This updated and modernized edition of Essentials of Ecology provides the scientific foundation necessary for students to understand fundamental ecological issues. The authors integrate new material alongside classic examples to outline clearly the basics of ecology from theoretical underlying principles to practical applications. The book is divided into four sections. The first covers basic statistical and methodological approaches, and the evolutionary processes that result in contemporary ecological patterns. Section two discusses how species’ tolerance of environmental conditions and requirement for resources determine their ecological niche and geographical distribution across scales. Section three forms the main body of the text and introduces key ecological concepts to understand population processes, the organization of communities, the determinants of patterns in species richness, and the flux of energy and matter through ecosystems. The final section applies these concepts to current ecological issues including sustainability of food production in the face of increasing human population growth, pollution and its impact on ecosystem services, conservation of biodiversity and the threat of global climate change. Unanswered ecological questions are highlighted throughout the text, history boxes outline landmarks in the development of ecology as a scientific discipline, ‘topical ‘ECOncerns’ boxes highlight ethical, social and political questions in ecology, quantitative boxes explain mathematical aspects, and review questions are included at the end of each chapter to stimulate discussion and debate. This broad and comprehensive coverage precludes in-depth analysis of any single topic, but it nevertheless provides a sound basis for new students in ecology.