Dunántúli tölgyek gesztesedési folyamatai

The two main parts of a log, sapwood and heartwood, have different properties. With regard to utilization in the wood industry, the latter is of great importance because of its higher durability and better mechanical properties. In case of wood species with colored heartwood, this fact is considered through the removal of the sapwood. This is especially true for oak, which is one of the most valuable dominant hardwood species in Hungary that prefers full sunlight and has a wide range of utilization. More than one third of the domestic wood volume consists of oak species. The heartwood formation process of oak – just like in any other wood species – is influenced by many factors. Perhaps the most important is the genetic features of the tree, namely the wood species. There are several external determinative factors, however, like the growing conditions and ecological circumstances (geographical situation, climate, site, hydrology, etc.). Unfortunately, the effect of the circumstances is usually not taken in account despite its high importance. In terms of the quality improvement of oak stands, the examination of the relationship between heartwood-sapwood ratio and environmental factors can be a new approa ch. Increasing heartwood ratio, among numerous other benefits, primarily results in economic asset, therefore the investigation of the heartwood formation rate cannot be neglected. To confirm this statement, the present study demonstrates that the geographic situation of forest stands is an impor tant factor in the heartwood formation process

Xylotomic similarities and natural habitat of the fossil remains of Bükkábrány

The unique remains of a 7.2-million-year-old forest consisting of Bald cypress and Coast redwood were found in the area of Bükkábrány in County Borsod-Abaúj-Zemplén of Hungary. The trees of the fossil remains comprising 16 stems, which were discovered in a lignite mine, were standing in their original locality, and preserved their original cellular structure. No petrification occurred, which is general characteristics of wood remains preserved for millions of years. What makes the findings unique is that they make it possible to carry out the traditional histological examination of the intact wood structure. The results of light and electron microscopic investigations definitely proved that in addition to Bald cypress, the wood species of the ancient forest remains also included Coast redwood. Today, the natural habitat of Coast redwood is definitely in North-America, but millions of years ago, they were also present in Europe including the Carpathian basin. The xylotomic analysis has unambiguously revealed that two of the investigated five trunks are Bald cypress (Taxodium distichum) or the already extinct Taxodioxylon germanicum, while the other three trunks are Coast redwood (Sequoia sempervirens) or a member of the already extinctfamily, the Sequoioxylon sp