NASA scientists developed the first-ever method for mapping the Earth's underground fungi network from space. The method is valuable to help scientists predict which forests will survive and which ones will falter in response to climate change.
The team studied images of four forest research plots in the United States, which are all part of the Smithsonian Institution's Forest Global Earth Observatory. In the past, scientists used traditional methods in creating maps of forests and their underground friends. This method, however, can't be used for large areas of land but the new method the scientists developed could cover massive land areas since it uses images taken from space.
This information could help shed light on how climate change will change forest habitats in the near future. Nearly all forest trees live with underground fungi, a relationship that is part of the ecosystem. This means that if one factor is severely altered by global warming, the whole ecosystem is affected.
The fungi, called mycorrhizal fungi, can spread for miles underground, looking for nutrients that trees need in exchange for the sugars made by trees during photosynthesis. The method, which allows scientists to predict how these organisms will respond to changes in the environment, could help in the study of forests, particularly in predicting which forests will thrive in the future and determining how they can be saved from damage.
Tree species may be linked to only one of the two kinds of mycorrhizal fungi. The two types react to the changes in climate differently. This information is important for scientists in predicting the survival rates of forests.
The scientists analyzed the images of the canopies taken by the U.S. Geological Survey Landsat-5 satellite between 2008 and 2011. The forests contain 130,000 trees spanning 77 species.
The scientists were able to determine the differences in the tree species and corresponded them to the two main types of fungi. Using a statistical model, they were able to correctly predict the areas in which fungi dominated in 77 percent of the Landsat images. They then created large-scale maps of the fungi associations to reveal patterns in forest canopies for future study.
"That these below-ground agents manifest themselves in changes in the forest canopies is significant. This allows, for the first time, some light to be shed on their hidden processes," said Joshua Fisher of NASA's Jet Propulsion Laboratory.
The study was published in the journal Global Change Biology.
Photo: Stiller Beobachter | Flickr
