Application of active acoustic transducers in monitoring and assessment of terrestrial ecosystem health—A review

Abstract

1. Urbanization, agricultural production, natural resource extractions and climate change are global drivers of terrestrial ecosystem degradation and decline in ecosystem health. Assessing vegetation structures provides valuable direct and indirect information on biodiversity and ecosystem health, since plant communities govern terrestrial ecosystem functions and overall biodiversity. 2. A growing body of literature supports the hypothesis that acoustic profiling and characterization of soundscapes may reveal natural patterns and ecosystem responses to environmental disturbances. Although assessments of ecosystem soundscapes are a promising tool for ecological monitoring, the influence of vegetation structure on acoustic indices remains largely unaddressed. An effective non-invasive approach to monitoring ecosystem health includes use of active acoustic transducers, which convert mechanical/acoustic energy into electrical energy and visa-versa.3. This article reviews and discusses possible applications (and also constraints) of active acoustic transducers in monitoring and assessments of terrestrial ecosystem health. Specifically, this article includes a brief introduction to the basic principles of sound and types of active acoustic transducers. Moreover, we provide reviews of common uses of active acoustic transducers in assessing plant structures and plant functional traits.4. We emphasize that active acoustic transducers can be used to analyse plant characteristics in a remote, scalable, non-invasive and cost-effective manner to characterize overall terrestrial ecosystem health. Suggestions and recommendations for future research and management directions that may facilitate applications of acoustic transducers to natural terrestrial landscapes are provided.