Net Primary Productivity Methods
Net Primary Productivity Methods
NPP Defined

Net primary productivity (NPP) is defined as the net flux of carbon from the atmosphere into green plants per unit time. NPP refers to a rate process, i.e., the amount of vegetable matter produced (net primary production) per day, week, or year. However, the terms net primary productivity and net primary production are sometimes used rather liberally and interchangeably, and some scientists still tend to confuse productivity with standing biomass or standing crop. NPP is a fundamental ecological variable, not only because it measures the energy input to the biosphere and terrestrial carbon dioxide assimilation, but also because of its significance in indicating the condition of the land surface area and status of a wide range of ecological processes.

Estimating NPP

There are many ways to estimate terrestrial NPP from field measurements that depend on the type of plants and available measurements. Methods are discussed in connection with the biomes included in the NPP Database. Some of the methodology reviews were carried out as part of the NCEAS (National Center for Ecological Analysis and Synthesis) Working Groups on "Development of a Consistent Worldwide Net Primary Production (NPP) Database" between December 1997 and October 1998.

  • Grasslands - technical discussion of estimation algorithms
  • Boreal Forests - link to the NCEAS group that summarized NPP methods and data available for boreal forests
  • Tropical Forests - link to the NCEAS group that summarized NPP methods and data available for tropical forests