== 3.17 Primary production ==

For primary producers the production is estimated as a function of the producers’ biomass, Bi, from a simple saturating relationship

[[Image(wiki:EwEug:08000039.png)]] '''Eq. 67'''

where, ''r,,i,,'' is the maximum production/biomass ratio that can be realized (for low ''B,,i,,''’s), and ''r,,i,,/h,,i,,'' is the maximum net primary production when the biomass is not limiting to production (high'' B,,i,,''’s). For parameterization it is only necessary to provide an estimate of ''r'',,''i'',, / (''P,,i,,/B,,i,,''), i.e., a factor expressing how much primary production can be increased compared to the base model state. If a [[Forcing function.htm|Forcing function]] is applied to primary production (see [[Apply forcing function primary.htm|Apply FF (primary producer]]), it multiplies the r parameter in Eq. 67.