Plants can utilize two major forms of inorganic nitrogen, nitrate (NO3–) and ammonium (NH4+), with some species appearing to ‘prefer’ one form over another, under certain conditions. Soil-N speciation has been shown to be an important determinant of species distribution, but no ecophysiologically realistic, mathematically sound model has yet emerged to describe and predict this phenomenon.
In a viewpoint article in Annals of Botany, Britto and Kronzucker suggest that this is because assignment of such preferences is not straightforward, and must take into account a wide array of complex physiological and environmental features, which interact in ways that are still not well understood.
