Question

Which one of the following is the most productive ecosystem?
(А) Temperature forest
(B) Grassland
(C) Desert
(D) Tropical rainforest

Answer 1

Ecosystem is defined as a biological community that remains integrated with its physical environment through the exchange of energy and recycling of nutrients. Regional and local variations within each biome leads to the formation of a wide variety of habitats .

Complete answer:
The main aspect of the ecosystem includes productivity.
Primary Productivity: It is the rate at which biomass or organic matter is produced by plants or producers during photosynthesis per unit area over a time period or it refers to the rate at which sunlight is captured by producers for the synthesis of energy-rich organic compounds through photosynthesis. Gross Primary Productivity (GPP): Rate of production or synthesis of organic matter by producers during photosynthesis per unit time. Net Primary Productivity (NPP) : Gross primary productivity minus respiratory losses. The most stable ecosystem is one that has high net primary productivity.
Temperature forest: These forests have so much respiratory loss. They do not have a large amount of biomass for heterotrophs. Thus, they are not a stable ecosystem.
Grassland: This type of ecosystem does not build up a large amount of organic matter so they have low NPP. Thus, they are not a stable ecosystem.
Desert :- this ecosystem has very low availability of nutrients so this is the reason they have very low net primary productivity. So, it is not a stable ecosystem.
Tropical rainforest :- this forest has high soil moisture , high availability of nutrients so it has high net primary productivity. Hence, they are the most stable ecosystem.

Our required answer is tropical rainforest.

Note: net primary productivity is the rate of organic matter built up or stored by producers in excess of respiratory utilization per unit time and area.
NPP=GPP-R
Net primary productivity is the available biomass for the consumption of heterotrophs.