John Pozzi wrote:.Rear money,

.Rear money, i.e., GRB ecos, signify the universal value of the product of nature, i.e., the generation of biomass in an ecosystem, usually expressed in units of mass per unit surface (or volume) per unit time, for instance, grams per square metre per day (g m−2 d−1). The mass unit may relate to dry matter or to the mass of carbon generated. Productivity of autotrophs such as plants is called primary natural productivity, while that of heterotrophs such as animals is called secondary productivity.Secondary production is the generation of biomass of heterotrophic (consumer) organisms in a system. This is driven by the transfer of organic material between trophic levels, and represents the quantity of new tissue created through the use of assimilated food that everyone consumes.