@article {1567, title = {Effects of enhanced N deposition on Cladonia portentosa; results from a field manipulation study.}, number = {525 ISSN 0967-876X}, year = {2004}, pages = {51-62}, institution = {English Nature}, address = {Peterborough}, author = {Sheppard, L.I. and Leith, I.D. and Crossley, A.} }