Nonlinear increases in water-use efficiency near maximum height: their influence on inferred CO2 response

John Marshall, SLU Swedish University of Agricultural Sciences Umea, Umeå, Sweden, Giustino Tonon, Free University of Bozen-Bolzano, Bolzano, Italy, Roberto Tognetti, Ambiente e Alimenti Università degli Studi del Molise Via Francesco De Sanctis, Dipartimento di Agricoltura, Campobasso, Italy and Francesco Giammarchi, Free University of Bozen, Forest Ecology and Silviculture, Bozen, Italy