Conversion of Hight Forest of Turkey Oak Coppices : Results of an Experimental Trial Fifteen Years Later. Second Contribution

1987

S. 19-70

12 Abb., 3 Tab., 16 Lit. Ang.

Unselbständiges Werk

200033952

The growth rate of dominant shoots in a Turkey oak coppice, up to the age of 32, is here examined. A sample pf coppice shoots of the same crown class was collected in the following theses. Natural development of coppice; no silvicultural treatment was applied in this thesis (control plot); "transitory crop", originated from the conversion to high forest of the coppice at the age of 20. Three different intensities of thinning were tested (thinned plots). The analysis of the results points out that: Control plot. The volume increment in dominant shoots has a positive trend up to the age of 32; the increment course is composed of a series of distinct growth cycles; their importance is increasing on the age. The meaning of these cycles may be found in the natural competition and selection process among the trees; after the age of 20 the volume increment shows an increasing rate up to its culmination near the age of 30. In the whole period (20-30) the dominant fraction of the crop shows higher increment values than in the first one (1-20); the ageing period produces no senescence crisis and functional decay in the dominant shoots, but their increment shows a spontaneous acceleration, expression of the natural trend to high forest. Thinned plots. The first thinning improves the positive trend of the volume increment and increases its natural growth rate; the volume increment reaches its culmination in advance; there is an advantage to carry out the first thinning a few years before the age of 20, in the site quality tested; the intermediate thinning level (1800 stems per hectare), among the three tested, is the best one; a second thinning may be recommended about the age of 30.