Tree Rings and Natural Hazards : A State-Of-The-Art

Dendrogeomorphology Beginnings and Futures: A Personal Reminiscence My early forays into dendrogeomorphology occurred long before I even knew what that word meant. I was working as a young geoscientist in the 1960s and early 1970s on a problem with slope movements and deformed vegetation. At the same time, unknown to me, Jouko Alestalo in Finland was doing something similar. Both of us had seen that trees which produced annual growth rings were reacting to g- morphic processes resulting in changes in their internal and external growth p- terns. Dendroclimatology was an already well established field, but the reactions of trees to other environmental processes were far less well understood in the 1960s. It was Alestalo (1971) who first used the term, dendrogeomorphology. In the early 1970s, I could see that active slope-movement processes were affecting the growth of trees in diverse ways at certain localities. I wanted to learn more about those processes and try to extract a long-term chronology of movement from the highly diverse ring patterns.

The initial employment of tree rings in natural hazard studies was simply as a dating tool and rarely exploited other environmental information and records of damage contained within the tree. However, these unique, annually resolved, tree-ring records preserve valuable archives of past earth-surface processes on timescales of decades to centuries. As many of these processes are significant natural hazards, understanding their distribution, timing and controls provides valuable information that can assist in the prediction, mitigation and defence against these hazards and their effects on society.

Tree Rings and Natural Hazards provides many illustrations of these themes, demonstrating the application of tree rings to studies of snow avalanches, rockfalls, landslides, floods, earthquakes, wildfires and several other processes. Several of the chapters are "classic studies", others represent recent applications using previously unpublished material. They illustrate the breadth and diverse applications of contemporary dendrogeomorphology and underline the growing potential to expand such studies, possibly leading to the establishment of a range of techniques and approaches that may become standard practice in the analysis of natural hazards in the future.