Mathematically, the biomass in the ocean contributes times more grams of npp per year per gram than an equivalent gram of plant biomass in a terrestrial ecosystem.

Answer;

-Over 4000

Mathematically, the biomass in the ocean contributes over 4000 times more grams of NPP per year per gram than an equivalent gram of plant biomass in a terrestrial ecosystem.

Explanation;

-Living biomass forms a tiny fraction of Total Ocean carbon but has a very significant influence on the ocean carbon cycle. Every gram of biomass of the primary producers in the ocean contributes more to NPP per year than plant biomass of terrestrial ecosystems.

-In marine ecosystems, phytoplankton is the main source of primary production. The nutrient availability cycles make it important to distinguish between new and regenerated primary production ; the former identifies the annually renewed nitrogen, while the second measures the rapid cycling of nitrogen through ammonia availability.

the answer is:

carbon dioxide