Patterns in the numbers of species have fascinated naturalists for centuries. Understanding the causes of latitudinal gradients in species richness and biodiversity 'hotspots' is often considered to be the holy grail of ecology. Extinctions in the past offer insight into what may occur in the future under climate change and habitat loss. The subject of vegetation-climate interaction is a compelling issue scientifically and is also of importance for land management practices. This book examines the state of current understanding of species richness patterns and their explanations. As well as the present day world it deals with diversification and extinction, in the conservation of species richness, and the difficulties of assessing how many species remain to be discovered. The author will provide a readable, informative and up-to-date account of the patterns and controls on biodiversity and the scientifically compelling subject of vegetation-climate interaction. Jonathan Adams is uniquely qualified to write on the far-reaching and many-faceted subject of species richness. He is Assistant Professor in Ecology, Rutgers University, New Jersey, and is currently working on testing aspects of the Janzen-Connell hypothesis for forest diversity. He has published about 50 papers on many different aspects of ecology, including species richness, and the recently published Vegetation-Climate Interactions for Praxis.