Book excerpt: Environmental indicators, such as global temperatures and pollutant concentrations, attract scientists' attention and often make the headlines. Equally important to policymaking are indicators of the ecological processes and conditions that yield food, fiber, building materials and ecological "services" such as water purification and recreation. This book identifies ecological indicators that can support U.S. policymaking and also be adapted to decisions at the regional and local levels. The committee describes indicators of land cover and productivity, species diversity, and other key ecological processesâ€"explaining why each indicator is useful, what models support the indicator, what the measured values will mean, how the relevant data are gathered, how data collection might be improved, and what effects emerging technologies are likely to have on the measurements. The committee reviews how it arrived at its recommendations and explores how the indicators can contribute to policymaking. Also included are interesting details on paleoecology, satellite imagery, species diversity, and other aspects of ecological assessment. Federal, state, and local decision-makers, as well as environmental scientists and practitioners, will be especially interested in this new book.