Maximal net primary production near the equator

Value ~1.6 Pg of Carbon/degree of latitude
Organism Biosphere
Reference Field CB, Behrenfeld MJ, Randerson JT, Falkowski P. Primary production of the biosphere: integrating terrestrial and oceanic components. Science. 1998 Jul 10281(5374):pp. 238 and fig. 2APubMed ID9657713
Method Carnegie-Ames-Stanford approach (CASA) for land and the Vertically Generalized Production Model (VGPM) for the oceans. Calculated from long term global measurements from satellites according to model integrated from 3 equations: (1) NPP=APARXepsilon. APAR-Absorbed Phosynthetically Active solar Radiation. epsilon-effective photon yield for growth. (2) NPP=f(NDVI)XPAR3Xepsilon*Xg(T)Xh(W). NDVI-normalized difference vegetation index. PAR-downwelling Phosynthetically Active solar Radiation. epsilon-as in (1), adjusted by functions that account for effects of temperature g(T) and water h(W) stress. equation (3) NPP=CsatXZeuXf(PAR)XPb,opt(T) where Csat is the satellite-derived, near-surface phytoplankton chlorophyll concentration (in milligrams per cubic meter), Zeu is the depth (in meters) to which light is sufficient to support positive NPP, f(PAR) describes the fraction of the water column from the surface to Zeu in which photosynthesis is light saturated, and Pb,opt(T) is the maximum, chlorophyll-specific carbon fixation rate (in milligrams of C per milligram of chlorophyll per day), estimated as a function of sea-surface temperature.
Comments Pg=Petagram, 10^15 grams
Entered by Uri M
ID 102952