Primary producers

From Wikipedia, the free encyclopedia
Jump to: navigation, search
The leaf is the primary site of photosynthesis in plants.

Primary producers are organisms in an ecosystem that produce biomass from inorganic compounds (autotrophs). In almost all cases these are photosynthetically active organisms (plants, cyanobacteria, protists and a number of other unicellular organisms; see article on photosynthesis). However, there are examples of archaea and bacteria (unicellular organisms) that produce biomass from the oxidation of inorganic chemical compounds (chemoautotrophs) in hydrothermal vents in the deep ocean. These organisms are considered to exist at the lowest trophic level.[1]

Fungi and other organisms that gain their biomass from oxidizing organic materials are called decomposers and are not primary producers. However, lichens located in tundra climates are an exceptional example of a primary producer that, by mutualistic symbiosis, combine photosynthesis by algae (or additionally nitrogen fixation by cyanobacteria) with the protection of a decomposer fungus.


  1. ^ Post, David M. (March 2002). "USING STABLE ISOTOPES TO ESTIMATE TROPHIC POSITION: MODELS, METHODS, AND ASSUMPTIONS". Ecology. 83 (3): 703–718. doi:10.1890/0012-9658(2002)083[0703:USITET]2.0.CO;2. 

External links[edit]