Sound plays an important role in the functioning of ecosystems, but has been little studied so far. The vast majority of studies focus on the effect of human sounds on animal behavior, or the function of animal sounds themselves. However, the range of acoustic patterns produced by an ecosystem also tells us a lot about the biological and physiological processes occurring there, such as the advancement of non-native plant species.
They are primarily animals that produce sound. But in an ecosystem all elements are intertwined, and this can be read in the acoustic patterns. Changes in vegetation composition have an impact on the diversity and abundance of animals, and thus on the soundscape, says researcher Gabrielle Ripa (Virginia Tech, USA). She and some colleagues investigated how non-native plants affect ecosystem sound.
“Invasive plants can reduce the numbers and diversity of animal species that make sounds,” Ripa says. “For example, if they replace native plants, that also has consequences for the insects that live on those plants. The opposite also happens. In this case, the presence of non-native plants is actually a positive thing for the animal species, and the noise in the system increases.” Environmental indeed.
Long listening
“Invasive plants can also affect the behavior of animals, and therefore the sound they make as well. Finally, non-native plants happen to change the physical properties of the ecosystem in a way that affects how sound propagates. We see this, for example, in the southeastern United States , where kudzu is a big problem. This climbing plant, originally from Japan, reproduces to the point that it effectively muffles sounds and makes ecosystems quieter.
Systematically listening to an ecosystem is not only interesting from a scientific point of view, but can also help nature managers monitor changes in the composition of fauna and flora. “In combination with research in this area, long-term acoustic monitoring can provide valuable information about invasive species and other processes that might otherwise remain out of sight.”
