Preface "Tree-ring reconstructions in natural hazards research"

Abstract

The different contributions illustrate how tree-ring analysis can be used to reconstruct natural hazards and provide information that may be used to understand the future occurrence of events. The papers also illustrate the breadth and diverse applications of contemporary dendrogeomorphology and underline the growing potential to expand these studies, possibly leading to the establishment of a range of techniques and approaches that may become standard practice in the analysis of specific hazards. In addition, data on process dynamics and triggers are of great value for the overall understanding of mass movements and the way they are influenced by changing climatic conditions. Such data represent compulsory prerequisites for realistic estimates of the current and for potential future evolution of earth-surface processes in space and time and a basis for future research in an even larger variety of geographic environments. In the introductory paper, Stoffel and Bollschweiler (2008) provide a broad overview on current approaches used in tree-ring reconstructions of natural disasters resulting from earth-surface processes and outline the impact that mass movements have on tree morphology, tree growth and wood anatomy. The second paper by Schneuwly and Stoffel (2008) reconstructs rockfall activity on a slope in the Swiss Alps using 154 wounds from 32 European larch (Larix decidua Mill.), Norway spruce (Picea abies (L.) Karst.) and Swiss stone pine (Pinus cembran L.) trees. The intra-annual position of wounds points to strong intra- and inter-annual variations of rockfall activity, with a clear peak (76%) in winter. Findings suggest that rockfall activity at the study site is driven by annual thawing processes and the circulation of melt water in preexisting fissures. Data also indicate that 43% of all rockfall events occurred in 1995, when two major precipitation events are recorded in nearby meteorological stations.