Structural Elements and Morphological Characteristics of Pedunculate Oak (Quercus robur L.) in Young Even-Aged Stands of Spa？va Forest

Sa？etak Background and Purpose: Croatian Forest Research Institute and Croatian Forests Ltd., Zagreb, have in 2010 jointly proposed a scientific experiment on permanent experimental plots called “The Impact of the Intensity of Silvicultural Tending on Pedunculate Oak Dieback”. The basis for setting up experimental plots were the results of the analysis of surface structure of pedunculate oak (Quercus robur L.) stands of Spa？va Forest and its projection area for the next 140 years, and the related issues of regeneration of old and tending of young stands in conditions of increasing climate change. In the future this will present a major problem for forestry practice in silvicultural operations, both in terms of workers and materials. Materials and Methods: The experiment was conducted in the area of Forest Administration Vinkovci, Forest Office Vinkovci, Management Unit Kunjevci, in three subcompartments of different age (10, 15 and 20 years) where different intensities tending operations of cleaning were conducted. A total of 20 plots were established by using the already established network of silvicultural lines and paths, while the position was recorded by a GPS device. On each plot 30 pedunculate oak trees were permanently marked (600 trees in total). Tree selection was based on spatial and phenotypic criteria. Results: The initial measurement on permanent experimental plots shows unsatisfactory number of pedunculate oak trees along with the high number of common hornbeam trees. The overall basal area has a tendency of continuous growth in relation to the age of experimental plots. The value of crown length in relation to the total height of pedunculate oak trees is 74.3% in subcompartment 32A, 53.5% in subcompartment 34 A, and 54.3% in subcompartment 38A. Trunk length, i.e. trunk purity also increases with age; in subcompartment 32A on average it amounts to 1.35 m, in subcompartment 34A to 3.28 m and in subcompartment 38A to 4.85 m. Conclusion: After conducting periodic surveys of the established plots by the year 2020 enough data should be collected whose processing, analysis and interpretation would provide guidelines for improving the future management of young pedunculate oak stands