TYLOSES FORMATION AND THE STATE OF HEALTH OF QUERCUS-PETRAEA TREES INHUNGARY

In a 76-year-old sound and in a 77-year-old diseased trunk of Quercus petraea the number of earlywood vessels with and without tyloses were counted along a 1 cm tangential segment of the annual rings, in four d irections at four heights (0.16, 1.35, 12.0, 24.0 m). At all heights o f the sound stem, the percentage of earlywood vessels sealed by tylose s is low (2.57-4.13-5.94%). In the diseased stem, the percentage of ea rlywood vessels sealed by tyloses is higher (7.40-13.08-19.86%) than i t is in the sound stem. This demonstrates a decreased hydraulic capaci ty in the diseased stem. In both trees, the percentage of earlywood ve ssels sealed by tyloses increased from the stump (at 0.16 m trunk heig ht = 5.02%) upwards (at 12.0 m = 12.58%).