Total amount of solar or geothermal energy converted to chemical energy in a certain time period by organisms in a given region. 863
the amount of carbon fixed in photosynthesis by plants
The total amount (mass or weight) of organic matter created by photosynthesis over a defined time period (total product of photosynthesis).
The amount of energy fixed by photosynthesis over a defined time period.
Primary production is the fixation of light energy into chemical compounds (the construction of sugars from CO2 and water; photosynthesis). Gross primary production then refers to the total amount of energy fixed by plants (the primary producers). This energy can then be used by plants to generate new biomass; growing.