The respiration rate is a parameter which is used in ecological and agronomical modeling.
In theoretical production ecology

Theoretical production ecology

Theoretical production ecology tries to quantitatively study the growth of crops.The plant is treated as a kind of biological factory, which processes light, carbon dioxide, water and nutrients into harvestable parts....

 and aquaculture

Aquaculture

Aquaculture, also known as aquafarming, is the farming of aquatic organisms such as fish, crustaceans, molluscs and aquatic plants. Aquaculture involves cultivating freshwater and saltwater populations under controlled conditions, and can be contrasted with commercial fishing, which is the...

, it typically refers to respiration per unit of time (usually loss of biomass by respiration per unit of weight), also referred to as relative respiration rate. In theoretical production ecology, biomass is expressed as dry weight, in aquaculture as wet fish weight.
The respiration rate is dependent of species, type of tissue or organ studied and temperature.