Institute of Ecology of Nature Systems, Tatarstan Academy of Science, Daurskaya ul. 28, Kazan 420087, Russia

Abstract

One of the characteristic feature of activity of plant organism vital functions is a speed of its inner water flow. The main source of energy providing the transport of water is gradient of water chemical potential between soil and atmosphere. In case of equal potentials of these surroundings, the plant organism have additional energetic expenses to compensate the energy of external source. Series of experiments to investigate the influence of saturation of atmosphere with water (equilibrium of potentials) to energetic balance of plant were carried out. The results shows that: 1) etiolate seedlings in this conditions waste 10-15 percent energy per unit of new formation more than under 70-80 percent humidity; 2) saturation of atmosphere with water above plants with well developed transpiration surface leads to the decrease in their heat content; 3) equilibrium of water chemical potentials of different environments increases the intensity of intact root transpiration, i.e. intensifies "the burning" of organic matter. Thus, gradient of water chemical potential existing in nature between environments of different organs if sufficient source of energy for a plant.