A Comparison of Analytical Approaches for Detecting Diameter Growth Trends: Case Studies from Switzerland

Abstract

Growth patterns in forests can be monitored using three approaches: assessments on permanent growth and yield plots, tree ring and stem analyses and forest inventories. Each of the three approaches has distinct advantages and disadvantages. To evaluate the effects of the three approaches on the detection and description of growth trends, they are applied to three identical areas: Switzerland, the Toppwald region in the Canton of Berne and the selection forests in the Toppwald region. The results of the case studies are discussed and the specific contribution of each approach for monitoring forest growth is highlighted. The data presented show a clear increase in growth rates in the last decades. However, these growth rates cannot be related to site productivity alone; confounding factors are very likely.