Due to the long-term planning horizons and the great variety of natural, economic, and operational hazards affecting forest ecosystems, uncertainty and multiple risk are typical aspects of forest management. Applications of risk analysis are surprisingly rare, in spite of the rich assortment of sophisticated forest planning tools that are available today. The objective of this particular volume within the book series Managing Forest Ecosystems is to present state-of-the-art research results, concepts, and techniques regarding the assessment and evaluation of natural hazards and the analysis of risk and uncertainty relating to forest management. Various aspects of risk analysis are covered, including examples of specific modelling tools. The book is divided into three sections covering ecological perspectives, applications in engineering and planning, and methods applicable to economics and policy.

Due to the long-term planning horizons and the great variety of natural, economic, and operational hazards affecting forest ecosystems, uncertainty and multiple risk are typical aspects of forest management. Applications of risk analysis are surprisingly rare, in spite of the rich assortment of sophisticated forest planning tools that are available today. The objective of this particular volume within the book series Managing Forest Ecosystems is to present state-of-the-art research results, concepts, and techniques regarding the assessment and evaluation of natural hazards and the analysis of risk and uncertainty relating to forest management. Various aspects of risk analysis are covered, including examples of specific modelling tools. The book is divided into three sections covering ecological perspectives, applications in engineering and planning, and methods applicable to economics and policy.

In an lUlffianaged woodland, forest development follows a succession of periods of undisturbed natural growth, interrupted by intermediate loss or damage of trees caused by fire or wind or other natural hazards. In a managed woodland, the most important periodic disturbances are the thinning operations, which are often carried out at regular intervals and which usually have a significant effect on the future evolution of the resource. Thus, a realistic model of forest development includes both natural growth and thinnings. The key to successful timber management is a proper understanding of growth processes, and one of the objectives of modelling forest development is to provide the tools that enable foresters to compare alternative silvicultural treatments. Foresters need to be able to anticipate the consequences of a particular thinning operation. In most cases, total timber volume is not a very appropriate measure for quantifying growth or yields, or changes caused by thinning operations. Yield in economic terms is defined by the dimensions and quality attributes of the harvestable logs, and estimating timber products is a central issue of production-oriented growth and yield research. Introduction 2 Growth modelling is also an essential prerequisite for evaluating the consequences of a particular management action on the future development of an important natural resource, such as a woodland ecosystem.