DIGITALNA ARHIVA ŠUMARSKOG LISTA
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| ŠUMARSKI LIST 5-6/1988 str. 44 <-- 44 --> PDF |
The beech stands belong to bioindication net (16 x 16 km) established in 1987. within forest damage sruvey on the territory of Croatia. Spruce plantations are mainly located within and in a wider area which is defined by the investigated bioindication plots of beech stands. On the basis of the results it can be concluded that beech stands and spruce plantations on north-western Croatia are influenced by imissions of air pollutants. Beech stand on Velebit montain is to greatest extent subjected to heavy metals input. In this stand a very significant defoliation is registered, while in other four beech stands the present conditions of aiir pollution is not reflected in visual simptoms. Among the investigated spruce plantations only two had normal, natural sulphur content in needles. In seven plantations sulphur concentrations were somewhat higher, when the negative S02 influence is not yet expected. The last three plantations had S-cocentrations up to the point where harmful S02 influence can be expected. The efficient growth of spruce plantations is highly influenced by nitrogen and phosphorus nutrition. Nutrition by other nutrients is very favourable. Very high iron concentration and little of manganese were determined in spruce needls in immediate vicinty of Sisak Ironworks. |