World maps of climatological net primary production of biomass, NPP
Jürgen Grieser, René Gommes,
Stephen Cofield and Michele Bernardi
The Agromet Group, SDRN
FAO of the UN, Viale delle Terme di Caracalla,
00100 Rome, Italy
Contact: Agromet@fao.org or juergen.grieser@rms.com
August 2006
Introduction
In 1999, the FAO Environment and Natural Resources Service published
some global climate grids and various derived products like the agroclimatic
production potential according to Lieth (1972) and maps of Koeppen climate
classes (click
here for details).
Here we present updated versions of the global maps of net primary
production (NPP) based on the most recent gridded data sets of temperature and
precipitation (click here
for details). Updated maps of Koeppen climatology can be found here. The Map shows
NPP for the period 1951 to 2000 based on datasets from CRU and GPCP VASClimO. A
larger version of the map can be downloaded here.
For a short description of the net primary production according to the
model of Lieth (1972) which became famous as the Miami model click here.
We are providing NPP based on different data sets and for different
periods to allow users to assess the differences as a function of the data
source and period covered. As an example, a map of differences in mean NPP
between 1951-1975 and 1976-2000 is shown.
We are providing all data as tables of comma separated values for a
.5°x.5° grid with seven columns containing gridpoint number, longitude in .01
degrees, latitude in .01 degrees, land fraction of the grid cell in %, NPP, NPP
if precipitation were limiting (NPPP), NPP if temperature were
limiting (NPPT).
Comma separated value (csv) |
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All 1951 - 2000 |
Norm 1961 - 1990 |
Early 1951 - 1975 |
Late 1976 - 2000 |
CRU |
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GPCP Full |
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GPCP VASClimO |
The following high resolution maps of NPP (5’x5’) are available as
georeferenced IDA/Windisp grids only. Colour tables for the IDA images are here.
Georeferenced
Data |
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All 1951 - 2000 |
Norm 1961 - 1990 |
Early 1951 - 1975 |
Late 1976 - 2000 |
CRU |
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GPCP Full |
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GPCP VASClimO |
A map of the limiting factor (precipitation or temperature) is provided
here as IDA image and bitmap. It is based on the CRU and
VASClimO datasets.
Between the two periods pronounced differences in climatic npp appear in
some regions of the world. The following graph shows the latitudinal dependence
of these differences. It demonstrates that npp would have increased for most
latitudes if temperature were the limiting factor. However, especially between
0 and 20° North the npp decreased because of its precipitation dependency.
The latitudinal profiles are available for all datasets as comma
separated values. The files consist of 6 columns each, containing latitude belt
number, latitude in degrees, land area of the .5°-latitude belt in 1000 km2,
average npp of the latitude belt, npp if it where temperature limited, npp if it
where precipitation limited.
npp latitude profile as csv, all |
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All 1951 - 2000 |
Norm 1961 - 1990 |
Early 1951 - 1975 |
Late 1976 - 2000 |
CRU
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GPCP Full |
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GPCP VASClimO |
High resolution images of the differences in npp between 1951-1975 and
1976-2000 are provided for the CRU/VASClimO dataset as IDA image and bitmap.
According to the Miami model the sensitivity of NPP with respect to
changes in annual mean temperature dNPP/dT and annual mean precipitation
dNPP/dP can be calculated for each location on earth. Since for each location
NPP is either temperature limited or precipitation limited only one of the
sensitivities differ from zero.
Sensitivity of net primary production NPP in g(dry matter)/m2/year
with respect to changes in annual mean precipitation in mm/year. Red areas are
not sensitive to precipitation changes given the current temperatures. Download
this bmp (enlarged) or IDA image.
Sensitivity of net primary production NPP in g(dry matter)/m2/year
with respect to changes in annual mean temperature in °C. Light blue areas are
not sensitive to temperature changes given the current precipitation. Download
this bmp (enlarged) or IDA image.
Download this file as pdf.
Literature
Lieth, H., 1972.
"Modelling the primary productivity of the earth. Nature and
resources", UNESCO, VIII, 2:5-10.