Fig. 4

Hypothesized relationships between environmental gradients, phosphorus uptake and plant size in A. wilhelmsii. Conditions characterized as colder, wetter and higher altitude impose selective pressures favoring plants with genetic adaptations for enhanced phosphorus uptake from soil. Over multiple generations, populations inhabiting areas associated with colder, wetter and higher altitude conditions evolve to absorb more phosphorus, allowing improved survival under stresses. Higher internal phosphorus levels optimize growth performance under colder, wetter and higher altitude conditions. In turn, increased phosphorus acquisition facilitates the evolution of larger plants through strengthened tolerance and competitive abilities, conferring adaptive advantages against populations from areas characterized as warmer, dryer and lower altitude exhibiting smaller sizes constrained by lower phosphorus absorption capacities.