Even though the process of civilization has made man independent of nature and raised him to a higher level, yet he is continually aware of the fundamental influence of nature on generations of mankind.

The aspen is a forest tree, occurring widely throughout the whole of Europe, and extending beyond the Arctic Circle in the north. In central Europe it grows in lowland and on mountains up to and above 1000 metres; it is most plentiful, however, in hill country, coppice forests and forests which are clear-felled.

The principal raw material yielded by trees is wood, which can he used in many ways and for many purposes and which, along with coal – the product of trees of earlier geological periods – made possible the smelting of ores and the development of all branches of industry.