To investigate how well leaf gas exchange of species responses to the different light environments , the authors use an open gas exchange system, CI-310 Portable Photosynthesis System to study the photosynthetic response of the shrub Mahonia fortunei in the limestone area of Chongqing. Photosynthetic rate (Pn), transpiration rate (E), intercellular CO 2 concentration (Ci), stomatal conducutance (Gs), water use efficiency (WUE) and light use efficiency (QUE) were examined under different photosynthetic ra...