Gas exchange of Sedum lineare under drought condition Behavior Study of NAD-Malic Enzyme in Facultative CAM Plants Studies on the Physiological Response of Sedum hybridum Cutting Seedlings to Drought Stress DURING THE BEGINNING OF THE LIGHT PERIOD PATHWAY OF CO_2 FIXATION IN THE CAM PLANT LEAF AGE AND THE CAM ACTIVITY IN SEDUM SPECTABILE Ecophysiological adaptation of green roof plant Sedum lineare to temperature variation