Nitrogen deposition increases the acquisition of phosphorus and potassium by heather Calluna vulgaris

Increased plant productivity due to nitrogen pollution increases the strength of the global carbon sink, but is implicated in plant diversity loss.
However, modelling and experimental studies have suggested that these effects are constrained by availability of other nutrients. In a survey of
element concentrations in Calluna vulgaris across an N deposition gradient in the UK, shoot concentrations of N and more surprisingly phosphorus
and potassium were positively correlated with N deposition; tissue N/P ratio even decreased with N deposition. Elevated P and K concentrations
possibly resulted from improved acquisition due to additional enzyme production or mycorrhizal activity. Heather occurs on organic
soils where nutrient limitations are likely due to availability constraints rather than small stocks. However, if this effect extends to other plant and
soil types, effects of N deposition on C sinks and plant competition may not be as constrained by availability of other nutrients as previously
proposed.