Abstract
Sedum species, which possess the CAM metabolism, are widely utilized for extensive green roofs as they are tolerant to drought environments. Especially, naturalized species, Sedum mexicanum and S. acre, are most intensively used. In this study we compared transpiration rates of three Sedum species that naturally habitat in Japan, S. makinoi, S. bulbiferum and S. polytrichoides subsp. yabeanum var. setouchiense to four naturalized species, S. mexicanum, S. acre, S. lineare and S. sarmentosum to evaluate their adaptability to roof environments.
Transpiration rates of S. makinoi and S. polytrichoides subsp. yabeanum var. setouchiense were very slow and comparable to four naturalized species, indicating their adaptability to roof environment in terms of water use efficiency. Contrary, the transpiration rate of S. bulbiferum was approximately 10-fold higher than those of other species. This suggests that S. bulbiferum shows relatively low adaptability to roof environments and higher evaporative cooling ability of buildings.
