Responses to light changes in seedlings of <I>Cupania vernalis</I> Cambess

Abstract

The seedlings of Cupania vernalis Cambess (Sapindaceae), a mid-sucessional species showed response to a set of contrasting irradiance environments, displaying plasticity to increasing light interception at lower light intensities (through increasing leaf area ratio and decreasing root/shoot ratio) and plasticity to increasing carbon gain and decreasing transpiration at high light intensities (through increasing rootlshoot ratio and decreasing leaf area ratio). Acclimation of seedlings transferred from high to low light and contrariwise was given through morphological and physiological adjustments in order that the plant which were transferred to the new irradiance should become similar to the control plants growing under the previous irradiance. The acclimation to decresing irradiance was faster than to increasing irradiance. These results can indicate that this species is not well adapted to suffer a increase in light intensity, similar to that occurring when a gap is forrned.