DIGITALNA ARHIVA ŠUMARSKOG LISTA
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ŠUMARSKI LIST 11-12/1990 str. 81 <-- 81 --> PDF |
3. Kraljić , B.: Što da se radi pri masovnom sušenju naših šuma u ZO Rijeka »Goranski list« br. 206/90. 4. Plavšić , M. Golubović , U.: Istraživanje sadašnje najpovoljnije sječne zrelosti u jelovim prebornim šumama. Zagreb, 1967. 5. S eh u Iz, H.: Oštećenje šume — kvalitet drveta. »Šumarski list« br. 6—8/1989. Comparative Investigations of Economic Consequences of the Dying Back of Fir Trees in Gorski kotar Summary Serious dying back of fir and beech forests in Gorski Kotar was noted as early as 30 years ago. It is caused by a moth attacking fir needles (Argyresthiafundella). Although this dying back was of a local character affecting only some areas in the Fužine forest district, in fact only some part of it, it was quickly and fairly successfully arrested by airplane apraying with appropriate preparations. However, the disease later on spread to larger areas in the district to such an extent that it began to cause concern not only among experts but also the public at large. The causes of the dying back of fir trees are being carefully examined and the first results indicate that they lie in acid rains or frequent rainless years, and even years without any snow, or perhaps in the present mode of management of these forests, but in the first place in thir overripeness for felling. Through the investigation now under way it will be possible to determine the causes of the dying back of fir stands. It is quite probable that the causes are complex and act synergically, so that they are investigated in this light. Without concerning ourselves with the causes, we investigated the economic consequences of the dying back of firs in Gorski Kotar and are presenting in this paper some of the results obtained. We carried out our investigations in fir-beech stands in the communes of Delnice, Čabar and Vrbovsko, which together have about 68,000 hectares (one hectare = 2.47 acres) of uneven-aged fir-beech forests of natural origin. Out of this total, about 5,200 hectares, or 8 per cent, is accounted for by a plant community of fir and a variety of fern (Blechno-Abietetum Ht), or I — C — 40 forest type. This type of forest on a predominantly silicate substrate ranks among the best kinds of fir-beech stands in Gorski Kotar. This growing stock averages about 450 cu.m./ha and its current-annual increment exceeds 7 cu.m./ha; about 83 per cent of the stand is accounted for by classes I and II, and the quality of firewood is first class. |