A new Yale-led study estimates that there are more than 3 trillion trees on Earth, about eight times more than some previous estimates. But the total number of trees has plummeted by roughly 46% since the start of human civilization, the study estimates.
Using a combination of satellite imagery, forest inventories, and supercomputer technologies, the international team of researchers was able to map tree populations worldwide at the square-kilometer level.
Their results, published in the journal Nature, provide the most comprehensive assessment of tree populations ever produced and offer new insights into a class of organism that helps shape most terrestrial biomes.
The new insights can improve the modeling of many large-scale systems, from carbon cycling and climate change models to the distribution of animal and plant species, say the researchers.
The Swiss Federal Institute for Forest, Snow and Landscape Research WSL contributed to the study with data from the National Forest Inventory.
This is an excerpt from the official press release of the Yale School of Forestry & Environmental Studies. You may read the full text and find additional information on the Yale website.
Scientific publication
Thomas Crowther et al. "Mapping tree density at a global scale”, Nature, Advance Online Publication, 02.09.2015, http://dx.doi.org/10.1038/nature14967