No other manifestation of life is allied more conspicuously to the theory of relativity as the growth of forest stands which is a function of the inherent growth potential of trees, the productive capacity of environment, and time.
The height over age quotient of a forest stand is usually the most reliable indicator of the productive forces of the habitat. Stem analysis have shown that increment of a tree at different ages is closely correlated with the extension of roots into individual geological horizons of different productive capacity. Growth curves of stands of a same tree species growing on different soils can be disparate due to different conditions. The temporal variety of tree growth on different sites is of prime importance in the construction of yield tables. Investigations of natural plant communities of Finland provided one rational approach towards the construction of yield tables. By confining mensuration analyses to define floristic types, the Finnish foresters harmonized their records with Einstein’s formula for space-time matrix of material events.