Comparison of chemical composition of bark of fast-growing poplar with bark of other deciduous tree species

The aim of the study was to compare the content of some chemical substances in a bark of about 3-year-old fast-growing poplars Populus deltoides x maximowiczii and Populus trichocarpa with literature data on the chemical composition of a bark of older deciduous trees. The Populus deltoides x maximowiczii and Populus trichocarpa material were obtained from the Wolica experimental field belonging to the Institute of Biology, Department of Genetics, Plant Breeding and Biotechnology at Warsaw University of Life Sciences. Using the standard laboratory procedures, the chemical composition of the bark was examined, i.e. the content of extractives and mineral substances, cellulose, lignin and the content of soluble substances in 1% NaOH. The cellulose content in the bark of the 3-year-old poplars tested was higher by from 10 to 23% in relation to its content in the bark of older trees. Whereas, the content of lignin in the bark of the 3-year-old poplars was lower by from 10 to 20% compared to its content in the bark of other older trees. It was found that based on the data obtained, it is difficult to clearly determine which of the generally accepted factors affect the content of mineral substances and substances soluble in 1% NaOH in the bark. However, the content of extractives soluble in a mixture of ethanol and benzene (1:1) w/w, chloroform and ethanol (93:7) w/w as well as cellulose and lignin in the bark depends on the species, age, habitat conditions of the trees and the height of the trunk from which the samples were collected.