Aging and fossilization of wood and its components

摘要: Aging of wood begins with the cutting a tree. The subsequent changes substance proceed very slowly and depend on environmental conditions. In hot, dry desert climate wooden objects cellulose textiles are preserved for several millenia, whereas their degradation is accelerated by conditions which favor attack microorganisms. Two under aging processes take place can be distinguished: a) aerobic as prevailing in buildings, sculptures etc.; b) anaerobic valid items buried ground or submerged water such foundation pillars, ships etc. Submersion underground embedding initiate slow process fossilization cell wall transformed into highly condensed compounds (coalification) substituted minerals (silicification). various components subjected to different kinds conversion. polysaccharides disappear seem more sensitive than lignin. Although resistant, lignin converted chemically its structure differs increasingly from original state. Even extractives may survive millions years.