According to the model (I), mycorrh

According to the model (I), mycorrhizal symbiosis can be favoured at low nutrient
concentrations if mycorrhizal roots had a lower threshold value of nutrient uptake (lower
xmin), but only with relatively high nutrient use efficiency of photosynthesis (PNUE)
values (Fig. 2a). At higher soil nutrient concentrations only the non-mycorrhizal strategy
prevailed. If mycorrhizal roots had higher maximum capacity of nutrient uptake (higher
Vmax) then non-mycorrhizal strategy was favoured at the lowest PNUE and soil nutrient
concentration values (Fig. 2b). When soil nutrient concentration increased, the advantage
of mycorrhizas increased steeply and they were favoured with all other, but not at the
lowest PNUE-values. If mycorrhizal roots had higher affinity of uptake (lower halfsaturation
constant, Km) then mycorrhizal symbiosis was favoured at intermediate
nutrient concentrations, but only at relatively high PNUE values (Fig. 2c).