The movements of organisms like worms in the soil create distinctive sound patterns Vitalii Stock/Shutterstock It may not have the appeal of a dawn chorus of birds, but the noises of ants , beetle larvae and worms recorded below ground can provide a snapshot of whether an ecosystem is healthy. “The idea is that we can monitor soil health from the sounds the invertebrates are making,” says Jake Robinson at Flinders University in Adelaide, Australia. He and his colleagues chose six locations at Mount Bold reserve , a 55-square-kilometre area around a reservoir south of Adelaide, to make 240 recordings over five days in spring 2023, each lasting for 9 minutes.
Two sites had been cleared of trees about 15 years earlier and were being kept as grassland, two had been cleared but trees and bushes had been growing back for about 15 years, and two were undisturbed grassy woodland. Robinson and his colleagues also dug up soil samples at each location and put them in containers, which they placed in sound attenuation chambers, devices that allowed the noises from the soil to be recorded in controlled conditions with other sounds excluded. Then the researchers worked through the soil samples to count the type and number of invertebrates in each.
Jake Robinson (left) and his colleagues listening to noises in the soil Traci Klarenbeek They found that undisturbed and revegetated plots had more soil invertebrate species, including organisms such as beetle larvae, worms, centipedes, woodl.