Figure 3. C (a), N (b), and P (c) cell quotas of algae incubated in culture media prepared from leaf litter leachates of 11 tree species. White boxes are control incubations and gray boxes are amended incubations. Boxes are arranged according to the P mass content in leaf litter from low to high within broadleaf and coniferous groups as in Table 1. Asterisks indicate that there is a significant difference between control and amended incubations (p < 0.05). Different letters indicate a significant difference between control treatments of different leaf litter leachates.