The Conservation of Plant Biodiversity highlights the different levels of biological organisation at which conservation is being addressed - the gene, the species and the community. Conservation biology is faced with several controversial issues such as the dichotomy between the preservation of individual species versus a broader focus on the environment, the relative importance to give to endangered species, the design and management of reserves and the drive for increasing agricultural productivity through plant improvement versus the drive to maintain traditional peasant varieties in cultivation. These and other issues are dealt with here by emphasising and exploring the underlying scientific principles. The conservation of whole communities emerges as the paramount strategy for maintaining the evolutionary potential of plant life.