Posted by Nathaniel Hardy on Thu, Mar 02, 2017 @ 7:46 AM
Trees can be deceiving – while they may look healthy from the outside, inside often tells a very different story. Wood rot in living trees causes overestimates of global carbon pools, timber loss in forestry, and poor tree health. Wood decay is of particular concern in the tropics, with tropical forests estimated to harbor, “96% of the world’s tree diversity and about 25% of terrestrial carbon, compared to the roughly 10% of carbon held in temperate forests.”
But how can foresters and researchers see into a living tree to measure wood decay? Surprisingly, with sound. A recently published article in Applications in Plant Sciences details methods using a sound wave technology called sonic tomography, tested on more than 1800 living trees in the Republic of Panama.
Greg Gilbert, lead author of the article and Professor and Chair of the Department of Environmental Studies at the University of California, Santa Cruz, said, “We don’t yet know where internal decay and damage rank as a cause of tree mortality. Most of the decay is hidden–the tomography now allows us to see how many apparently healthy trees are actually decayed inside.”
Sonic tomography sends sound waves through tree trunks, with the longer it takes for a sound wave to traverse a trunk indicating more decay in the wood. Based on the velocity of sound, the tomograph makes a color-coded image of a cross section of the trunk.
Sonic tomography can also be used for urban forestry. In fact, Gilbert and his colleagues, together with the Smithsonian Tropical Research Institute will collaborate with Panama City to use tomography to evaluate the health and associated risks of Panama’s urban trees.
Learn more about innovative tree solutions for urban forests here.