[On the Distribution of wood extractives in the stem of Sweet Chestnut (Castanea sativa Mill.) and Oak (Quercus infactoria Oliv.)]

Wood extractives divided into primary and secondary wooden extractions. The primary wooden extractions consist of materials which exist in every wooden species like carbohydrate, lipid, starch, and amino acids while the secondary wooden extractions consist of materials which available in certain wooden species like phenol components, chinonats, terbinats, tannin, etc. As the wooden extractions affect biological, physical, and chemical behavior of wood and wood based panels, which affect in its turn in many chemical, mechanical, and physical features. As a result it definite their ability and possibility their usages. In addition to there are not so many researches which studied the distribution of wooden extracts (primary –secondary) in widen leaves wooden species (Hard wood species), where as they are rich in conical wooden species .So we found that the importance as a main goal for this thesis is to study the distribution of the wooden extractions (primary and secondary) in trunks for the two wooden species of the sweet chestnut and oak as the following: Determination the rate of wooden extraction (primary and secondary) with the height of the taken sample in the stem and in the cross section of stem from the bark to the center for both studied species. The study was about three approximate by the age of sweet chestnut trees which were marked and symbolized with C1, C2 , C3 and three trees of oak Q1 , Q2 , Q3 in Matta's forest of Mhelba region in Drekeesh area, where they were taken many wooden pours from three section of different height from their stems. First section of surface of soil (0.5 m )L , second section from the height 1 – 1.5 m (m) , third section 2 -2.5 m (h), then pours were put in paper bags which recorded on them the symbol for both the tree and the taken sample , after that they were dried by air , then every pour divided to heart wood close to center H1 and other one far from center H2 , sap wood S ,then every part was crashed separately into wooden particles with dimension (0.8mm) ( wooden sawdust for extraction ) by using lab mill TR20 after that wooden particles in each part were put in paper bags which were written on them by symbol refer to tree and the height of the taken pour and the sort of wood (Ethanol/Cyclohehane extract) (Fengel and Przyklenk, 1983), (Lelis, 1995) , besides primary wooden extraction (hot water extract) \{ (lelis , 1995 , Hameed ,2000) ( Hameed, 2007) \} , and this research was summarized by the following results: - 86 - 1-For the first time and by this research the rate of the (primary and secondary)wooden extraction with the height of the taken sample were determined in addition to a cross section of the bark towards the center(pith) for both wooden types the sweet chestnut and oak. 2-Decreasing in averages of the secondary wooden extraction (Ethanol/Cyclohehane extract) with the height of the taken sample in stem for both wooden types sweet chestnut and oak, and this could be functioned as a result in manufacture of the different quality sorts for the saw wood and chip – boards and varied in their physical, mechanical, chemical, and biological properties to control their uses, this result also gives scientific justification to what kaaka (2003) registered the shift of mechanical and physical features for the boards of manufactured saw wood of sweet chestnut with the height of the taken sample for the stem . 3-Increasing in averages of the secondary wooden extraction (Ethanol/Cyclohehane extract) in the across section for the stem from the bark towards the center (pith) for both wooden species sweet chestnut and oak. 4-The obvious abstract superiority of the averages of the secondary wooden extraction (Ethanol/Cyclohehane) in the heartwood compared with the averages of the secondary wooden extraction in the sapwood for both wooden species sweet chestnut and oak, this what explained the physical , mechanical , chemical , and biological specifications which the heartwood differ from the sapwood . 5-The obvious abstract superiority of the averages for the primary wooden extraction (the hot water extract) in the sapwood compared with the averages of the primary wooden extraction in the heartwood for both wooden types sweet chestnut and oak , this what explained the bad physical , mechanical , chemical , and biological properties for the sapwood compared with the heartwood . 6-This research registered the nonexistence of the abstract differences among the percentage averages of the primary wooden extraction (the hot water extract) for both sapwood and heartwood (close and far from pith) with the increasing of the height of the taken sample in the stem for both wooden species sweet chestnut and oak, as this result is translated in applied reality that the dictum of the determination of the physical, mechanical, chemical, and biological features for both studied species which base on its content of the Ethanol/Cyclohehane extract. 7-The trunks for both wooden species sweet chestnut and oak which were taken from the same location and approximate by age were the same in their contents of the secondary wooden extraction (Ethanol/Cyclohehane), in addition to primary extraction (hot water extract) and these extractions have applied importance to control the investment of the same aged trees in the same location by appropriate cutting rotations and this case ease the process function of the correct use in the industry and constructional works since their woods are same in physical, mechanical, chemical and biological properties.