Interrelation between the vegetation index and the climatic parameters and structural characteristics of vegetation cover

The interrelations between the normalized difference vegetation index and the total incoming radiation; total evaporation; mean surface-air temperature over the vegetation period; and the structural characteristics of vegetation cover, such as its overground phytomass and overground net primary production, are analyzed on the basis of experimental and satellite data. The analysis was made with the use of the data obtained for plain regions of European Russia and western Siberia. It is shown that, for these regions, the latitudinal distributions of the values of the vegetation index and the structural vegetation-cover characteristics under consideration do not coincide. The relationships between the structural characteristics of vegetation cover (phytomass, production) and the vegetation index have the form of functions with saturation. The relationships between the vegetation index and the climatic parameters under consideration have a bell-shaped form. The analysis has shown that the normalized difference vegetation index is not an indicator for the values of the overground net primary production of vegetation cover and its overground phytomass within the areas under consideration.