European oak (Quercus robur L.) is one of the most spread in Ukraine and the most productive forest species. However, forest plantations on sites after final felling have inferior stability and productivity as compared to the natural oak forest.
Despite many studies on natural oak regeneration, particularly in the Left-bank Forest Steppe, the improvement of measures to promote the natural oak forest growing remains relevant.
The aim of the study was to determine the most effective care treatment in the first years of oak stands growing by inventory the composition of 12-year-old oak stands.
Materials and Methods
The experiment was started in 2006. In the clear-cut of 2006 of the fresh ash & lime oak stand, the next year after European oak abundant fruiting (2005), forest plantations have been created with 2-year-old oak seedlings. In 2008 and 2009 mechanized care treatment using rotary corridor cutter RCC-1.5 (variant “RCC-1.5”) was carried out in one section of the experiment. In the second section, associated and secondary trees and shrubs were removed in oak bio-groups in autumn 2010 using brushcutter “Sekor” (variant “Brushcutter”). Care treatment was not carried out in control section.
Inventory of trees and shrubs was carried out in 2017 in three experimental sections:
– variant “RCC-1.5” – mechanized care treatment using rotary corridor cutter RCC-1.5 in 2008 and 2009;
– variant “Brushcutter” – removing of associated and secondary trees and shrubs using brush cutter in autumn 2010;
– control – without any care treatment.
Diameter and height of every tree or shrub were measured; the trees’ origin was pointed as seed artificial, seed natural or vegetative. Health condition was determined as alive, weakened or dead. Cross section and volume of each tree were calculated.
Results and Conclusions
The inventory shows the advantages of “Brushcutter” variant. In its section, the highest number (4,900 stems per hectare) and stock of oak (18.4 m3 ha-1), particularly of natural seed origin (3,050 stems per hectare and 7 m3 ha-1 respectively) have been assessed.
In section “RCC-1.5”, the oak stock was represented by trees of vegetative (57.1 %), natural seed (4.5 %) and artificial seed (38.4 %) origin.
In control section, 2,200 natural seed oaks per ha (75.9 %) and 700 artificial seed oaks per ha (24.1 %) have been assessed.
The part of ash stock was 11.9, 16.3 and 16.1 % in “RCC-1.5”, “Brushcutter” and control sections respectively. The highest number and stock of ash trees were assessed for “Brushcutter” section (2,100 stems ha-1 and 4.7 m3 ha-1respectively).
The main tree species (European oak and European ash) are represented by 4, 8 and 3 units in the stand composition in the variants “RCC-1.5”, “Brushcutter” and control respectively. The advisability of care treatment using “Brushcutter” variant is supported also by its one-time carrying out, while in the variant “RCC-1.5” the care treatment was repeated three years in a row.
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