Wood moisture of the rough-bark poplar

The content of wood moisture is one of the evaluation criteria of the poplars’ viability. The purpose of the study is to evaluate the nature of relative moisture distribution in the wood of the poplar trunk cross-section and to identify the content of moisture dependent on morphometric characteristics of the tree. The studies on the content of wood moisture were conducted on the tree trunk samples taken at the height of 1,3 m. from the ground. The samples were obtained by coring both the northern and the southern sides of the tree. The content of wood moisture was measured in dry particles of 10 mm long by gravimetric method. The average content of wood moisture in the rough-bark poplar is 55 %. The average content of moisture in sapwood is about 44 %, and the average content of wood moisture in the heartwood area - 58 %. The average width of the sapwood is 4,7 cm. (25 %). The content of moisture in sapwood area is moderately variable and depends on the diameter and the age of the tree. The amount of distributed moisture depends on the size of the sapwood cross section. The difference can reach 45 %. The severity of necrosis effect on the content of wood moisture in the sapwood cross section depends on the diameter and category of the tree. The width of the poplar sapwood is characterized by high variability. It depends on morphometric characteristics of the wood. We distinguished three schemes of moisture distribution along the radius of the tree trunk: 1) gradual increase of moisture from the cambium to the heartwood section (20 % of the trees); 2) even distribution of moisture along the cross-section of the tree trunk (13 % of the trees); 3) high level of moisture on the outer centimeter of the sapwood trunk. The difference in the level of moisture along the boundary of the sapwood and heartwood timber area can reach 30 % (60 % of the trees).