What does primary productivity measure?
It is The rate at which phototropha make organic matter
The capacity of a forest to produce specific products (i.e. biomass, lumber) over time as influenced by the interaction of vegetative manipulation and abiotic factors (i.e. soil, climate, physiography). Net primary productivity (NPP) provides the fundamental measure of forest productivity. When measured at the point of foliar carrying capacity for all potential flora, NPP is a measure of potential site productivity. Rate of product growth, an economic component, is occasionally used as a partial measure…
The advantages of using GDP as a measure of productivity and economic health is that GDP is universal and can be used to measure an economy's growth or decline. The disadvantage of using GDP as a measure of productivity and economic health is that it does not effectively measure the quality of products.
Productivity is a measure of the efficiency of production. Productivity is a ratio of what is produced to what is required to produce it. Usually this ratio is in the form of an average, expressing the total output divided by the total input. Productivity is a measure of output from a production process, per unit of input.
Labour productivity is defined by the OECD to be "the ratio of a volume measure of output to a volume measure of input" OECD Manual: "Measuring Productivity; Measurement of Aggregate and Industry-Level Productivity Growth. Labour productivity is important to economic growth because without it no one would be working.