Figure 1. Provenance differences in leaf functional traits of four tropical tree species grown under common environmental conditions. Panels show (a) leaf width, (b) stomatal conductance,g _s, (c) leaf inclination angle, and (d) thermal time constant, τ. Species include Ca = Castanospermum australe, Hn = Homalanthus novo-guineensis, Me = Melicope elleryana, and Tm = Terminalia macrocarpa . Data represent tree averages (n =6) presented as box and whisker plots showing median and interquartile range, with the average marked by ×. Results of intraspecific t-test of provenance differences indicated by subscript ns=not significant, * p < 0.05, ** p < 0.001, and *** p < 0.0001.