We examined the physiological performance and growth of Pinus strobus L. seedlings the first growing season after planting on two clear-cut and burned sites in the southern Appalachians. Growth of the seedlings was related to physiological measurements (net photosynthesis (Pn) transpiration, leaf conductance, and xylem water potential), soil water, foliar N, seedling temperature, and light environment using regression analysis. Diameter growth increased with increasing foliar N concentration and decreased as competitor biomass increased. Competition reduced growth by lowering foliar N, shading seedlings, and possibly reducing photosynthetic capacity. Increased temperature and lower available soil water may obscure these relationships on a harsh site.