A new survey of the world’s dryland habitats has found a massive amount of previously unreported forests — 467 million hectares (over 1.1 billion acres), which is 45 percent more forest than found in past surveys. The newly discovered dryland forests cover an area equivalent to 60 percent of the size of Australia, putting dryland forest extent on par with tropical rainforests and boreal forests. The discovery could be good news for reversing global warming as it increases the estimates of total global forest carbon stocks by 15 gigatons to 158 gigatons — an increase of 2 percent to 20 percent.
Although dryland biomes occupy more than 40 percent of the Earth’s land surface, these forests were previously difficult to spot because of the relatively low density of the trees. Technological advances have made it easier to accurately measure dryland forests as demonstrated in this survey. The scientists used Google Earth Engine to analyze high-resolution satellite images of more than 210,000 dryland sites in order to determine tree number and density. The researchers then compared samples of their findings with field information for accuracy.
The study’s authors point out the importance of understanding dryland forests and dryland ecosystems because climate modeling suggests these biomes could expand by 11 percent to 23 percent by the end of the century, covering more than half of the Earth’s land surface.
“Considering the potential of dryland forests to stave off desertification and to fight climate change by storing carbon, it will be crucial to keep monitoring the health of these forests, now that we know they are there,” said University of Adelaide School of Biological Sciences professors Andrew Lowe and Ben Sparrow, co-authors of the study.
Images via TERN AusPlots