ECONOMIC-MODEL OF A PLANT - A GENERAL-APPROACH

An economic model for describing a whole plant is suggested. The prima ry assumption in reconstructing the costs of a plant is based on the b elief that its actually observed life activity is optimal. The life ac tivity of the plant is considered from the hierarchy of its costs. An optimization principle is chosen at each level of the hierarchy; the p rinciple implies that maximal efficiency of material and energy costs takes place. It is suggested that the decrease in efficiency (in terms of material and energy costs) can be considered as a criterion for de viation from the optimal state. The process of photosynthesis was pref erred to start the economic description of a plant because the costs a nd resulting product can be expressed in the same units. It was sugges ted that the total plant costs be separated into two isolated groups: water transport and reproduction of the photosynthetic apparatus (in t he broad sense of the term, from a microscopic to organismic level). T he developed approach is promising for identifying the interrelations between all the diverse physiological processes in plants (photosynthe sis, water exchange, translocation of assimilates, etc.).