title: Ecological significance and complexity of N-source preference in plants.
abstract: BACKGROUND
  Plants can utilize two major forms of inorganic N: NO3(-) (nitrate) and NH4(+) (ammonium). In some cases, the preference of one form over another (denoted as β) can appear to be quite pronounced for a plant species, and can be an important determinant and predictor of its distribution and interactions with other species. In many other cases, however, assignment of preference is not so 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.
  
  
  METHODS
  This Viewpoint presents a discussion of the key, and often co-occurring, factors that join to produce the complex phenotypic composite referred to by the deceptively simple term 'N-source preference'.
  
  
  CONCLUSIONS
  N-source preference is much more complex a biological phenomenon than is often assumed, and general models predicting how it will influence ecological processes will need to be much more sophisticated than those that have been so far developed.
authors.affiliation: Department of Biological Sciences, University of Toronto, 1265 Military Trail, Toronto, Ontario, Canada M1C 1A4.
authors.forename: Dev T
authors.initials: DT
authors.lastname: Britto
authors.forename: Herbert J
authors.initials: HJ
authors.lastname: Kronzucker
mesh_terms: D064751:Ammonium Compounds / Q000378:metabolism*; D004463:Ecology; D004777:Environment; D008954:Models, Biological; D009566:Nitrates / Q000378:metabolism*; D009584:Nitrogen / Q000378:metabolism*; D018521:Plant Physiological Phenomena; D018517:Plant Roots / Q000378:metabolism; D010944:Plants / Q000378:metabolism*; D012987:Soil; D013045:Species Specificity
chemical_list: D064751:Ammonium Compounds; D009566:Nitrates; D012987:Soil; D009584:Nitrogen
keywords: Ammonium; N-source preference; amino acids; competition; complexity; nitrate; soils; succession