The potential use of acoustic indices for biodiversity monitoring at long-term ecological research (LTER) sites: a summary of current knowledge, equipment and methods

Passive acoustic monitoring (PAM) has been identified as a high priority research area by eLTER (Long-Term Ecosystem Research in Europe). This document provides background information and explores the potential for using acoustic indices as part of the suite of monitoring at UK Environmental Change Network (ECN) long-term ecological research (LTER) sites. We explore some of the concepts around acoustic indices, their usefulness, and provide practical information on how to choose and use indices as part of PAM. A method is proposed for using acoustic indices as part of ECN/LTER site monitoring. Its aim is to open the discussion on how we proceed in developing a standardised method for use of acoustic indices in long-term monitoring. The method proposed is not intended as a fait-accompli.