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从1989年起对挪威大约4000棵云杉的落叶和林冠颜色作了逐年调查。在1989～1995年间挪威云杉(Picea abies)的落叶和针叶褪色呈现显著稳定的增加。云杉的衰退似乎大多发生在挪威中部和南部。褪色程度每年都不一样可能是随不同气候条件而变化。1991～1995年间在挪威南部腐殖质pH<3.75的样地中观察到了显著程度的褪色。1989年以来所有年份中,在挪威南部大约10%的云杉样地上针叶褪色的出现率比其它云杉林高3～4倍。这些样地代换性镁的总量显著低于其它森林而腐殖质中N/Mg比率却显著高于其它森林。随着森林土壤污染负荷增加,有相对明显的镁含量降低和氮含量增加的趋势。目前它们对森林生态系统的影响还不确定。但是,从长远来看,连续的土壤酸化和氮沉降将肯定使森林土壤当前的格局恶化且最终使对森林的潜在伤害效应增强。
From 1989 onwards, a yearly survey of the deciduous and canopy colors of some 4,000 spruce trees in Norway was conducted. Deciduous and coniferous fading of Norway’s spruce (Picea abies) showed a significant and steady increase from 1989 to 1995. The decline of spruce appears to mostly occur in central and southern Norway. The degree of discoloration varies from year to year and may vary with different climatic conditions. A significant degree of discoloration was observed in the plots of Humus pH <3.75 in southern Norway from 1991 to 1995. In all years since 1989, the incidence of needle-leaf fading on about 10% of spruce fields in southern Norway is three to four times higher than in other spruce forests. The total amount of substitutional Mg in these plots was significantly lower than that of other forests while the N / Mg ratio in humus was significantly higher than that of other forests. With the increase of the pollution load of forest soil, there is a relatively obvious decrease of magnesium content and the increase of nitrogen content. Their current impact on forest ecosystems is uncertain. However, in the long run, continuous soil acidification and nitrogen deposition will surely aggravate the current pattern of forest soils and ultimately enhance the potential for damage to forests.