Effect of altitude on biometric, physical and mechanical properties of caucasian alder species (Case study in Savadkuh region)

The study of wood characteristics of a plant species at different altitudes has always been considered by researchers in this field because altitude is one of the most important and influential options on climatic factors (temperature, rainfall, sunlight and relative humidity) in an area. The aim of this study is to obtain accurate knowledge of changes in biometric, physical and mechanical properties of Caucasian alder(Alnus subcordata) species in different altitudes of northern Iran. In this study, three habitat altitudes above sea level in Savadkuh region, Talar basin in Mazandaran province, with the names of Shalimak series (1400 meters height), Miyana series (1000 meters height) and Miyan Darreh series (500 meters height) were selected. From each height, three trees and a total of 9 trees were cut and from each tree, a disk with a thickness of 10 cm and a sample with a length of 150 cm from the diameter equal to the chest upwards were prepared. After initial preparation, the samples were measured according to the standard to evaluate different properties and were evaluated and analyzed. The results showed that altitude is one of the effective factors in changing the properties of the studied properties, so that with increasing altitude, the average fiber length, fiber diameter, cavity thickness and thickness of two walls decrease and the average specific gravity and volume shrinkage, Modulus of elasticity, modulus of rupture, compreession parallel to grain, cleavage, nail withdrawal resistance in cross-section and tangential, radial and cross-sectional hardness increased. The mechanical index of Caucasian alder wood in all three elevations was in the middle range,