%0 Generic %D 1998 %T Natural abundance of 15N in forests across a nitrogen deposition gradient %A Emmett, B.A. %A Kjønaas, O.J. %A Gundersen, P. %A Koopmans, C.J. %A Tietema, A. %A Sleep, D. %B Forest Ecology and Management %V 101 %P 9–18 %G eng