Mikroskopische Untersuchungen an Fichtennadeln aus dem Schadgasausschlußversuch in Open-Top-Kammern am Edelmannshof

1997

S. 7-19

8 Lit. Ang.

Unselbständiges Werk

200104664

Air pollutant exclusion experiment with spruce trees at Edelmannshof: Physiological and biochemical investigations ; 16401, S. 7-19
; Nr. 164

Spruce needles from the trials with negative fumigation in the open-top-chambers at Edelmannshof were investigated microscopically. The collapsed mesophyll cells in needle cross-sections increased with age but showed no clear relation to the treatments. Within the chambers, a greater number of empty mesophyll cells indicated impact of sucking insects. The phloem structure showed no changes which xould be related to the effects of any mineral deficiencies. Epiphytes were much more abundant upon the needle surfaces within the chambers, regardless of the treatments, in comparison to the field samples. This indicates a probable effect of higher moisture within the chambers. In epidermal cells, calcium oxalate was more frequent in the filtered chambers than in the unfiltered and the field samples, pointing to lower leaching losses under clean air. In the mesophyll, intercellular calcium oxalate crystals increased with age but showed no treatment effect; interacellular crystals were similar in all treatments and all age classes, so that this criterium does not show any hints for a decrease in membrane permeability du to ozone.