The subject of this book is the plant cover of the Earth. In addition to a concise description of vegetation types, the focus is primarily on the causal relationships between the growth locations of characteristic plant species and plant communities on one hand, and the historically developmental, temporal, spatial, ecophysiological, and anthropogenic conditions on the other. Although the emphasis is on the "nature-oriented" plant cover that is little or not influenced by humans, the "culture-oriented" vegetation, which today occupies a larger area in climatically or edaphically favored regions, is also taken into account. Following an introductory chapter that lays the groundwork for the vegetation ecological classification of the Earth's surface, the living conditions of zonal, extrazonal, and azonally distributed vegetation are discussed.