Forest mensuration is one of the most fundamental disciplines within forest and related sciences. It deals with the measurement of trees and stands and the analysis of the resultant information. During the early days of sustained forest management simple measurement and estimation methods and with the analysis of inventory and research data were available. The middle of last c- tury, however, witnessed a worldwide increase in the need for more quan- tative information about trees and stands. This generated the need for more sophisticated methods to obtain and analyze forest data. This development was followed by a phenomenal explosion of information. During the past decades there has been fruitful cooperation between the Institute of Forest Inventory and Forest Growth, formerly “Institute of Forest Management and Forest Yield Sciences� of the University of Gottingen, ¨ Germany and the Faculty of Forestry of the University of Stellenbosch, South Africa. This book is one of the results of this fruitful cooperation between these institutions.