Author(s):
1. Krunoslav Teslak, Faculty of Forestry, Zagreb, Croatia
2. Marijana Žunić, Faculty of Forestry, Zagreb, Croatia
3. Karlo Beljan, Faculty of Forestry, Zagreb, Croatia
4. Mario Komarčević, Faculty of Forestry, Zagreb, Croatia

Abstract:
Frequent natural hazards are usually regarded a result of evident climate change. A representative example of such hazard was the ice rain that stroke forest area of Gorski kotar, Croatia in 2014. causing an ice break of varying intensity. In the year 2015. measurement and estimation of tree damage was performed on a subsample of field plots from National forest inventory. Of total 313 plots in beech-fir forests of that region 20 were chosen for damage estimation. Sample included managed forests and also protected area of Risnjak National park. Measurement was consistent with the NFI methodology and complemented with additional measurements in order to enable future monitoring of the tree damage and recovery. Plots within the protected area are left to the natural processes while the rest plots are subject to present and future forest management activities. Several variables were assessed for each tree on a sample plot – position, inclination, crown and trunk damage, previous damage. Description and analysis of the state of damage by tree species, stand and management factors was done based on field data. Results show the significant damage from the ice storm. On the estimated area of about 50 000 ha affected by storm, half of the trees had a broken tip, and about one quarter of standing stock are trees with crown damaged more than 50%. It is estimated that 21% of standing volume is irreversibly damaged and those trees should be removed from the forests. Broadleaves were damaged more severe than conifers, sycamore maple being the most affected species, and considering the diameter structure, thin trees were affected hardest. Influence of habitat (inclination, soil depth, rockiness) and stand characteristics (canopy closure, density) is also confirmed. Results indicate possibility of stand recovery aided by adequate forest management practice aimed at more resistant stand structures. Planned monitoring on permanent plots should track stand resilience and ensure improvement of future stand structures.

Key words:
ice break,forest damage,tree damage,Gorski kotar region,tree recovery,climate change

Thematic field:
Forest Menagement Planning

Date of abstract submission:
10.09.2017.

Conference:
Šumarska nauka u funkciji održivog razvoja šumarstva
25 godina šumarstva Republike Srpske