To fill an evident information gap on land cover change processes associated to tropical deforestation, and to complement the heterogeneous mass of existing country data, FAO carried out, during FRA 1990, the first pan-tropical survey based on high resolution remote sensing data. The survey was based on 117 sampling units covering ten percent of the survey area, each unit composed by multi-date Landsat MSS and TM data representing the period 1980-1990.
In the framework of the remote sensing component of FRA 2000 the 117 sampling units are now being revisited with most recent satellite acquisitions, and following the same methodological approach. This new survey, called Tropical 2000 Update, has the purpose of estimating deforestation rates and studying the land cover change processes of the current decade as well as carrying out an unprecedented assessment of trends comparing current rates and processes to those of the previous decade.
Beyond FRA 2000 and the forthcoming appointment with the millennium, in response to the call for frequent, consistent and thematically deeper information, FAO is developing an expanded survey concept called World Forest Survey. This proposed survey is intended as an extension and intensification of the remote sensing survey currently carried out. Main new features are the extension of the survey to the entire world, the use of a new survey design benefiting from the information produced by the current pan-tropical survey, and the development of a consistent field component for the collection of forestry, environmental and socio-economic parameters.
