Loss of urban forest canopy and the effects on neighborhood soundscapes

The urban landscape constitutes a key aspect of human - nature interactions, as more than 60% of the world’s population resides in cities and their suburbs. This study focuses on the characteristics of the landscape that humans (and other organisms) perceive as sound and the role of a suburban soundscape in defining experience of place. Vegetation plays an important role in shaping soundscapes, both by creating sound and attenuating sound from natural and human sources. An invasive insect pest, the Emerald Ash Borer (Agrilus planipennis), is killing millions of ash trees (genus Fraxinus) throughout North America. As a result, many municipalities are systematically removing Fraxinus trees. The objective of this research was to determine if and how removal of a substantial amount of the urban forest in such a community causes changes in the local soundscape, particularly in the proportion of human-sourced sounds versus sounds associated with nature. We selected Arlington Heights, Illinois, as the study site, where a series of before-and-after sound recordings were gathered as ash trees were removed between 2013 and 2015. Comparison of recordings using the Raven sound analysis program revealed significant differences in some measures of sound attributes tested as tree canopy decreased. We detected more human-produced mechanical sounds (anthrophony) and fewer sounds associated with weather (geophony) in these sites. Changes in sounds associated with animals (biophony) varied seasonally. We conclude that monitoring changes in the proportions of anthrophony, biophony and geophony provides insight into fauna biodiversity and the human experience of a suburban ecosystem.