Fig. 1. Nutritional interpretations of directional changes with time in dry mass, nutrient content, and nutrient concentration during plant development. The reference point (R) represents an initial plant sample taken at time T0 (usually normalized to 100). Vector orientation and magnitude characterize parameter relationships [increase (+), decrease (-), or unchanging (0)] relative to seedlings sampled at subsequent time intervals. Arrow direction also depicts time progression from time T0 to T1, T2... A new Shift G, characterizing net depletion often associated with retranslocation, is included in the box (Modified from Imo and Timmer, 1997; Malik, 1998)
