This volume sits at the cross-roads of a number of areas of scientific interest that, in the past, have largely kept themselves separate - agriculture, forestry, population genetics, ecology, conservation biology, genomics and the protection of plant genetic resources. Yet these areas also have a lot of common interests and increasingly these independent lines of inquiry are tending to coalesce into a more comprehensive view of the complexity of plant-pathogen associations and their ecological and evolutionary dynamics. This interdisciplinary source provides a comprehensive overview of this changing situation by identifying the role of pathogens in shaping plant populations, species and communities, tackling the issue of the increasing importance of invasive and newly emerging diseases and giving broader recognition to the fundamental importance of the influence of space and time (as manifest in the metapopulation concept) in driving epidemiological and co-evolutionary trajectories.