Species difference of transpiration in three urban coniferous forests in a semiarid region of China

•The stand transpiration of Pinus tabulaeformis and Pinus sylvestris decreased significantly under drought stress, while Picea meyeri maintained relatively stable transpiration.•Soil water availability alters the urban forest transpiration response to climatic conditions, such as vapor pressure deficit.•Pinus tabulaeformis had stronger stomatal regulation than Pinus sylvestris and Picea meyeri.•Pinus tabulaeformis and Pinus sylvestris consumed more soil water than Picea meyeri at the beginning of growing seasons.