determining the response of mountain maple (acer spicatum l.) to increases in light is confounded by interaction with other environmental factors. rising atmospheric carbon dioxide concentrations ([co2]) and the accompanying global warming and soil moisture depletion are expected to have large impacts on plants, including mountain maple, responses to their biological and physical environments. yet the effects of global climate change factors on mountain maple response to light is ignored. mountain maple seedlings were grown in two light regimes (low or shaded and high or unshaded), two [co2] (ambient: c 380 μmol mol-1 and elevated: 760 μmol mol-1). using soil temperature manipulation equipment (17 and 22°c), i tested the effects of [co2] and tsoil on the physiological and morphological responses of mountain maple to light. secondly, soil moisture treatment was applied to another set of seedlings to test the effects of [co2] and soil moisture on the physiological and morphological responses of mountain maple to light.