In the equation GPP – R = NPP. GPP is Gross Primary Productivity NPP is Net Primary Productivity R here is __________.

In the equation GPP – R = NPP. R represents respiratory losses. In the equation GPP - R = NPP: GPP refers to gross primary productivity, which represents the total amount of energy captured by plants through photosynthesis. NPP stands for net primary productivity, which represents the energy remaining after plants have utilised some of the energy for their own metabolic processes. Therefore, in this equation, R represents respiratory loss, which refers to the energy expended by plants during respiration or metabolic processes. It represents the energy used by plants for maintenance, growth, and reproduction.
(1) Reproductive allocation refers to the allocation of resources by an organism towards reproduction. The variable R in the equation GPP - R = NPP represents respiration but not reproduction.
(2) Photosynthetically active radiation (PAR) refers to the portion of the electromagnetic spectrum that plants
can use for photosynthesis. It is not represented by the variable R in the given equation.
(3) The respiratory quotient (RQ) is a measure of the ratio of carbon dioxide produced to oxygen consumed during cellular respiration. It is used to assess the type of fuel being metabolized (e.g., carbohydrates, fats). RQ is not represented by the variable R in the given equation.