The pH and structure of the needle surfaces of scots pine and norway spruce seedlings after acid precipitation : Air Pollution and Forest Decline. 14th International Meeting for Specialists in Air Pollution Effects on Forest Ecosystems

1989

S. 535-537

3 Abb., 2 Lit. Ang., En, Zfsg. En

Unselbständiges Werk

200034840

The effects of simulated acid precipitation on the pH and the structure of needle surfaces were observed ofter irrigating Scots pine and Norway spruce seedlings with acid rain of pH 3 and pH 4 and with clean water of pH 7. The seedlings were irrigated from mid-August to mid-October in 1986 and from mid- continuing in 1988. A dry control without watering ws also included in the study. Significant seasonal changes in the pH and epistomatal wax structures of Scots pine and Norway spruce needle sufaces was found to rise gradually and with statistical significance during the experimental period. The pH of the current needle surfaces was found to rise gradually and with statistical significance during the hardening time from mid-August to mid-October in 1986. The pH of the needle durface of the pH3 treated Norway spruce seedlings was lowest and that of the dry control needles highest from October to January. The amount and condition of crystalline wax structures in the stomatal area of the needles highest rom October to January. The amount and condition of crystalline wax structures in the stomatal area of the needles was found to decrease rom June to October and after winter, but a statistically significant difference between the crystals were observed on the surfaces of the pH 3 treatment needles.