TY - RPRT T1 - Effects of enhanced N deposition on Cladonia portentosa; results from a field manipulation study. Y1 - 2004 A1 - Sheppard, L.I. A1 - Leith, I.D. A1 - Crossley, A. JF - Lichens in a Changing Pollution Environment, English Nature Workshop PB - English Nature CY - Peterborough ER -