Issues of energy index modeling of vegetation phenology

The article is devoted to energy index modeling of vegetation phenology. Based on the dual sigmoidal model representation of the phenological cycle, an energy-index approach to phasing the stages of vegetation development and deactivation is proposed. The optimal laws for changing the amplitude of the model in the phases of development and decontamination have been determined, at which the energy released by vegetation into the environment can reach a maximum. The relationship between the LAI index and the phenological state of vegetation has been investigated. The study of the relationship of LAI with another phenological indicator of vegetation, in particular the prognostic phenological state of vegetation P . It is shown that despite the inverse logarithmic relationship between LAI and FPAR, and also due to the direct dependence of P and FPAR, averaged over all possible values of f v, the value of P increases in the presence of a direct relationship between LAI and f v.