The main reasons for writing this book on the management of forest soils in Croatia are the following: 1. The need for wood today is increasing, in spite of the successful quest for its substitution in building, househoid and other activities. At the same time attitudes towards the forest are changing because of its many benefits, which as a rule are more valuable than the market value of timber production. The development of urbanisation has increased the importance of the forest for human health, and the hydrological and anti-erosive role of the forest has become more important and evident. In Croatia forests are becoming increasingly important for the development of modern tourism, recreation and other activities (pharmacy, wildlife management, protection of agriculture and defence of the homeland). The numerous natural and management functions of the forest require a new approach to their assessment and exploitation. It is very important to determine the conditions which best ensure the success of the most utilised forest cultures (natural stands and cultures). Such optimal economic and ecological role of Croatian forests can only be achieved by sufficient knowledge and appreciation of their pedological conditions, because the soil as an energetic block (reactor) of the forest ecosystems is equally important for the physical, productive and social role of the forest. 2. Whenever possible, during 40 years of pedological research, I concentrated on the importance of forest soils in management. At the time I had the fortune to investigate a large number of localities with preserved, and normal managed forest ecosystems. Thus, I was able to collect data on the pedogenic (natural) characteristics of forest soils in Croatia. I believe that the information gathered in this respect is my most valuable contribution to Croatian pedological heritage, which will be of considerable importance for future investigators of the state (properties and processes) of our forest soils and also of similar forest soils. It was therefore necessary to collect this information, and all other acquired knowledge and experience, in a suitable form for future investigators, available to a wider circle of experts who are today interested in the comprehensive role of the forest and forest soil. 3. No book has been published in Croatia dealing with forest soils and their management since Sandor's "Tloznanstvo (Soil Science)" I and II (1914,1915), although pedological research of our forest soils has continued for more than a century, data on which can be found in various scattered papers. Thus, the intention was for this book to alleviate this omission in our forest and pedological literature. The book has been written from the standpoint of forestry pedology, the foundation of which was accurately, and with foresight, determined by our first educated pedologist, Prof. Ferdo Sandor (1914,1915). He was ciear with regard to the basic task in the management of forest soils. "The duty of the forest owner and the most important task of the forester - while intensively exploiting the strength of the soil - is to ensure that the soil does not become impoverished, so that it permanently provides a determined income, and accordingly they are obliged to leave their successors forest soil with which they were entrusted in a satistactory condition and whenever possible to attempt to improve less valuable or poorer soils, so that the national wealth is not decreased" (Sandor 1915). Sandor's messages had a powerful influence on the course of research of our forest soils, and consequently also on the project of this book. Our aim was to analyse as far as possible the following problems: (1) Contemporary knowledge and the nature and function of forest soil. (2) The physiographic characteristics of types of our soils and their bioclimatic derivations. (3) Relationships between soil and vegetation cover. (4) Geochemistry of forest plants and trophicity of soil. (5) The productivity of soils. (6) Management assessment of soils and grading of their suitability for different purposes. (7) Management interventions and state of soil. (8) Technogenesis of soils (the problems of damage and protection). The content of the book does not cover all questions in the field of forest pedology for two reasons. Some questions have not been sufficiently studied (e.g. biology and mineralogy of the soil) while others, e.g. general knowledge of genesis, evolution and general physiography of soil have been sufficiently analysed in more recent literature, such as uiniversity textbooks and encyclopaedia).
