Variation in vessel element size and tissue proportion in three Iraqi oaks

Abstract

The percentage of wood elements and the variation of vessel element dimensions were studied in the wood of three oak species (Quercus aegilops, Q. infectoria, and Q. libani) growing in the native forests of Iraq. The volume percentages of wood vessels in these three sepecies were 22.3 for Q. Libani, 35.4 for Q. infectoria and 34.1 for Q. aegilops. The percentages of fibres were 55.8, 54.6, and 52.3 for the three species respectively. The vessel element length was 0.11 mm for the three species while the diameter ranged from 15.62-16.30 /Lm. The dimensions of vessel element were not consistent in their change with height or distance from the pith, increasing in Q. Libani and Q. infectoria, while a consistent decrease in vessel element length in Q. aegilops was noticed.