Contribution to research into bark properties of some species of wood

The paper presents the results of research into the density and the hardness of the bark of beech, hornbeam, oak, ash, poplar and fir. These bark properties have been investigated along the length of the log from the stump up to the diameter of 7 cm. The results show that the density of the bark is greater than the density of the wood of the same species by 6% to 41%. The hardness of the bark is smaller than the hardness of the wood by 2.3 to 6.6 times, but it is not uniform with regard to the hardness of the integral bark, the hardness of the phloem and the hardness of the rhytidome.