Fig. 4.

Effects of different mycorrhizal inoculations on the inorganic and organic nitrogen uptake rates of orchid seedlings (6 months after inoculation) after tracers were injected at 2·5-cm (left) and 7·5-cm (right) soil depths. The values (means and s.e.) of four replicates are presented. Asterisks indicate a significant difference between the mycorrhizal fungi treatment (mycorrhizal seedlings) and the control treatment (non-mycorrhizal seedlings). Different letters indicate a significant difference between the mycorrhizal fungi treatments. These data represent the total uptake by the plant (above- and below-ground parts, including the endophyte), calculated per root d. wt per day.