Book excerpt: Ecological indicators and surrogates are used widely by resource managers to monitor and understand complex biota and ecosystem processes. Their potential to guide complex resource management has meant they have been proposed for use in all ecosystems worldwide. Despite extensive research into indicators and surrogates, there remains much controversy about their use, in addition to major issues and knowledge gaps associated with their identification, testing and application. Indicators and Surrogates of Biodiversity and Environmental Change provides insights into the use of indicators and surrogates in natural resource management and conservation – where to use them, where not to use them, and how to use them. Using an ecological approach, the chapters explore the development, application and efficacy of indicators and surrogates in terrestrial, aquatic, marine and atmospheric environments. The authors identify current gaps in knowledge and articulate the future directions for research needed to close those gaps. This book is written by the world’s leading thinkers in the area of indicators and surrogates. It is the first major synthesis of learnings about indicators and surrogates and will be a critical resource for the vast number of people developing and applying them in ecosystems around the world. It will be an essential resource for scientists, policy makers and students with interests in surrogates and indicators.