It is the policy of the federal Canadian Forestry Service to sponsor research initiatives from the private sector that are judged to be pertinent to its mandate and offer particular promise towards the optimal management of Canadian forest resources. This book is based on such an initiative. It represents the philosophy of the author himself and is in no way constrained by the views of the sponsoring agency. Over the past two decades Dr J. A. C. Fortescue has become well known at a number of research centers throughout the world. He has pioneered the approach to environmental understanding that is comprehensively developed in this text. The limitations of traditional compartmentalized approaches are depre- cated and the case is made for a holistic rethinking of basic concepts and princi- ples. Landscape Geochemistry is the disciplinary outcome that gives expression to this rethinking. It may be viewed as the minimum scale of conceptual approach necessary in the environmental sciences to solve present-day problems and to exploit future opportunities.