Annual plant production and total plant mass are calculated for 106 types of soil and plant formations of the world, grouped in turn by major thermal belts and bioclimatic regions (humid, semiarid, arid) within these thermal belts. Aggregate magnitudes of annual growth and total plant mass by thermal belts and their bioclimatic regions follow a sequence of alternating high values in humid regions and low values in arid regions that bears a similarity to the periodic law of geographical zonality. Maximum plant production is associated with the Tropical belt, where combinations of heat and moisture favor maximum intensity of the physical-geographic process. A related paper, by Bazilevich and Rodin, appeared in Soviet Geography, January 1971.