Figure 4. Scatter plots of C and N ratios (a), C and P ratios (b), and N and P ratios (c) of the algal cells. The molar C:N = 6.6:1, 12:1, 15:1 ratios (a), molar C:P = 106:1, 160:1, 300:1, and 600:1 ratios (b), molar N:P = 10:1, 16:1, and 30:1 ratios (c) are shown as solid lines. White dots represent control treatments and gray dots represent amended treatments. The numbers in the dots represent the tree species ID shown in Table 1.