ORNL FACE Nitrogen Concentrations (Leaves, Litter, Fine Roots, Wood)

This report documents the file, Nconc.dat, which contains the nitrogen concentration data for leaves, litter, fine roots, and wood for 1998-2006. These data were collected for rings 1 and 2 which are exposed to elevated CO2 and rings 3-5 which have ambient CO2.The 2005 and 2006 nitrogen concentrations for fine roots will be included when they become available. The N concentration in leaves could not bemeasured in ring 5 in 2006; an estimated value based on N concentration in litter and an average resorption efficiency is 1.073%.Additional information describing this dataset can be found in Norby, R.J. and C.M. Iversen (2006). Nitrogen uptake, distribution, turnover, and efficiency of use in a CO2-enriched sweetgum forest. Ecology 87:5-14.