@article {810, title = {Long term effects of ammonium sulphate on Calluna vulgaris}, journal = {Journal of Applied Ecology }, volume = {34}, year = {1997}, pages = {208-216}, author = {Uren, S.C. and Ainsworth, N. and Power, S. and Cousins, D.A. and Huxendurp, L.M. and Ashmore, M.R.} }