Exploring potential relationships between acoustic indices and ecosystem functions: a test on insect herbivory

Area of Science:

• Ecology
• Bioacoustics
• Ecosystem Function Monitoring

Background:

• Biodiversity loss is a significant global challenge.
• Passive acoustic monitoring (PAM) offers a non-invasive method for remote biodiversity assessment using soundscape recordings.
• The potential of PAM for monitoring ecosystem functions remains largely unexplored.

Purpose of the Study:

• To investigate the relationship between acoustic indices derived from PAM and insect leaf herbivory.
• To determine if PAM data can serve as a proxy for ecosystem functions related to insect activity.

Main Methods:

• Recorded evening soundscapes in 13 plots across four subtropical forests in South China.
• Quantified insect leaf herbivory on seedlings, including total damage and damage by specific feeding guilds (chewers, miners, etc.).
• Analyzed acoustic data using seven common acoustic indices to assess soundscape complexity.

Main Results:

• Acoustic entropy index showed a positive correlation with total insect leaf herbivory.
• Higher acoustic complexity, indicated by higher entropy index values, was linked to greater herbivory.
• The relationship was stronger for chewing insects, suggesting acoustic indices capture soniferous insect groups more effectively.

Conclusions:

• PAM holds potential for monitoring ecosystem functions, specifically insect herbivory.
• Acoustic indices can reflect certain aspects of insect activity and their impact on ecosystems.
• Further research is needed to optimize PAM for ecosystem function assessment.