After this new study, we must also talk about a new forest atlas and answer the question of how many trees there are in the world. And fortunately, the trees are more than previously thought, a total of 1,327 million hectares.
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New Technologies for Fine-Tuning
The study, carried out by the Food and Agriculture Organization of the United Nations (FAO), involved the participation of more than two hundred researchers from different organizations.
While the large and qualified participation was important, what was really distinctive was the possibility of having the aforementioned high-resolution images, collected by DigitalGlobe satellites, used by Google Maps, among other search engines.
This new technology marks a before and after for our purpose, since it has sensors that have a resolution of 25 centimeters, greatly facilitating the analysis. Or, to put it more appropriately, making it possible with the use of Collect Earth. A hitherto unprecedented opportunity, which FAO has not hesitated to take advantage of.
How many trees are there in the world? More than previously thought – New technologies make it possible to refine the data!
What is Collect Earth?
Collect Earth is a tool that allows to collect data through Google Earth, and then to analyze high-resolution satellite images for different purposes. This is how it has been possible to collect specific data, on this occasion the realization of regional forest inventories in lands that until now has been poorly inventoried.
Specifically, drylands, with the intention of improving the understanding of the elements present in them in order to deepen the knowledge of the resources available as well as to know what environmental protection needs exist.
The “Global Dryland Assessment” is actually a broader project, which also includes counting dryland grasslands through an assessment that uses Collect Earth to analyze more than 200,000 plots worldwide.
The objective of carrying out a global count of forest cover (including forests, trees, and grasslands) is achieved with a series of specific methodologies developed by FAO. As the study concludes, in 2015 there were 1,327 million hectares of arid climate biomes with a percentage of forest cover greater than 10 percent.
This data is important because it is the threshold FAO uses to use the designation of forest in an area of 5,000 square meters. But the main finding is the redefinition of the forest map of the drylands. In the words of Elena María Abraham, co-author of the study:
The important thing is that by identifying a larger area of dry forest, we are redrawing the map of drylands. Faced with a scenario of climate change and desertification, in which drylands are going to expand, it is crucial to know the dry forests, the most important resource we have.
Finally, FAO has carried out this analysis within the framework of two complementary projects of the same organization, such as “Action Against Desertification” and “Global Forest Survey”, whose implementation relies on the collaboration of a network of governments, NGOs, and academic institutions, among other collaborators.
In other words, beyond the good news of having a greater forest mass, the study has a practical purpose that seeks development in regions that, in general, have scarce resources.
Conclusions
Until now, we have ignored a tree cover that would occupy a total of 467 million hectares or, in other words, as many trees as those that make up the Amazon rainforest. This brings the global tree cover to 1,327 million hectares.
This update has been made possible by using high-resolution aerial images that improve the results provided by satellites such as Sentinel or Landsat. Above all, it has been refined when counting in arid regions, where trees do not form forests that are easy to translate into trees and, in short, in a given forested area, measured in hectares.
Dry areas, on the other hand, have more scattered trees. As they are not continuous green areas, counting is more complicated. And, according to the new data, the figures were significantly underestimated.
If we also take into account that almost half of the earth’s surface is characterized by this aridity, we have that the smaller number of trees found in this large space (specifically 41.5 percent of it) ends up adding up to a good number.
Although there may have been an idea of this deficiency at the time of counting, the technology needed to remedy it was not available, and, therefore, the environmental implications that this would entail could not be known concretely.
Now, things have changed and it has been possible to review the arid regions, counting the trees that were previously left out. This is the largest review of these arid regions to date for this purpose.
“Using very high-resolution images means that now each pixel of the satellite image can be much more specific and better detect the amount of forest,” explains Javier Gódar, a researcher at the Stockholm Environment Institute (SEI), who also emphasizes the importance of continuing to apply this technology for monitoring and follow-up. In this way, logically, it would be possible to have more reliable data on both reforestation and deforestation processes in these forgotten areas.
