In: Global and Planetary Change, 2008, vol. 60, no. 3-4, p. 222-234
Debris-flow activity on the forested cone of the Ritigraben torrent (Valais, Swiss Alps) was assessed from growth disturbances in century-old trees, providing an unusually complete record of past events and deposition of material. The study of 2246 tree-ring sequences sampled from 1102 Larix decidua Mill., Picea abies (L.) Karst. and Pinus cembra ssp. sibirica trees allowed reconstruction of 123...
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In: Tree Physiology, 2008, vol. 28, no. 3, p. 355-366
The bending and growth characteristics of large fresh stems from four silver fir (Abies alba Mill.) and three Norway spruce (Picea abies (L.) Karst.) trees were studied. Twenty logs taken from different stem heights were subjected to four-point bending tests. From the bending test records, we calculated stress–strain curves, which accounted for detailed log taper, shear deformation and self...
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In: Tree Physiology, 2008, vol. 28, no. 2, p. 255-263
Following mechanical injury, stems of many conifers produce tangential rows of traumatic resin ducts (TRDs), the distribution of which has been used to date geomorphic events. However, little is known about how far TRD formation extends tangentially and axially from the point of injury or what the time course of TRD appearance is. We analyzed 28 injuries in eight Larix decidua Mill. tree...
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In: Schweizerische Zeitschrift fur Forstwesen, 2007, vol. 158, no. 6, p. 128-141
To effectively prevent rockfall related disasters below forested slopes, silvicultural, eco-engineering, civil engineering or mixed techniques can be used. To do this in a cost-efficient manner it is necessary to know the following: 1) where rockfall events occur and which magnitudes are likely, 2) to what extent the forest reduces the run-out distances, the jump heights and the energies of rocks...
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In: Geomorphology, 2007, vol. 87, no. 4, p. 337-351
Debris flows are a major threat in many parts of the Alps, where they repeatedly cause severe damage to infrastructure and transportation corridors or even loss of life. Nonetheless, the spatial behavior of past debris-flow activity and the analysis of areas affected during particular events have been widely neglected in reconstructions so far. It was therefore the purpose of this study to...
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In: Tree Physiology, 2007, vol. 27, p. 1229-1241
To provide data and methods for analyzing stem mechanics, we investigated bending, density and growth characteristics of 207 specimens of fresh wood from different heights and radial positions of the stem of one mature Norway spruce (Picea abies L. Karst.) tree. From the shape of each stress–strain curve, which was calculated from bending tests that accounted for shear deformation,...
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In: Catena, 2008, vol. 72, no. 1, p. 67-78
Dendrogeomorphological analyses of trees affected by debris flows have regularly been used to date past events. However, this method has always been limited to forested cones where trees registered the impact of previous events. The minimum age dating of trees growing in the debris deposits can, in contrast, provide information on the latest possible moment of past activity. In this paper, we...
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In: Natural Hazards and Earth System Sciences, 2007, vol. 7, no. 2, p. 207-218
Debris flows represent a major threat to infrastructure in many regions of the Alps. Since systematic acquisition of data on debris-flow events in Switzerland only started after the events of 1987, there is a lack of historical knowledge on earlier debris-flow events for most torrents. It is therefore the aim of this study to reconstruct the debris- flow activity for the Reuse de Saleinaz and...
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In: Natural Hazards, 2006, vol. 39, no. 1, p. 51-70
Over the last few years, rockfall research has increasingly focused on hazard assessment and risk analysis. Input data on past rockfall activity were gathered from historical archives and lichenometric studies or were obtained through frequency– volume statistics. However, historical records are generally scarce, and lichenometry may only yield data with relatively low resolutions. On...
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In: Geophysical Research Letters, 2006, vol. 33, p. L16404
Tree-ring based reconstructions of 123 debris-flow events in a case-study area of the Swiss Alps since AD 1570 show enhanced activity during the wet periods (1864–1895) following the last LIA glacier advance and in the early decades of the 20th century. In contrast, comparably low activity can be observed since 1995, with only one event recorded. From the reconstructions and based on RCM...
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