Figure 1.

Actual leaf N (N_L) distribution in the canopy of Japanese oak as a function of the leaf area index cumulated from the canopy top (F). Dashed line indicates optimal N_L distribution. Leaves were classified into four types based on their growth light environments (Q_int): (1) deep shade (triangle, 0 < Q_int < 3 mol m⁻² day⁻¹), moderate shade (diamond, 3 < Q_int < 15 mol m⁻² day⁻¹), moderate sun (square, 15 < Q_int < 25 mol m⁻² day⁻¹), and typical sun leaves (circle, 25 < Q_int < 35 mol m⁻² day⁻¹).