Influence of NO2 and SO4 as Well as of Acid Rains on the Structure of Needles and Wood Quality of Abies Alba Mill. Stands

1990

S. 75-81

10 Abb., 4 Lit. Ang.

Unselbständiges Werk

200094832

Influence of NO2 (0.25 1.1 hoch-1 . 300s hoch-1) and SO2 (0.21 . 1 hoch-1 . 7200s hoch-1) on the structure and durability of needles of Abies alba Mill. was investigated. It was proved that needles of Abies alba Mill. fall off from the stalks after remaining for 300s in NO2 and for 7200s in SO2. The zone of cutting needles from stalks was investigated by means of the electronic scanning microscope. Calcium pectinate appearing in the middle lamellae was oxydized by NO2. From NO2 and SO2 acid rains which damage most the white fir stands over 60 years old growing in mountainous areas are produced. Wood of the pith zone is young wood of inferior quality and wood of peripheral zone called mature one shows the highest technical quality. In the effect of dying of older trees the share of mature wood in the stem will decrease.