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Due to the likelihood of global climate change, the frequency and magnitude of natural hazards such as mass movements may likewise change, thus favouring the refinement of methods to detect and quantify geomorphic events when precise records are not available. Geomorphic events typically have a significant effect on tree growth, e.g., reaction wood marked by changes in ring widths and wood density. To date, several dendroecological techniques have been developed to document the occurrence of these events but it rarely has been possible to retrieve additional information from reaction wood concerning the precise kind and intensity of geomorphic events. Additional qualitative information inferred from reaction wood of trees holds the potential to not only document but also estimate important characteristics of natural hazard events. To refine the methods already used in dendrogeomorpology, experiments simulating various geomorphic events were used to monitor subsequent wood anatomical responses of Fagus sylvatica and Alnus glutinosa. The preliminary results indicate that these two common broadleaf tree species show variations in their reactions to different experimental treatments.

New increment core samples of Toona ciliata collected in the Australian tropics and subtropics compared to already existing material from the Upper Kangaroo Valley, near Sydney exhibit distinct differences in tree-ring structures. This necessitated a closer examination of the wood anatomy, possible false rings and the speciesʼ crossdating capacity in northeast Australia. During tree-ring analysis two growth anomalies (extensive zones of narrow and indistinct rings) and three types of false rings were discovered which complicated crossdating. However, in growth experiments only one type of false ring could be induced artificially by totally defoliating young trees. It was possible to alter their phenological performance by artificially changing the environmental conditions. Visual crossdating of samples originating from northeast Australia was feasible within and between trees. For selected years a positive relationship between ring width and precipitation data was found.