Soundscapes as a surrogate measure of vegetation condition for biodiversity values: A pilot study

摘要

Environmental practitioners must conduct and monitor the effects of environmental management activities on ecosystem health with limited resources. Using soundscapes to monitor aspects of ecosystem health is a potentially economical, low impact alternative to traditional monitoring techniques. The success of using soundscapes as an alternative monitoring technique relies on developing a method that links soundscapes to the impact of resource management on biodiversity over time.We completed a pilot study to test whether soundscapes can be related to vegetation condition by comparing eight published soundscape metrics to BioCondition scores within a rural property in Queensland, Australia. Three-minute soundscape recordings and BioCondition score data were sampled within three broad vegetation conditions of a woodland ecosystem: cleared, regrowth and remnant. Our hypotheses were that the soundscapes from these three vegetation conditions would be different and that this difference would be: (i) detectable in the acoustic indices; and (ii) related to existing methods of assessing vegetation condition (i.e. BioCondition score). Using ANOVA, three soundscape indices (Acoustic Evenness Index (AEI), Acoustic Entropy Index (H) and Acoustic Diversity Index (ADI)) were significantly different between treatments of broad vegetation condition type (AEI p-value ≈ 0.016, H p-value ≈ 0.006, ADI p-value ≈ 0.038). Spearman’s correlation coefficients suggested that two indices had the greatest potential to link to BioCondition Score (AEI (−0.821) and H (0.893). We conclude that differences in ecosystem condition can be detected as differences in the soundscape and that there is a relationship between soundscapes and BioCondition score that indicates inherent biodiversity values. Our findings support soundscapes as a potential surrogate measure of vegetation condition for assessing biodiversity values. Although further research is required to strengthen these associations, this study is an early step towards understanding the link between soundscapes and vegetation condition as an indicator of biodiversity and overall ecosystem health.