Nitrogen stable isotopic composition of vegetation and soil in forests: tropical x temperate systems - Martinelli, Luiz Antonio; Piccolo, Marisa de Cassia; Vitousek, P M; Towsend, Alan R; Cuvas, E; Keller, M; McClain, M; McDowell, R.; Robertson, G P; Santos, O C; Treseder, K (New perspectives on nitrogen cycling in the temperate and tropical Americas: report of the International SCOPE Nitrogen Project, 1999)