@article {1481, title = {Decline of acid-sensitive plant species in heathland can be attributed to ammonium toxicity in combination with low pH.}, journal = {New Phytologist}, volume = {166}, year = {2005}, pages = {551-564}, author = {Van Den Berg, L.J. and Dorland, E. and Vergeer, P. and Hart, M.A.C. and Bobbink, R. and Roelofs, J.G.} }