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Université de Fribourg

Changes in wood anatomy in tree rings of Pinus pinaster Ait. following wounding by flash floods

Ballesteros, J.A. ; Stoffel, Markus ; Bodoque, J.M. ; Bollschweiler, Michelle ; Hitz, Oliver ; Díez-Herrero, A.

In: Tree-Ring Research, 2010, vol. 66, no. 2, p. 93-103

This paper analyzes the anatomical response of Pinus pinaster Ait. following wounding by flash floods. A total of 14 wood samples were taken from 14 different scarred trees located on the river banks of the Arroyo Cabrera torrent (Spanish Central System). In addition, 20 increment cores were collected from undisturbed and healthy P. pinaster trees to build a local reference chronology. For the...

Université de Fribourg

The European mountain cryosphere: a review of its current state, trends, and future challenges

Beniston, Martin ; Farinotti, Daniel ; Stoffel, Markus ; Andreassen, Liss M. ; Coppola, Erika ; Eckert, Nicolas ; Fantini, Adriano ; Giacona, Florie ; Hauck, Christian ; Huss, Matthias ; Huwald, Hendrik ; Lehning, Michael ; López-Moreno, Juan-Ignacio ; Magnusson, Jan ; Marty, Christoph ; Morán-Tejéda, Enrique ; Morin, Samuel ; Naaim, Mohamed ; Provenzale, Antonello ; Rabatel, Antoine ; Six, Delphine ; Stötter, Johann ; Strasser, Ulrich ; Terzago, Silvia ; Vincent, Christian

In: The Cryosphere, 2018, vol. 12, no. 2, p. 759–794

The mountain cryosphere of mainland Europe is recognized to have important impacts on a range of environmental processes. In this paper, we provide an overview on the current knowledge on snow, glacier, and permafrost processes, as well as their past, current, and future evolution. We additionally provide an assessment of current cryosphere research in Europe and point to the different...

Université de Fribourg

Debris flows on forested cones – reconstruction and comparison of frequencies in two catchments in Val Ferret, Switzerland

Bollschweiler, Michelle ; Stoffel, Markus

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...

Université de Fribourg

Dynamics in debris-flow activity on a forested cone — A case study using different dendroecological approaches

Bollschweiler, Michelle ; Stoffel, Markus ; Schneuwly, Dominique M.

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...

Université de Fribourg

Reconstructing spatio-temporal patterns of debris-flow activity using dendrogeomorphological methods

Bollschweiler, Michelle ; Stoffel, Markus ; Ehmisch, Melanie ; Monbaron, Michel

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...

Université de Fribourg

Traumatic resin ducts in Larix decidua stems impacted by debris flows

Bollschweiler, Michelle ; Stoffel, Markus ; Schneuwly, Dominique M.

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...

Université de Fribourg

Tree-ring reconstruction of past lahar activity at Popocatépetl volcano, Mexico

Bollschweiler, Michelle ; Stoffel, Markus ; Vázquez Selem, Lorenzo ; Palacios, David

In: The Holocene, 2010, vol. 20, no. 2, p. 265-274

Lahars represent a major threat on the slopes of volcanoes all over the world. In order to realistically assess hazards, knowledge on the occurrence and timing of past lahar activity is of crucial importance. However, archival data on past events is usually scarce or completely missing. Tree-ring records have repeatedly proved to be a reliable data source for the reconstruction of past...

Université de Fribourg

Fine-scale spatial patterns of the Tertiary relict Zelkova abelicea (Ulmaceae) indicate possible processes contributing to its persistence to climate changes

Bosque, Marta ; Adamogianni, Maria Irene ; Bariotakis, Michael ; Fazan, Laurence ; Stoffel, Markus ; Garfi, Giuseppe ; Gratzfeld, Joachim ; Kozlowski, Gregor ; Pirintsos, Stergios

In: Regional Environmental Change, 2014, vol. 14, no. 2, p. 835–849

In this paper, the fine-scale spatial patterns of the Tertiary relict Zelkova abelicea (Lam.) Boiss. were studied (1) to reveal processes that contributed to its persistence to climate changes and (2) to assist future conservation planning, with the purpose of shifting the attention of conservation practitioners from patterns to processes. Results of the fine-scale spatial patterns of Z. abelicea...

Université de Fribourg

Der Fidazer Felssturz von 1939: Analyse & Simulation

Cabernard, Vendelin ; Stoffel, Markus ; Monbaron, Michel

In: Mitteilungen der Versuchsanstalt für Wasserbau, Hydrologie und Glaziologie an der Eidgenössischen Technischen Hochschule Zürich, 2004, vol. 184, p. 1-12

Am 10. April 1939 ging auf dem Gebiet des Dorfes Fidaz (Flims) ein mächtiger Felssturz nieder, 18 Personen fanden den Tod. Die vorliegende Studie hat zum Ziel, diesen Felssturz mit zeitgenössischen Dokumenten neu aufzurollen. Dazu wurden Augenzeugenberichte, Bilder und Karten zur Rekonstruktion des Felssturzes herangezogen und Berechnungen zur mittleren Geschwindigkeit der Sturzmasse...