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.