Utjecaj intenziteta prorjeda na rast azijske bukve (Fagus orientalis Lipsky) u plantažama u Trabzonu na sjeveroistoku Turske

Abstract

In this study, the effects of first thinnings having different intensities in oriental beech (Fagus orientalis Lipsky) plantation areas were investigated in terms of diameter and height growth of trees. Sample plots were chosen from oriental beech plantation areas which are within the boundaries of Maçka–Yeşiltepe and Vakfıkebir districts of Trabzon province, Turkey. With removing of 0%, 10%, 25% and 40% of basal area in a hectare of stands which are in sapling stage, sample plots were established by applying thinnings which are in four different intensities (control, light, moderate, strong). After the thinning applications, basal areas were calculated by measuring diameters and heights of trees in established sample plots in order to reveal stand growth. The effects of thinnings were revealed related to some stand characteristics (average diameter, basal area, average height, relative diameter increment, etc.) and determined chosen trees. The effect of thinning intensity on average diameter, basal area, and volume values is statistically important in every two plantations. 2-year results showed that thinning increased the diameter increment significantly, and the increase in diameter increment was positively correlated with the thinning intensity in both experiments. Moreover, increments of diameter, height, basal area, and volume were higher in Maçka-Yeşiltepe experiment than in Vakfıkebir experiment. But, the values of moderate and strong thinning intensities applied in Vakfıkebir were close to each other. When all the results are evaluated, application of strong thinning intensity for Yeşiltepe sample plot, the moderate thinning intensity for Vakfıkebir sample plot is seen appropriate by us in terms of both stand development.

Evaluation of the effect of different thinning types on dendrometric parameters and subsequent spontaneous growth in a beech-oak-linden stand

“…At the first stand, the plot with heavy thinning had a similar thickness to that of the reference plot, and at the plots with light and medium thinning, the thicknesses were even smaller than at the reference plot. At the second stand, the thickness of the beech in the plot with heavy thinning was smaller than that in the reference plot; there was no difference in the thickness between the reference plot and the one with light thinning; the thickness in the plot with the medium thinning increased, compared to that in the reference plot (Usta et al 2019). Juodvalkis et al (2005) state that the thickness after thinning in deciduous trees does not increase in comparison with the trees in the reference plots if thinning is very heavy.…”

“…Various reactions to the thinning performed were observed by Usta et al (2019), who conducted three types of thinning in two young beech stands, and from their results, it is obvious that there were very different thickness responses. At the first stand, the plot with heavy thinning had a similar thickness to that of the reference plot, and at the plots with light and medium thinning, the thicknesses were even smaller than at the reference plot.…”

“…the lightest thinning) increment curves were less steep than the others. The reason for the accelerated thickness increment of the remaining trees should be the greater availability of light, water and nutrients (Usta et al 2019). As the trees grow and fill the above-ground and below-ground layers, the availability of light, water and nutrients decreases, and therefore the thickness increment decreases again (Meinzer et al 2011).…”

“…In scientific works, the effect of thinning on the height of oak, beech or linden is seldom described and the results contained in the few available works differ. For example, at one beech stand, there was a positive reaction of the trees after medium and heavy thinning, and at the other, there was none (Usta et al 2019). Ciancio et al (2006) also describe a positive effect of thinning on the height of beech trees.…”

“…The reason for Figure 1. The location of the research plot this phenomenon is an increase in the availability of light, water and nutrients immediately after thinning, and their reduction again by subsequent filling of the above-ground and below-ground layers by the remaining trees (Meinzer et al 2011;Usta et al 2019).…”