Fig. 5: Effects of rock and soil Ca on multiple soil functions within Ca-rich parent materials.
From: Calcium-rich parent materials enhance multiple soil functions and bacterial network complexity
a Regressions between the number of soil functions exceeding a given threshold and rock or soil Ca. Thresholds were defined as percentages (5–99% at 1% increments) of each function’s maximum observed value (calculated as the mean of the top four measurements). Colors represent different threshold levels, with cooler colors indicating lower thresholds and warmer colors indicating higher thresholds, as detailed in the figure legend. b Slope of the relationship between the number of soil functions exceeding a given threshold and rock or soil Ca across threshold values (x-axis). Points represent fitted slope values (i.e., the slope of the regression between the number of soil functions and the explanatory variable at each threshold), with shaded areas denoting the 95% confidence interval. A slope and its confidence interval both above zero denote a positive effect of the predictor on soil functions. Rock Ca rock calcium content, Rock Ca/Mg the ratio of rock total calcium to magnesium, Soil Caex soil exchangeable calcium, soil Ca/Mg the ratio of soil total calcium to magnesium.
