ALLOCATION OF CARBON AND NITROGEN AS A FUNCTION OF THE INTERNAL NITROGEN STATUS OF A PLANT - MODELING ALLOCATION UNDER NON-STEADY-STATE SITUATIONS

In this paper we model allocation of carbon and nitrogen to roots and leaves as a function of the nitrogen status of a plant. Under steady-s tate conditions, allocation of carbon and nitrogen to leaves is expone ntially (positively) correlated with plant nitrogen concentration, whe reas allocation to roots is correlated negatively, also in an exponent ial manner. Allocation functions derived under steady-state conditions are used to simulate biomass partitioning under non-steady-state nutr ient conditions. Upon nitrogen deprivation, measured and simulated val ues are rather similar with time, suggesting that allocation functions derived under steady-state conditions also hold under non-steady-stat e conditions.