Transpiration

Abstract Transpiration is the evaporation of water from the plant to the atmosphere. In case of open stomata, transpiration from a leaf is schematically outlined. Relationships among meteorological factors such as the wind speed and the solar radiation, physiological activities, and the transpiration are described. Some effects of transpiration on plants are also pointed out. One is to increase the absorption of minerals from the soil, and another is to decrease the leaf temperature to prevent a high‐temperature stress. For the plant canopy, the total of transpiration from plants and evaporation from the wetted surfaces of plants and soils is described as evapotranspiration. Transpiration and evapotranspiration from plant canopy has the different seasonal and diurnal patterns, depending on various climatological and meteorologicaly conditions. These quantitative data about transpiration and evapotranspiration from plant vegetations are very important for forestry and landscape management, irrigation management, and prediction of climatic change. Finally, some measurement methods of transpiration from the single leaf, the individual plant, and the canopy level are presented shortly.