Agashashok White Spruce Needle Gas Exchange 2007-2008, Version 1.0

This dataset includes measurements of white spruce needle gas exchange made under conditions of saturating light, ambient CO2 and optimum temperature. Also included are needle C and N concentrations and needle d15N and d13C. Measurements were made at breast height on 36 trees exposed to 4 experimental treatments established in June of 2006 (i.e., n=9): control, fertilized, watered and fertilized x watered. Fertilized trees received 5 g N m-2 yr-1 applied as granular NH4NO3, 2 g P m-2 yr-1 applied as granular P2O5 and 4 g K m-2 yr-1 applied as granular K2O. The watering experiment was carried out using a passive throughfall displacement system that increased the size of each precipitation event (~2x). The study site is on a terrace next to the Agashashok River, Noatak National Preserve, AK (67.477, -162.216).