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

Abstract

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.