Each interaction in a food chain when energy is transferred from a consumed organism to a consumer organism is called a trophic level.
Primary producers are autotrophic organisms that generate organic materials. Primary consumers, which are organisms that cannot make their organic materials, consume primary producers. However, primary consumers can be sources of energy to others that are secondary consumers.
Organic material stored in an organism is called the biomass and excludes the water contained by the organism.
Productivity is the rate at which organisms gain biomass from received energy. Productivity of primary producers is called primary productivity and of others is called secondary productivity. They can be further categorized into two forms: gross and net. For instance, gross primary productivity is the rate at which photosynthesis or chemosynthesis occurs, while net primary productivity is the rate at which energy is stored as biomass in these organisms.
Organisms in an ecosystem depend on resources they consume and are connected by the flow of energy and matter from one another. Changes in the balance can have detrimental effects to other organisms in the food chain, including humans. Understanding energy dynamics can help find solutions to mitigate negative effects of changes in the ecosystems, such as keeping populations under control or preventing secondary extinctions.