a

b

c

d

R2

All Tsf

All eucalypt forests

119

699 n.s.

29.4 ***

−0.11 ***

1117 ***

-1303 **

0.44

Representative forests 1

85

862 n.s.

35.7 ***

−0.13 ***

748 n.s.

1107 n.s.

0.45

Tsf <40 years

All eucalypt forests

108

766 n.s.

129***

−3.02***

1032***

-1806***

0.59

Representative forests 1

78

435 n.s.

163***

−4.09***

984*

-1341*

0.65

  1. 1E. regnans data were excluded as there were too few observations to compute Qlf (See also SI Table 1).
  2. Independent variables (fixed effects) are elapsed time (since last fire, Tsf, years), aridity index (AI) and quality of litterfall (Qlf). AI and Qlf are defined in Methods. I = intercept, a–d are coefficients, n = number of replicates. For coefficients: *** = P<0.001, ** = P<0.01, * = P <0.05, n.s. = not significant (P > 0.05). All coefficient P values are based on t-statistics and two-sided test. As described in Methods, limited data for longer Tsf is a significant determinant of model performance. Models based on data for all eucalypt forests and all Tsf can be used for making predictions at continental scale. For comparative purposes, we include models where data is limited to (a) 40 years of elapsed time and (b) our Representative forests.
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