Biomass ProductivityNet biomass productivity is the difference between gross productivity (production of plant material by photosynthesis) and respiration. So long as the rate of production exceeds that of respiration, the plant will grow. Net productivity represents the amount of organic material produced by a plant. Net productivity is closely related to a number of environmental factors like climate, soils, and available nutrients. Net biomass production will be highest where there is an ample supply of moisture to meet the needs of plants. Biomass productivity is also high where soils are rich in nutrients and have a positive soil moisture balance. The figure below illustrates this well. With ample rainfall and sunlight, the tropical rain forest ranks the highest in terms of organic matter production. Figure BE.6 Net productivity of selected environments |