DIGITALNA ARHIVA ŠUMARSKOG LISTA
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| ŠUMARSKI LIST 1-2/1973 str. 41 <-- 41 --> PDF |
16. Skorić A., Racz Z., Modrić A.. Kovačević P. (1963): Detaljno proučavanje glavnih tipova zemljišta Jugoslavije. Izvještaj Sav. fondu za nauč. rad za 1962. za područje SRH. Institut za pedol. i tehnol. tla, Poljoprivr. fakultet u Zagrebu. 17. Skorić A., Haj din Ž., Martinović J. (1967): Prilog izboru tala i agrotehničkih mjera pri intenzivnom uzgoju četinjača na Kordunu. III kongres JDZPZ, Zadar. 18. *** (1966): Osobine tala nekih lokaliteta na području Šumarije Duga Resa. Dokumentacija Jug. instituta za četinjače, Jastrebarsko. Zavod za pedologiju Poljoprivrednog i Šumarskog fakulteta u Zagrebu. Summary AN INVESTIGATION INTO THE PRODUCTIVITY OF HEATHER AND BRACKEN KOILS UNDER YOUNG CULTURES OF SCOTS PINE (PINUS SYLVESTRIS L.) IN THE REGION OF THE FOREST ENTERPRISE KARLOVAC Investigated was the thriving of some young cultures of Scots Pine on the soils of layered structure in the heather and bracken area of the Forest Enterprise Karlovac. The investigation was concentrated on a study of the physical properties of soils of layered structure and their influence on the growth of Scots Pine. Established was a great variability od depth of the surface loes-like layer of the soils investigated, which was especially marked in areas where soil groups II, III and IV were shifting. Further, through investigations the ecological importance of the aforementioned division into soil groups was confirmed. Thus young cultures of Scots Pine exhibited the best growing on the sample plots of soil group I, and then of group II and group III. This conclusion coincides with the established total amount of available water in individual profiles, as visible from Graph 8. When considering the results of investigations for individual profiles with respect to the established growth of Scots Pine according to the sample plots, we ought to take into consideration the difficulty about the proper choice of the characteristic profile. Thus, with a supplemental verification of the soil depth on plot 4, a considerably greater share of soil group III was established, which differed from the previous finding. A definition of the area with the share of soil groups II, III and IV in the pedological sense remains also further an open problem, because practically there are no surface signs with which the underground variability would correlate (Ćirić 1966). Although Scots Pine exhibits an equal growth in cultures established in the same soil group, individual localities possess certain definite specific. This could be explained in the first place by climatic differences of fairly distant cultures, such as Drenovac and Sadilovac (distance 63 km), and also by other differences (seed source, quality of planting stock, etc.). The weather conditions in individuals years also had a very marked effect on the height growth of Scots Pine. Thus in the markedly dry years 1968 and 1971 a noticeable diminution of the height growth in relation to other years of the investigated period was recorded. Because of the small number of investigations about the nutrition of Scots Pine, it is difficult to give a more precise estimate of the nutrient status of these cultures. More comprehensive investigations in this field were carried out by Fielder and Höhne (1967) in 6—10 year-old cultures of Scots Pine. In these investigations it was established that the nitrogen content in needles decreases with the diminution of humidity in the soil, and increases with the increase of nutrition. According to Heindsdorf (1967), fertilization with nitrogen positively influences the growth of Scots Pine cultures if needles contain less than 1.5—1.6% N. An approximately limiting value for nitrogen was also established by Kraus (1963). The investigated cultures in soil group I lie over the mentioned walue, while the concentration of nitrogen in the needles of Scots Pine in other two soil groups equals the limiting concentration. |