[en] One of Sweden's most intensively monitored experimental forest-fertilization sites is located in the county of Haerjedalen in the northern region of the country. The site was treated with different doses of nitrogenous fertilizer three times between 1967 and 1981, and final felling of the site was carried out in 1987. When the site was inspected 11 years after final felling - 17 years after the latest treatment - clear signs of the effects of fertilization were in evidence: * The treated area contained significantly higher levels of humus, carbon and nitrogen than the untreated control plots; * The plots that had been treated with very high dosages of N-fertilizer exhibited significantly higher nitrogen mineralization and nitrate formation - which was not the case on plots given smaller dosages that were more in line with those used in operational fertilization. In earlier studies on this experimental site, heavy nitrogen leaching was observed from those plots treated with high dosage levels. In theory, this should lead to reduced levels of exchangeable calcium, potassium and magnesium base cations in the soil. However, no evidence was found of this