DIGITALNA ARHIVA ŠUMARSKOG LISTA

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ŠUMARSKI LIST 11-12/2009 str. 38 <-- 38 --> PDF |

S.Andrašev, M. Bobinac, S. Orlović: DIAMETER STRUCTURE MODELS OF BLACK POPLAR SELECTED ... Šumarski list br. 11–12, CXXXIII (2009), 589-603 height, represented by standard deviation (sd). Its change depending on plantation age, with a high value of the correlation coefficient (R=0.74), points to the differentiation process of the trees in the plantation. The parameters of the Weibull diameter structure model (a,b,c) of the study poplar clones, according to the analysis of variance F-ratio, decrease till the age of 8, and then they increase.Asimilar F-ratio trend was shown by the stand quadratic mean diameter (dg) and total basal area per hectare (G), with the minimal F- ratio at the age of 12.As the parameters describe the internal plantation structure, the earlier change in parameters compared to growth elements indicates the growth changes in the trees of different categories (diameters), which enables the adequate evaluation of the plantation state and future development. The quantification of similatities and differences in the location, scale and shape of diameter structure during the development of the plantations of different clones contributes to the advanced study of plantation development and can be applied in the construction of the growth model of selected clones, and their production differentiation. The assessment of the effects of clone and plantation age on diameter structure enables a more reliable construction and estimation of the future structure, and also its incorporation in growth models. 6. CONCLUSIONS – Zaključci Based on the research of 20-year old test plantation consisting of several newly selected clones of black poplar, Section Aigeiros(Duby), which are either registered or are in the selection procedure, we can conclude as follows: – there are significant differences in growth elements (dg, G) between individual clones in the test plantation at the end of the study period of 20 years, which provides the basis for their production differentiation; – periodical measurements of diameters at breast height showed different growth of the clones depending on the age: in the initial period of development, the clonesPopulus deltoidesBartr. ex Marsh. (S , 6-7 NS , PE 19/66, NS , S ) developed more inten 1-3 11-8 6-36 sively than the clone Pannonia (Populus×euramericana( Dode) Guinier), and later on Pannonia had a more intensive growth, while the clones ofP.deltoidesBartr. ex Marsh. showed the differentiation; – theWeibull distribution model is suitable for diameter structure modelling of the study poplar clones at different plantation ages, and the applied method of predicting the location parameter (a) of theWeibull distribution model showed that in 90.6 % of the study sample, the parameter “a”ranged between 50 and 90%, and in 52.4% “a”ranged from 80 to 90% of the minimal diameter; – with higher plantation ages, location parameter (a) and scale parameter (b) also increased with small oscillations, which was confirmed by the significance of the correlation coefficient of 0.71 and 0.73 respectively. This was shown by the shift of the curve of diameter structure model to the right, towards larger diameters, and in a wider range of diameters at breast height with a lower relative frequency of the modal degree; – in the initial period, F-ratio of all three parameters of theWeibull diameter structure model decreased and reached the minimal value at the age of eight, and the predominantly increasing trend started at the age of twelve, which points to the changes in diameter structure of the clones depending on the age; – the constructed models of poplar clone diameter structure show the clone grouping in two groups, which was confirmed by the non-parametric Kolmogorov- Smirnov test, the analysis of variance test, and LSD test for the percentage of the number of trees with diameters at breast height above 40 cm. This emphasises the possibility and the need of their grouping in the definition of management procedures. 7. REFERENCES – Literatura Anderson,T.W.,D.A.,Darling,1954: ATest of goodness-of-fit. Journal of theAmerican StatisticalAssociation, 49: 765–769,Alexandria, USA. Andrašev,S., S.Rončević, M.Bobinac,2003: Uticaj gustine sadnje na debljinsku strukturu klonova crnih topola S 6-7 i M-1 (SekcijaAigeiros (Duby)). Glasnik Šumarskog fakulteta, 88: 7–16, Beograd. Andrašev,S., M. Vučković, S.Rončević, M. Bobinac,2004: Mogućnost modelovanja debljinske strukture i izračunavanje zapremine za sada klonova crnih topola. Glasnik Šumarskog fakulteta 90: 37–51, Beograd. Andrašev,S., M. Vučković, S.Rončević, M. Bobinac,2006: Modeli rasta stabala crnih topola sekcije Aigeiros (Duby). Glasnik Šumarskog fakulteta 94: 81–90, Beograd. Andrašev,S., 2008: Razvojno proizvodne karakteristike selekcionisanih klonova crnih topola (sekcija Aigeiros Duby) u gornjem i srednjem |