Book excerpt: Before any other influences began to fashion life and its lavish diversity, geological events created the initial environments--both physical and chemical--for the evolutionary drama that followed. Drawing on case histories from around the world, Arthur Kruckeberg demonstrates the role of landforms and rock types in producing the unique geographical distributions of plants and in stimulating evolutionary diversification. His examples range throughout the rich and heterogeneous tapestry of the earth's surface: the dramatic variations of mountainous topography, the undulating ground and crevices of level limestone karst, and the subtle realm of sand dunes. He describes the ongoing evolutionary consequences of the geology-plant interface and the often underestimated role of geology in shaping climate. Kruckeberg explores the fundamental connection between plants and geology, including the historical roots of geobotany, the reciprocal relations between geology and other environmental influences, geomorphology and its connection with plant life, lithology as a potent selective agent for plants, and the physical and biological influences of soils. Special emphasis is given to the responses of plants to exceptional rock types and their soils--serpentines, limestones, and other azonal (exceptional) substrates. Edaphic ecology, especially of serpentines, has been his specialty for years. Kruckeberg's research fills a significant gap in the field of environmental science by connecting the conventionally separated disciplines of the physical and biological sciences. Geology and Plant Life is the result of more than forty years of research into the question of why certain plants grow on certain soils and certain terrain structures, and what happens when this relationship is disrupted by human agents. It will be useful to a wide spectrum of professionals in the natural sciences: plant ecologists, paleobiologists, climatologists, soil scientists, geologists, geographers, and conservation scientists, as well as serious amateurs in natural history.