The FAO has along with Google developed an economically feasible way of assessing trees, forests, land use and land-use change in any area of the world. The preliminary report of the first Global Drylands Assessment by FAO provides a baseline for monitoring and help in identifying priority intervention areas for land restoration.
The full report also endeavours to make available data and information public through a web-based data portal under a common creative licence. The report notes that “drylands cover about 41 percent of the Earth’s land surface and are characterized by a scarcity of water. About 90 percent of the estimated 2 billion people living in drylands are in developing countries. The majority of these people depend on forests and other wooded lands, grasslands and trees on farms to meet basic needs for food, medicines, shelter, cooking, heating, wood, and fodder for livestock, and for income”.
Trees and forests in drylands generate a wealth of environmental services, the report says thereby necessitating the need to assess changes in them. Further, “life in the drylands is precarious, and the socioeconomic status of people in drylands is significantly lower than that of people in many other areas… Challenges such as land degradation and desertification, combined with drought, hunger and violence, are already leading to forced migration in dryland regions,” the report highlights.
As per the report “the management and restoration of drylands requires a comprehensive understanding of the complexity, status and roles of drylands, as well as context-specific approaches tailored to the unique conditions of drylands. But dryland forests and other ecosystems have not attracted the same level of interest and investment as other ecosystems, such as humid tropical forests. Tree cover and land use in drylands are poorly known, even though recent studies have indicated the need to restore drylands to cope with the effects of drought, desertification, land degradation and climate change”.
This report is based on the visual interpretation of satellite images in publicly available repositories (such as Google Earth Engine and Bing Maps), and it focuses solely on drylands. The results, therefore, are reported at the global and regional levels, not the country level. The methodology involved assigning of a predominant land use to each sample plot based on the presence of key land-use indicators interpreted according to a hierarchical rule.
The report is one of the first to underline the fact that “trees are an important part of the vegetation in drylands, and they grow both in and outside forests. Trees in drylands protect soils, crops and animals from sun and wind… Until now, there has been little statistically based knowledge on the extent of trees in drylands, particularly those growing outside forests. This is a significant gap because the health and future of trees is crucial for the livelihoods and well-being of millions of people living in drylands”. New information on trees in drylands is presented in the report.
The full report can be accessed at FAO here