The potential of broad-leaved trees for dendrogeomorphic research: wood anatomical analysis of injuries

The objective of this thesis is to determine and exploit the potential of broad-leaved trees for dendrogeomorphic research. Wounded trees from several broad-leaved species were sampled along torrents in the Swiss Alps as well as in snow avalanche paths in Norway and Iceland. Injuries were studied at the macroscopic level to date events and at the microscopic level to analyze wound-induced changes in wood anatomy so as to improve the detection of injuries in tree-ring series. Xylem cells were examined radially (before and after the injury) and tangentially (around the tree circumference) in order to identify variations in wood anatomical features. The formation of more and narrower earlywood vessels as well as the initiation of more and larger rays were obvious in a very short time after the disturbance, emphasizing that altered wood anatomical features can serve as proxy records of past events with seasonal to annual resolution