Atmospheric nitrogen (N) deposition alters nutrient availability and ecosystem productivity in many systems. In temperate forests phosphorus (P) is a secondary limiting nutrient and its cycling receives less study. P and N may interact to determine productivity such that ecosystems receiving high rates of N deposition may become limited by P. Northern hardwood forests in the eastern US receive high rates of N deposition and exhibit species-specific influences on N cycling and responses to N additions. We examined how N deposition and tree species alter P pools. N deposition was simulated by adding NH4NO3 (50 kg ha-1 yr-1) to single species plots of Quercus rubra L., Acer saccharum Marsh., Tsuga canadensis (L.) Carr., Fagus grandifolia Ehrh., and Betula alleghaniensis Britt. in the Catskill Mountains, New York from 1997 to 2006. Phosphorus in microbial biomass (PMIC), fine roots (PROOT) and soil solution (captured by anion resins, PRES) were measured in summer 2006. PMIC was unaffected by N fertilization or species (p=0.24, p=0.18). PROOT exhibited species effects (F=6.22, p<0.01) but no fertilization effects (p=0.15). Organic horizon PRES was greater (F=4.97, p<0.05) in fertilized plots of all species except Q. rubra. Mineral horizon PRES differed among species (F=4.49, p<0.01), with A. saccharum plots having the highest and T. canadensis plots the lowest, but was unaffected by fertilization (p=0.22). In organic horizons added N may stimulate microbial activity resulting in greater P mineralization. In mineral horizons physical mechanisms like greater P sorption and pH-related declines in P solubility may dominate P availability.