The world's ecosystems are increasingly threatened by human development. Ecological impact assessment (EcIA) is used to predict and evaluate the impacts of development on ecosystems and their components, providing the information needed to ensure that ecological issues are given full and proper consideration in development planning. Environmental impact assessment (EIA) has emerged as a key to sustainable development by integrating social, economic and environmental issues in many countries. EcIA has a major part to play as a component of EIA but also has other potential applications in environmental planning and management.Ecological Impact Assessment provides a comprehensive review of the EcIA process and summarizes the ecological theories and tools which can be used to understand, explain and evaluate the ecological consequences of development proposals. It is intended for the many individuals and companies involved in EIA and EcIA, as well as other areas of environmental management where impacts on ecosystems need to be evaluated. It will benefit planners, regulators, environmental consultants and scientists and will also provide an invaluable source-book and guide for the growing number of undergraduate students taking courses in applied ecology, EIA and related topics in environmental science.