According to Whittaker (1975) of the three ecosystems, algal beds and reefs have the highest average primary productivity of 2500 g m-2y-1. Esturies are also fairly productive areas, averaging 1500 g m-2y-1. The open ocean on the other hand is a relatively unproductive system, averaging 125 g m-2y-1.
However, if you look at the total productivity, and not the averages, the picture changes substantially. Now the open ocean contributes the most to the total global productivity due to vastly greater area than either esturies or algal beds and reefs. Indeed, with just 1.2 x 109t-1 algal beds and reefs contribute the least to the total global productivity.
It is also worth noting that continental shelf areas have a higher productivity than open ocean, but contribute less to the global total, again because of reduced area.
All figures taken from
Whittaker RH (1975) Communities and Ecosystems. London, Collier-Macmillan cited in Tivy J (1993) Biogeography A Study of Plants in the Ecosphere. Longman Scientific & Technical
The rate at which the ecosystem produces chemical energy from sunlight.
Primary productivity tells you how productive an ecosystem will be. It is the rate at which chemical energy is produced from sunlight, which determines the maximum amount of energy available to all higher trophic levels in an ecosystem.
Gross
Net primary productivity is the amount of energy that remains in an ecosystem after accounting for the energy used by producers (plants) for respiration. It is calculated by subtracting the respiration rate of producers from the gross primary productivity. This remaining energy is available for consumers in the ecosystem to use for growth and reproduction.
The oxygen in the atmosphere is primarily derived from plant respiration
An example of gross primary productivity in an ecosystem is the process of photosynthesis in plants, where they convert sunlight into energy to produce food for themselves.
The rate at which the ecosystem produces chemical energy from sunlight.
Primary productivity tells you how productive an ecosystem will be. It is the rate at which chemical energy is produced from sunlight, which determines the maximum amount of energy available to all higher trophic levels in an ecosystem.
The gross primary productivity formula is: Gross Primary Productivity Rate of Photosynthesis - Rate of Respiration. This formula calculates the amount of energy produced by plants through photosynthesis in an ecosystem.
The amount of organic material that autotrophic organisms produce in an ecosystem is known as primary production. This is the process by which plants, algae, and photosynthetic bacteria convert sunlight into energy through photosynthesis, creating organic compounds that form the base of the food chain. Primary production is essential for providing energy to the rest of the ecosystem.
Gross
Primary productivity in an ecosystem is typically measured by calculating the amount of energy or biomass produced by plants through photosynthesis. This can be done by measuring the rate of oxygen production, tracking the growth of plant biomass, or using remote sensing techniques to estimate plant productivity.
Net primary productivity is the amount of energy that remains in an ecosystem after accounting for the energy used by producers (plants) for respiration. It is calculated by subtracting the respiration rate of producers from the gross primary productivity. This remaining energy is available for consumers in the ecosystem to use for growth and reproduction.
After gross primary productivity (GPP) occurs in an ecosystem, energy is lost through processes such as respiration, heat loss, and consumption by other organisms. This results in a decrease in the amount of energy available for further growth and development within the ecosystem.
Ruben Lara-Lara has written: 'Primary biomass and production processes in the Columbia River estuary' -- subject(s): Primary productivity (Biology)
Secondary consumers
The oxygen in the atmosphere is primarily derived from plant respiration