Assessing leaf level processes in the context of other hierarchical levels (e.g., whole-plant, canopy, species, and landscape) is a current focus of ecophysiologists, and a discipline requiring additional research. The primary study objective was to examine foliar responses to light gradients (i.e., photosynthetically active radiation, PAR) across different species, age classes, and vertical positions in two landscapes: the northern deciduous forests of Wisconsin (CNF) and the Ozark highlands of southeastern Missouri (Ozarks). We measured the photosynthetic response of several light curve characteristics (e.g., maximum photosynthetic rate (Amax), stomatal conductance at Amax (gsmax), apparent quantum yield (f), and compensation point (G), and dark respiration rate (RD)) changes in microclimate (e.g., vapor pressure deficit (VPD), temperature, and fraction of PAR intercepted (fPAR)), leaf (e.g., SPAD chlorophyll concentration, (SCL)), and canopy characteristics (e.g., canopy openness) of ten tree species in two climatically different landscapes. Species include bigtooth aspen, paper birch, red oak, red maple and sugar maple (CNF) and shortleaf pine, hickory, scarlet, black, and white oaks (Ozarks). Three stand age classes (i.e., young, intermediate, and mature) were measured for all species in CNF. Stand age (CNF), species, and canopy position significantly affected a majority of the photosynthetic characteristics (a = 0.10). Furthermore, photosynthetic characteristics of shade intolerant species were typically greater than shade tolerant (p < 0.0001 to 0.0999). In CNF, there were no significant effects of age on gsmax and Amax, but there were significant two-way interactions of species and age (p <0.0001). This result indicates within CNF gsmax and Amax of species react differently to stand maturation. For example, paper birch gsmax and Amax decrease with age, while increasing with age in the bigtooth aspen. In the Ozarks only species and canopy positions were compared due to incomplete data; subsequently most photosynthetic characteristics differed significantly (a = 0.10) by age and species. In both landscapes, the upper canopy positions typically experienced greater photosynthetic capability compared to lower positions (p <0.0001 to 0.0125). In both landscapes canopy and foliar characteristics were capable of predicting photosynthetic characteristics of each species, especially in mature stands (r2 = 0.52 to 0.99). Interactions of physiological and environmental properties affected photosynthetic characteristics uniquely for each species. SLW in both landscapes was the best predictor of photosynthetic characteristics (i.e., highest direct and indirect values), which was potentially due to it similar reaction to light as compared to photosynthetic characteristics. The photosynthetic, leaf, and canopy characteristics of ten species in two landscapes varied significantly by age and canopy position. The variations typically mimicked changes in microclimatic conditions within the canopy, especially the light environment. Carbon models that include intra- and inter-specific species physiological variation will benefit from these results, especially when considering global and regional climate change.