Zielonka, T., Holeksa, J. and Malcher, P. 2009. Disturbance Events in a Mixed Spruce – Larch Forest in the Tatra Mts., Western Carpathians – a Tentative Reconstruction. Baltic Forestry, 15 (2): 161-167
In this study paper we studied the effect of a severe and large scale windstorm which destroyed 12,000 ha of the Lariceto – Piceetum forest in the Slovakian High Tatra Mts. in 2004. Despite similar diameter and age structure of spruce and larch populations both species exhibited different resistance on the storm impact. Larch trees proved to be more resistant on heavy wind than spruce, and chances of survival of larch increased with its diameter. Spruce was almost totally eliminated from the stand. Irrespective of the species more trees died because of uprooting then because of breakage. The number of broken spruce stems increased with diameter compared with uprootings. Among thinnest diameter classes the number of breakages was more than twice lower than uprootings and among the thickest trees (exceeding diameter of 60 cm) most trees were broken. In case of larches most vulnerable on wind were thinner trees. Larch trees in diameter exceeding 40 cm had 50% survival chances while among stems below 40 cm only 17% remained intact after windstorm. The higher survival rate of larch probably resulted from their small crowns that were leafless in late fall when windstorm occurred. This shows a direct selective effect of a wind as a disturbance factor in the Lariceto – Piceetum forest in Tatra Mts. Tentative analyses of tree-rings based on 75 cross – sections from the oldest stumps of the damaged trees indicated abrupt changes in the growth pattern during the last two hundred years. The synchronized and strong release pulses in spruces and larches in the 19th century may indicate the occurrence of severe and infrequent disturbances in the past.
Key words: dendroecology, disturbance, Larix decidua, Picea abies, release signal, Tatra Mts