Answer:
In order to reach Net Primary Productivity, it is necessary to deduct from the Gross Primary Productivity the total organic matter that is consumed from a harvest field. So, we have to: <u>Net Primary Productivity (NP) = Gross Primary Productivity - organic matter consumed in the respiration process of the plants.</u>
Explanation:
The factors that influence the net and gross productivity of the ecosystem are: water, light, carbon dioxide and the available nutrients. The more sunlight the system receives, the greater the productivity. Thus, in tropical regions - where there is more sunlight and temperatures are higher throughout the year - productivity is higher than in places with a temperate, cold or polar climate.
It is estimated that 5% of sunlight is transformed into Gross Primary Productivity. The percentage transformed into Net Primary Productivity varies from 2.5% to 4%. For breathing, the plant takes advantage of 1% to 5% of solar energy. These data reveal that sunlight is not the only important factor for productivity: if there is no water in the place, as in deserts, productivity is low, as the soil does not offer conditions for the development of various species.
