Effects of acid and ozone on the nutrition Status of clonal norway spruce after fourteen months of treatment in environmental chambers : Air Pollution and Forest Decline. 14th International Meeting for Specialists in Air Pollution Effects on Forest Ecosystems

1989

S. 503-506

5 Tab., En, Zfsg. En

Unselbständiges Werk

200034800

Five clones of three-year-old Norway spruce (Picea abies (L.) Karst), planted in 1985 in to different soils, were exposed in 1986 and 1987 to two contrasting regimes of acid mist and ozone: "pH 3.0 refers to treatments with acid mist (sulfuric acid plus sodium solfate) of pH 3.0 plus elevated ozone leels of 40 - 50 ppb with episodes up to 170 ppb; "pH 5.6" refers to tratments with mit of pH 5,6 plus reduced levels of ozone of 20-25 ppb (ozone produced from pure oxygen). After 14 months of duplicated treatments the twigs of all trees (8-16 replicates) were collected with respect to the different needle age classes, and aliquot of the different needle age classes, and aliquots for the needles were analysed for the following elements: Ca; Cu; Fe; K; Mg; Mn; N; P; Zn. Highly significant effects of clone, soil, needle age and treatment as well as interactions between these factors were affirmed by analyses of variance. The comparison of the elemental concentrations and the elemental contents of the total needle biomass per tree indicate that significant reductions of the elemental contents per tree, induced by ozone plus acid mist, are due to needle loss and a reduced accumulation of biomass rather than to enhanced losses by leaching. Hence, the treatment-dependent losses of elements, as determined earlier by direct analyses of the leachates, are considered to be of minor physiological importance as long as the trees are able to compensate for these losses. As natural acid mist contains a series of compounds (e.g. NH4+) triggering leaching even more than sulfuric acid, our results are not necessarily in contradiction to the consequences of leaching from foliage found by other authors.