DIGITALNA ARHIVA ŠUMARSKOG LISTA
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ŠUMARSKI LIST 11-12/1973 str. 13 <-- 13 --> PDF |
Summary COMPARATIVE INVESTIGATIONS ON OPTIMAL SPACINGS OF SCOTS PINE (PINUS SILVESTRIS L.) AND EASTERN WHITE PINE (PINUS STROBUS L.) IN INTENSIVE CULTURES Opinions in our forestry practice are at variance as to the number of plants to be planted per unit of area when establishing intensive cultures of conifers. The concerns especially Scots Pine (Pinus silvestris L.) and Eastern White Pine (Pinus strobus L.), which arc very frequently used for the establishment of plantings and have characteristic to develop a strong crown. In connection with these problems there were established on the territory of the SR Croatia one experiment with Scots Pine and another with Eastern White Pine. The experiment with Scots Pine was laid out in the spring of 1966 (on pseudogley) and with Eastern White Pine in the autumn of 1966 (on lessive terra rossa). In both species the same spacings were applied, viz.: lxl , 1,5 X 1,5, 2x2 , 2,5 x 2,5 and 3x 3 m. The experiments were established according to the block system with randomly distributed variants in four replications. In the autumn of 1966 — four and three years respectively after the establishment — the first measurements were taken in the experiments. Measured were the total height of plants (h), the length (I) and diameter (d) of the terminal shoot (secondary or »lammas« growth in 1969). On the basis of the length and diameter the volume of the terminal shoot (v = d2 . 1) was computed. On the basis of the results obtained for the total height of plants and the differences among the employed variants, it was shown that the effects of spacings in the past period were not decisive for the height growth in the experiments (F-test 0,05). Performed was Duncan test (0,05), and it was shown that a 2 x 2-m spacing was more suitable than spacings 1,5 x 1,5, lxl , and 2,5 x 2,5 m, and that a 3 x 3-m spacing is preferable to spacings 1,5 x 1,5 and 1 x 1 m. Investigations are to be continued. |