DIGITALNA ARHIVA ŠUMARSKOG LISTA
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| ŠUMARSKI LIST 1-2/1966 str. 56 <-- 56 --> PDF |
Schönbach (1956) je ispitujući sadržaj celuloze i zapreminsku težinu roda Populus pronašao da postoje genetski uslovljene razlike zapreminskih težina. Zaključak: Ispitivanja pokazuju da je najveći apsolutni porast dužine drvnih vlakana stabala bele vrbe bio u dobi od 10—20 godina, posle čega su dužine i dalje rasle do 30 godina, mada ne tako intenzivno, da bi posle počele opadati. Najveća proseena dužina drvnih vlakana bila je u 30., a najmanja u 10. godini. Analiza varijanci nam pokazuje da su signifikantne razlike dobijene za stabla-predstavnike, što ukazuje da u prirodnim populacijama bele vrbe postoji genetska varijabilnost bar u pogledu toga parametra, tj. dužine vlakana. Summary VARATION OF FIBER LENGHT IN NATURAL STANDS OF WITHE WILOW (SALIX ALBA L.) Described are the results of investigations on 5 sample trees of White Willow (Salix alba L.) from the flooded area of the River Danube, near the town of Sombor. The sample trees were selected in the forest as »plus trees«. The main data about the sample trees are given in Tab. 1. Discs from each sample tree were cut at breast height (1,30 m), and at 3,30 m. height. The third disc was cut at heights varying from 5,80—8,80 m., (average 7,40 m.). Wood fibre samples were taken from the east side the discs and from the growth rings of 10, 20. 30 and 40 years age for each height. Both early wood and late wood fibres were examined. After maceration from every sample were taken at random 360 fibers on a average. Fibre length measurements were made by means of an A. O. Spencer microscope. Examined were a total of 27,200 fibers ,the results of which are presented in Tab. 2. An analysis of the variance in factorial experiments has shown that the significant difference at 1%> level was obtained only for sample trees. Our results have shown that the longest fibres were formed at the age of 30 years, and were 1025,5 microns in lenght, while the shortest were formed at 10 years with 939,5 microns. The fibre lengths increase until 30 years, after which they decrease. The author concludes that within the investigated population of Salix alba I.. there exists genetic variability in respect of the fibre length. LITERATURA 1. Einspah r D.: Correlation between fiber dimensions and fiber and handsheet properties, Tappi, 4, 1964, New York. 2. Liese-Amer : Untersuchungen über die Länge der Holzfaser bei der Pappel Holzforschung, 11, 1958. 3. Scaramuzz i G.: Variazioni dimensionali delle libre nel fusto in Populus x euramericana cv. 1-214, Ente Cellulosa Carta, Roma, II, 1958. 4. Schönbac h H.: Untersuchungen über Cellulosegehalt und Raumgewicht von Pappelhözern im Rahmen der Züchtung, Wiss. Abh., 16, 1956, Berlin. 5. Zobe l B.: Breeding for wood properties in forest trees, Unasylva, 18, 73/74, 1964. 54 |