Extending Species-Area Relationships Into the Realm of Ecoacoustics: The Soundscape-Area Relationship

The rise in species richness with area is one of the few ironclad ecological relationships. Yet, little is known about the spatial scaling of alternative dimensions of diversity. Here, we provide empirical evidence for a relationship between the richness of acoustic traits emanating from a landscape, or soundscape richness, and island area, which we term the SoundScape-Area Relationship (SSAR). We show a positive relationship between the gamma soundscape richness and island area. This relationship breaks down at the smallest spatial scales, indicating a small-island effect. Moreover, we demonstrate a positive spatial scaling of the plot-scale alpha soundscape richness, but not the beta soundscape turnover, suggesting a direct effect of species on acoustic trait diversity. We conclude that the general scaling of biodiversity can be extended into the realm of ecoacoustics, implying soundscape metrics are sensitive to fundamental ecological patterns and useful in disentangling their complex mechanistic drivers. In this study, we expanded the principles of island biogeography to the field of ecoacoustics. We examined the relative importance of island size and isolation in predicting the spectro-temporal richness of acoustic traits in the landscape, also known as soundscape richness. We provide evidence for a new ecological pattern showing a positive relationship between the soundscape richness and island size-which we term the SoundScape Area Relationship (SSAR).image