Please forward this error screen to dprhcp159. The mass can be biomass conversion process pdf as the average mass per unit area, or as the total mass in the community.
How biomass is measured depends on why it is being measured. For other purposes, only biological tissues count, and teeth, bones and shells are excluded. The primary producers take energy from the environment in the form of sunlight or inorganic chemicals and use it to create energy-rich molecules such as carbohydrates. When energy is transferred from one trophic level to the next, typically only ten percent is used to build new biomass. The remaining ninety percent goes to metabolic processes or is dissipated as heat. This energy loss means that productivity pyramids are never inverted, and generally limits food chains to about six levels. However, in oceans, biomass pyramids can be wholly or partially inverted, with more biomass at higher levels.
In a temperate grassland, grasses and other plants are the primary producers at the bottom of the pyramid. Then come the primary consumers, such as grasshoppers, voles and bison, followed by the secondary consumers, shrews, hawks and small cats. Finally the tertiary consumers, large cats and wolves. The biomass pyramid decreases markedly at each higher level. Ocean or marine biomass, in a reversal of terrestrial biomass, can increase at higher trophic levels. They are then consumed by microscopic animals called zooplankton.