Organic soils and peatlands in particular have high influence on climate change and on the global carbon cycle. Indeed, the cultivation of organic soils entails drainage which causes significant release of CO2 in the atmosphere. Detailed information on regional and global emission trends of these soils is however scarce, due to the difficulty to map, measure and assess the complex dynamics of land, soil and water interactions that are required for a correct understanding of the degradation of organic soils caused by human activity. A geospatial analysis of drained organic soils and associated greenhouse gas emissions (GHG) were undertaken as part of the FAOSTAT global database of emissions for the Agriculture, Forestry and Other Land Use AFOLU sector. The database was first published in FAOSTAT in 2012 and it is updated yearly (FAO, 2016). Emissions estimates are derived from emission factors as reported in the 2006 IPCC guidelines and from activity data, namely the spatial distribution of organic soils and the spatial distribution of cropland on organic soils.
This metadata accompanies the public distribution of the layers applied for this spatial analysis. The geographical distribution of organic soils was derived from the Harmonized World Soil Database (HWSD v 1.2)(Nachtergaele et al., 2012). The HWSD v 1.2 dataset was queried to extract all pixels with any share of histosols, either as dominant or secondary soil type and to derive a map of the area of organic soils. The total area covered by the histosols worldwide resulted to be approximately 330 million hectares, a figure consistent with previous estimates. The land cover layer GLC2000 (Barthomé and Belward, 2005) was the source for cropland distribution.
More information can be found in:
a) Tubiello F.N., Biancalani R., Salvatore M., Rossi S., Conchedda, G., 2016. A Worldwide Assessment of Greenhouse Gas Emissions from Drained Organic Soils. Sustainability 8(4), 371; http://dx.doi.org/10.3390/su8040371.
b) Contribution of drained organic soils to GHG emissions in Towards climate-responsible peatlands management (Biancalani R., Salvatore M. and F.N. Tubiello), FAO, Rome, 2014. Page 12-14.
References:
1) Nachtergaele, F. O.; van Velthuizen, H.; Verelst, L.; Wiberg, D. Harmonized World Soil Database v 1.2; FAO/IIASA/ISRIC/ISS - CAS/JRC: FAO, Rome, Italy and IIASA, Laxenburg, Austria, 2012.
2) Bartholomé, E.; Belward, A. S. GLC2000: a new approach to global land cover mapping from Earth observation data. Int. J. Remote Sens. 2005, 26 (9), 1959–1977.
3) FAO, 2016. FAOSTAT Emissions database.
Acknowledgements: These spatial layers were produced as part of a large interdisciplinary activity across technical divisions of FAO, under the leadership of the Climate and Environment Division and the Statistics Division, within the project "Monitoring and Assessment of GHG Emissions in Agriculture". Generous funding was provided by the Governments of Germany and Norway, GCP/GLO/286/GER and GCP/GLO/325/NOR.
Contact points:
Metadata Contact: FAOSTAT
Resource Contact: Francesco Nicola Tubiello
Resource Contact: Riccardo Biancalani
Resource Contact: Giulia Conchedda
Resource Contact: Mirella Salvatore
Resource constraints:
FAOSTAT data and these datasets are part of FAO corporate statistical databases in scope of the FAO Open Data Licensing Policy. Terms of use are available at: http://www.fao.org/contact-us/terms/db-terms-of-use/en
Online resources:
Download: The compressed file histoshare.zip contains a GeoTiff (geographic projection - 0.00833333 cell resolution). Pixel values represent the share of organic soils (histosols)(percentage of pixel area).
Download: The compressed folder share_hist_crop_grass.zip contains 2 separate raster file in GeoTiff format (geographic projection - 0.00833333 cell resolution). 1) Pixel values represent the share of cultivated land in organic soils (histosols)(percentage of the pixel area); 2) Pixel values represent the share of the area of grassland cover in organic soil (histosols)(percentage of the pixel area).
Download: The compressed file Area_grid.zip contains a Geotiff raster image (geographic projection - 0.00833333 cell resolution). Pixel values represent the area of each pixel (values correspond to sqkm * 10,000. The file can be used to calculate the area of organic soils and the area of cultivated organic soils in each pixel.
