DIGITALNA ARHIVA ŠUMARSKOG LISTA
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| ŠUMARSKI LIST 10-11/1959 str. 27 <-- 27 --> PDF |
RELATION BETWEEN THE DIAMETER INCREMENT OF WYCH ELM AND BEECH IN THE MANAGEMENT UNIT OF »RAVNA GORA« In the management unit of »Ravna Gora« (region of Gorski Kotar, Croatia) the frequency curve of the number of stems of Wych Elm (Ulmus montana With.) shows the structure of an even-aged forest, while the curve of the number of Fir and Beech stems shows more or less a selection forest structure. In stems of Wych Elm the culmination of the diameter increment occurs at a diameter b. h. of 45 or 50 cm. The minimum time of recruitment (»temps de passage«) amounts to 16.0 or 16.9 years. Beech stems display a higher increment than the stems of Wych Elm. The culmination of the diameter increment of Beech stems occurs in compartments investigated at 60 or 65 cm. d. b. h. The minimum time of recruitment amounts to 11.7 or 12.8 years. The reason for the fairly early culmination of the diameter increment is attributable to infestation by the Dutch Elm disease. Considering that the diameter increment of Wych Elm has an early culmination and that the most part of trees are infested it is not advisable to let them achieve dimensions larger than 90 cm. d. b. h. At the same time them appears the need to maintain and spread it naturally and artificially, because it has completely disappeared from a number of forest districts. The increment of Beech trees is a little lower than is indicated in Surić´s Tables. When examining the increment in Beech it is necessary to establish the diameter b. h. at which the culmination of the diameter or volume increment occurs. Beech trees should not be left growing over the culmination increment diameter. |