Fig. 4: Machine learning predictions of seasonal P concentration and cellulose/lignin ratio of leaf-tissue samples.

a The seasonal dynamics of P concentration available to plants based on a machine learning analysis of leaf tissue spectral properties from the two field experiments at 3rd Street and Red River, with the p-values from two-sample tests labeled above the boxes. P-values derived from pairwise comparisons are shown on the horizontal lines. b Cellulose/lignin (C/L) ratio of leaf-tissue samples collected from the two field experiments at 3rd Street and Red River. Overall, the ratios are significantly higher (p = 0.0023) in Red River than those in 3rd Street. P-values derived from pairwise comparisons are shown on the horizontal lines.