V Sloveniji se povečuje osutost bukove krošnje
Beech defoliation in Slovenia is increasing

english
slovenian

2021

volume 79, issue 5/6

beech   climatic change   damage   drought   ice storm   tree crown defoliation

Zveza gozdarskih društev Slovenije
(Obvezni izvod spletne publikacije)

Recently, we noticed decline of the common beech (Fagus sylvatica L.). The aim of this article is to present the long- -term trend of the common beech defoliation in Slovenia and to explain the defoliation share using the data from the inventory of damage agents in the framework of the annual inventory of the forest devaluation and damage. Thereby we applied the database on the monitoring of the tree defoliation and damage on the M6 permanent sampling plots (Level I) on the systematical 16 % 16 km grid in the period 1993%2020. The results show the average defoliation of the beech increased from 13.9 % to 32.2 % from 1993 to 2020. The long-term linear trend has shown that the average beech defoliation increased for 0.63 % yearly. The extremely dry year 2003, when the defoliation trend increased from 0.61 % to 0.94 % yearly, represented the milestone for the average beech defoliation trend. The trend of beech defoliation increase was detected in all studied locations. We found that the average beech defoliation is increasing more rapidly in the south and west of the country. The disastrous ice storm in 2014 caused a drastic change in the beech defoliation causes. In the period before the ice storm in 2014, the defoliation of the beech was best explained by the damage due to the insects. After the 2014 ice storm, increased the damages of the beech due to sleet, fungi, direct manmade impacts (ample ice storm sanitations) and other factors. The ice storm caused permanent consequences on the beech forests and the damage due to the ice storm and consequent sanitation are still visible today, which is also visible from the inventory of the beech damage agents. In the last two years, 2019%2020, fungi are the most important cause of beech damage. After 2014, the beech damage due to the insects decreased. The exact causes for the general decrease of beech health throughout Slovenia are not known yet.

04.12.2024