Plant transpiration modifies climatic conditions at the land surface and in the soil during the vegetative season (Eagelson 1987, Pokorný 2001). In mountainous areas of Central Europe transpiration recycles about 50% of the rainwater during the vegetative season. Evaporative cooling induced by transpiration reduces the maximum plant surface temperature by about 15C on a hot and dry day.Dissipation of solar energy in a landscape controlled by plant transpiration is the core of the terrestrial hydrologic cycle. Transpiration is substantially influenced by the form and functioning of the vegetation cover. ...