TY - Generic T1 - Reduced nitrogen has a greater effect than oxidised nitrogen on dry heathland vegetation Y1 - 2008 A1 - Van den Berg, L. J. L. A1 - Peters, C. J. H. A1 - Ashmore, M. R. A1 - Roelofs, J. G. M. KW - acidification KW - amino acids KW - ammonium toxicity KW - competition KW - decline KW - deposition KW - grass encroachment KW - herbaceous species KW - mesocosins KW - n enrichiuent KW - netherlands KW - nh4+/no3- ratios KW - nitrate KW - pinus-nigra KW - soil KW - vascular plants JF - Environmental Pollution VL - 154 IS - 3 ER -