Fig. 3: Cross-plots of within-cave variability in dripwater and speleothem mean δ¹⁸O values with climate and cave data.

Cross-plots show low to no relationships between within-cave differences in dripwater (purple) or speleothem (green) mean δ¹⁸O values with variables: latitude, elevation, annual precipitation, aridity index, seasonality indices for precipitation and temperature, mean annual temperature, mean depth, and minimum distance from entrance for each cave. The lack of relationship with these variables, demonstrated also by the output from the multiple linear regression models in Supplementary Table 2, supports that karst hydrological heterogeneity is important over all climate types, cave depths and host rock types. Kendall’s tau values for each variable ranked against coeval dripwater and speleothem data are also shown, with p-values indicated in brackets. The p-values indicate that none of the relationships in are significant with the exception of elevation (SISAL; 95%) and mean depth (SISAL; 90%) although the Kendall’s tau values are low. Aridity and seasonality indices are dimensionless.