Fig. 4

Tree contents (means and standard errors in grams per tree) as a function of treatment and harvest date for a N and b TNC. Harvests 1 and 2 are represented by dark and pale grey bars, respectively. The contents of perennial organs are shown in squared areas and those of the current-year shoots by non-hatched areas. The effect of treatment and harvest date was tested by randomisation tests based on the generation of 2500 random orders. It was significant (5 % level) if coded with different letters