Current issue: 53(4)
Under compilation: 54(1)
Fertilizer factory has been found to be harmful to the surrounding area through its fertilizing effect, mainly due to nitrogen compounds in the form of NOx and ammonium. In this study, pH, K, Ca and Mg contents in the humus layer were monthly monitored around a fertilizer industry in Oulu, Northern Finland, in 1975 and 1976. In addition, nutrient analyses were made in the leaves of Vaccinium vitis-idaea, V. myrtillus and Empetrum Nigrum.
The calcium, magnesium and potassium present in the emission of airborne fertilizer dust brought about an increase of the nutrient content of the surface top soil humus compared with the control samples. The nutrient contents of dwarf shrub leaves increased near the industrial site as compared with the controls. The potassium contents of Vaccinium myrtillus and Empetrum nigrum were exceptionally high. The results of this pilot study show that the overfertilization must have had an increasing effect on the nutrient status changes in the forest environment.
A forest damage was detected in spring 1931 near electro-chemical factory in Imatra in Eastern Finland. It was deduced that it was caused by a gas discharge from the factory. A survey was made to describe the damages. Forests in the damaged area of five hectares were Scots pine (Pinus sylvestris L.) dominated and 60-80 years old. According to the factory, the exhaust gases contained 0.4 mg chlorine per liter. In addition, chlorate containing liquids evaporated thorough the chimney, which seemed to have been the main cause of the damage. The chlorates may have concentrated in the snow covering the trees during the winter. The Scots pine trees had lost all the needles in spring, but grew new needles in the summer. In some trees the new needles were few or undeveloped. Some mild damages were noticed in pine and Betula sp. during the growing season. Forest edges and trees higher that the other trees were worst damaged. Pine was most sensitive to the emission. Pine weakened by the gas damages were attacked by insects, the most important being Pissodes sp. The secondary insect damage is likely to kill the surviving trees. The dying pines should be removed only if it is necessary to prevent the spreading of insect damage. The trees may hinder the spreading of further gas emissions. In future, other tree species should be preferred over pine.
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