DIGITALNA ARHIVA ŠUMARSKOG LISTA
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ŠUMARSKI LIST 3-4/1996 str. 13 <-- 13 --> PDF |
S. Matić, M. Oršanić. I. Anić: NEKE KARAKTERISTIKE [ PROBLEMI PREBORNIH ŠUMA OBIČNE JELE ... Šumarski list br. 3^1 , CXX (1996), 91—99 - the occurrence of secondary pests which quicken the tree dieback; -aggressive beech expansion into the fir territory, especially in southern rocky expositions and southern edges of the fir areal, combined with artificially increased proportion of spruce-trees. All the factors mentioned above are contributing to the negative trends in the selection forest development in Croatia, the causes of which can be classified in three groups: a) The application of improper silvicultural measures, especially as to the felling cycle, the intensity and felling methods. b) The appearance of long dry periods in the global climate. c) Adverse impacts of acid rain, air, water and soil pollutants. Acting simultaneously, some of these factors cannot be influenced. We should therefore apply adequate silvicultural methods to form structures capable of overcoming the negative impacts. Key words: selection forest, structure, regeneration, felling cycle, normal structure. |