IIASA's Global Forest Database (GFD) contains information about the growing stock, biomass, and carbon stock in forests for 229 countries and territories at a half-degree global spatial scale. The information was downscaled from the Global Forest Resources Assessment (FRA), which was produced by the Food and Agriculture Organization (FAO) in 2005.
The IIASA GFD was one of the first attempts to produce a consistent global spatial database at a half-degree resolution. It provides forest growing stock; above/below-ground biomass, dead wood and total forest biomass; and above/below-ground, dead wood, litter, and soil carbon.
The downscaling method is derived using a relationship between net primary productivity (NPP) and biomass and the relationship between human impact and biomass, assuming a decrease in biomass with an increased level of human activity. As the number of countries providing data is incomplete, values for countries with missing data were estimated using regression equations based on a downscaling model.
The GFD will produce maps that are useful for current applications related to biomass burning emissions, carbon cycle, or deforestation issues.
The significance of forest area as a single indicator of forest development has often been overemphasized; growing stock, biomass, and carbon storage may be considered as equally important parameters.
Tropical forests account for 50% of Earth's total plant biomass. Knowing the spatial distribution of forest biomass is important for many reasons, for instance, to calculate the sources and sinks of carbon that result from converting a forest to cleared land (and vice versa), and to enable the measurement of change over time.
In 2008 when the GFD was released, information on global biomass distribution was either missing, relatively old, too general, or still under development. The FRA, which provides average biomass values per country, is still one of the most important global maps available. However, for use in spatially explicit analysis and modeling being undertaken at IIASA, this information was required at a finer level of detail than country level. Moreover, many countries had difficulties in providing data for the FRA, creating gaps that were preventing a truly global analysis.
Currently the datasets that can be used to validate GFD results are sparse, but with sub-national statistics from FAO becoming available, the methodology could be improved.
As the Earth science community is eager to use global higher resolution datasets, the latter are made available for use in a number of applications. However, it is recommended that users of these datasets be aware of the current limitations and shortcomings and the data should be used with care.
Last edited: 22 April 2013
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