Rockfall and snow avalanche impacts leave different anatomical signatures in tree rings of juvenile Larix decidua

In winter 1999, several buildings and cottages have been destroyed by a large snow avalanche in and around the village of Evolene (Valais, Switzerland). The age of the cottages destroyed by the event was supposed to be considerable, but the individual buildings were not dated. It was therefore the goal of this study to assess the age of one of the cottages with dendrochronological methods. The investigation was based on a local reference chronology composed of 19 reference larch trees (Larix decidua Mill.) from the Evolene region. The reference chronology was built through optical and statistical analyses of the samples as well as crossdating methods. The chronology extends back to 1642, with a minimum sample depth of three trees from 1654 and five trees from 1725. Through the comparison of the reference chronology with a piece of wood from the destroyed cottage, it was possible to date the outermost ring of the construction wood to AD 1693. The age of the dated construction wood suggests that the flow path of the 1999 avalanche was unusual and that it affected a sector that has, most probably, not suffered from similar events since at least 300 years.

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Rockfall and snow avalanche impacts leave different anatomical signatures in tree rings of juvenile Larix decidua

Tree Physiology ◽

10.1093/treephys/28.11.1713 ◽

2008 ◽

Vol 28 (11) ◽

pp. 1713-1720 ◽

Cited By ~ 44

Author(s):

M. Stoffel ◽

O. M. Hitz

Keyword(s):

Tree Rings ◽

Larix Decidua ◽

Snow Avalanche

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INTRA-SITE VARIATION IN TREE RINGS OF LARCH (LARIX DECIDUA MILL.) FROM POLISH CARPATHIAN MOUNTAINS

17th International Multidisciplinary Scientific GeoConference SGEM2017, Water Resources. Forest, Marine and Ocean Ecosystems ◽

10.5593/sgem2017/32/s14.113 ◽

2017 ◽

Author(s):

Monika Chuchro

Keyword(s):

Tree Rings ◽

Larix Decidua ◽

Carpathian Mountains ◽

Site Variation

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Reconstructing snow-avalanche activity with tree rings in Maramureş Mountains (Eastern Carpathians, Romania)

10.5194/egusphere-egu2020-20060 ◽

2020 ◽

Author(s):

Armelle Decaulne ◽

Ionela-Georgiana Răchită ◽

Mihai Hotea ◽

Vasile Timur Chiş ◽

Olimpiu Traian Pop

Keyword(s):

Tree Ring ◽

Tree Rings ◽

Climatic Factors ◽

Climatic Conditions ◽

Snow Avalanche ◽

Snow Avalanches ◽

Joint Research ◽

Eastern Carpathians ◽

Joint Research Project ◽

Callus Tissues

Snow avalanches represent a common phenomenon in Maramure&#351; Mountains (Eastern Carpathians, Romania) where they occur frequently on higher steep slopes and reach in the runout zones the valley bottoms below 1000 m a.s.l. The presence of particular topo-climatic conditions influences the patterns of avalanche activity in terms of past frequency and spatial extent along the slope valleys. As the past snow-avalanche activity is not documented by written reports in the area, reliable information about avalanche history is missing. However, the slopes are forested, trees repeatedly disturbed by snow avalanches record evidence of past events. For this study we reconstructed the avalanche activity using tree rings as a source of proxy data. To date the snow-avalanche history, dendrochronological investigations have been carried out in two avalanche paths, along which living trees showed clear external signs of past disturbances related to mechanical impacts produced by snow avalanches. In each investigated path, a total number of 52 and respectively 118 trees have been sampled and their spatial position recorded with a GPS device. Tree-growth anomalies (e.g. scars, callus tissues, the onset sequences of tangential rows of traumatic resin ducts, compression wood, growth suppression and release sequences) related to snow avalanche disturbance identified within tree rings served to reconstruct past events with an annual resolution. The results indicate that, apart the 2005 major event witnessed and also confirmed by tree-ring dating, multiple other events have been reconstructed since the beginning of 20th century. Despite some inherent limitations of tree-ring methods in reconstructing past avalanche events, these dendrochronological investigations confirm their utility in deciphering the patterns of avalanche activity in Maramure&#351; Mountains. Tree-ring studies contribute to a better understanding of the role of topographical and climatic factors which influence the spatio-temporal occurrence of snow avalanches.This study represents a contribution to the joint research project 09-AUF, &#8216;&#8216;Activit&#233; des avalanches de neige dans les Carpates Orientales Roumaines et Ukrainiennes - ACTIVNEIGE&#8217;&#8217;, co-funded by the Agence Universitaire de la Francophonie (AUF) and Institutul de Fizic&#259; Atomic&#259; (IFA), Romania.

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Snow–avalanche history reconstructed with tree rings in Parâng Mountains (Southern Carpathians, Romania)

Revista de Geomorfologie ◽

10.21094/rg.2020.099 ◽

2020 ◽

Vol 22 (1) ◽

pp. 73-85

Author(s):

Corina TODEA ◽

Olimpiu Traian Pop ◽

Daniel GERMAIN

Keyword(s):

Tree Rings ◽

Past History ◽

Snow Avalanche ◽

Snow Avalanches ◽

Average Return ◽

Historical Archives ◽

Prone Area ◽

Forested Areas ◽

Pertinent Information ◽

Southern Carpathians

Snow avalanches are a common phenomenon in Parâng Mountains (Southern Carpathians, Romania) perturbing tourism activities and associated infrastructures, damaging forests, and causing fatalities. Its past history is an essential information to gather while assessing the hazard zonation areas. Usually, in Romania snow–avalanche activity occurring in forested areas are neither monitored, nor recorded by historical archives. In these areas, environmental archives such as tree rings may provide useful information about the past avalanche activity. The purpose of the present study is to reconstruct snow–avalanche history with tree rings along a path located below Cârja Peak (2405 m a.s.l.), an area where past snow–avalanche activity still remains underestimated. In this sense, 57 Norway spruce (Picea abies (L.) Karst.) trees showing clear signs of disturbance by snow avalanches were sampled and the growth anomalies associated with the mechanical impact produced by snow avalanches on trees were identified within their rings and served to reconstruct past events. The reconstructed chronology covers the period 1994–2018 showing the occurrence of a minimum of 11 major events, with an average return period of 2.1 years. Tree–ring records provided the most consistent avalanche event chronology in the study area. Although the limited extension of the chronology back in time, a better understanding of snow–avalanche history which may be gained through dendrochronological reconstructions represent nonetheless useful and pertinent information to consider before the implementation and development of infrastructure in this mountain avalanche–prone area.

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