Mean (SE) for net CO₂ assimilation (A), stomatal conductance of water vapour (g_wv) and intrinsic water use efficiency (WUE_i) for well-watered seedlings and well-watered seedlings after two dry-down cycles from seven western redcedar populations. Population means for each parameter that do not share the same letter (uppercase for well-watered & lower case for drought recovery) are significantly different (P < 0.05 Fisher’s LSD test). See Table I for population details.