DIGITALNA ARHIVA ŠUMARSKOG LISTA
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ŠUMARSKI LIST 3-4/1963 str. 42 <-- 42 --> PDF |
4. Intensity of the height increment is strongest in the first year after the felling, and it amounted on an average to 57-9 cm. reckoning after the highest shoots However, all the highest shoots of the first year do not remain permanently the highest ones, but in the course of two or three years they are surpassed by others. 5. In the course of the first ten years we can distinguish the following developmental phases: a) the first phase ending in the third to fourth years, at the end of which there takes place a differentiation between those shoots that have and those that have not terminated their increment in height. As the limiting height was found the height of shoots with ca. 40 cm., and rounded to 43 cm. (one-third of breast height). In the part of the lowest shoots the stagnation of height increment occurs in the lowest shoots (of 10—20 cm. height) already in the first year, and also after the first growing season even when they are not more heavily shaded. b) the second phase terminates with the ceasing of height increment also in the part of shoots being higher than 43 cm. This phase is terminated in the seventh year, and as the limiting height can be taken the height of shoots of 100 cm. c) the third phase is the phase in which occurs the most intensive height increment of the highest shoots. In the forest of »Kaočina gaj« it was especially conditioned by abundant rains in the June 1959. In the tenth year was observed the dying away of a ´greater number of shoots having the height under 100 cm., i. e. there occurs a self-thinning through the dying-away of lower shoots. 6. Reduction of the number of shoots within the clump before the tenth year did not effect positively on the height increment irrespective of the density of clump (number of shoots) and the method of intervention. 7. The heights are computed on the basis of only the highest shoots, viz. the shoots being significant for the development of the stand. The average heights of all the shoots are of interest only from the biological standpoint in the course of the first and second years, because of giving a picture of the whole biological activity of the stump and the clump of shoots respectively in the above-ground part. 8. The average diameter in the height of 43 cm. (in the eleventh year) amounted to 1-72 cm., the average height of the same trees having been 143-4 dm. (established only in one experimental plot). 9. Arbutus developed in an analogous manner as the evergreen Oak but more slowly. Eleven-year-old trees higher than 100 cm. (on the same plot as the evergreen Oak in the aforegoing polntj achieved an average height of 128-6 cm., and an average diameter (in the height of 0-43 m.) of 1-4 cm. 10. Phyllirea grew luxuriantly new shoots, but their differentiation in height was poor. What is more, in the fifth year there occurred a drying-up of tops of the highest shoots to be kept on also in the years following. 11. With regard to the luxuriancy of clumps and thus the ability to produce the crown closure the most valuable is the evergreen Oak. After it follows Arbutus, and in the last place is Phyllirea. 12. By this experimental plot it was possible to obtain the answer as to the value of, regeneration (resurrection) cutting in degraded macchias. Such a felling is useful, viz. one can expect better shoots only on better sites. According to a finding of foliar analysis, a clump arrested in growth possessed in its foliage a considerably smaller amount of Mg than the foliage of a well-developed clump and therefore it would be necesary to carry out systematic investigations in this direction. *) Ovaj prestaje djelovati 1952. g. i njegove poslove preuzima Institut za eksperimentalno šumarstvo Jugoslavenske akademije :znanosti i umjetnosti u Zagrebu, a kada je i ovaj ukinut (1955. g.) Institut za šumarska i lovna istraživanja NR Hrvatske u Zagrebu. 2) 1. Ing. V. Pleše: Regeneracija makije i pseudomakije na Kozjaku, Split 1952.; |