Fig. 4: Histograms of Spearman’s correlation coefficient for fire and vegetation indices at Girraween lagoon.
From: Late Pleistocene emergence of an anthropogenic fire regime in Australia’s tropical savannahs
a, Relationship between MARSPAC and PARCHAR resampled for the natural fire regime (>30 ka; red bars) relative to the observed Spearman’s correlation coefficient (ρ) for the anthropogenic fire regime (<30 ka; blue vertical dashed line). b, Relationship between the percentage of C4 pollen and δ13CSPAC resampled for the natural fire regime (>30 ka; red bars) relative to the observed Spearman’s ρ for the anthropogenic fire regime (<30 ka; blue vertical dashed line). The relationships pertain only to samples where the TOC is >5.1%. The probabilities of generating the result randomly are 0.0071 (a) and <0.0002 (b) for this combination of thresholds. The regions shaded grey indicate ρ < 0.05. In both panels, x axes indicate the binned value of ρ for the relationship (indicated by ~) between each variable under the natural fire regime across all iterations. Solid black lines indicate probability density function describing the Gaussian shape of each histogram.
