The introduction of chain saws and tractors in the early 1950's marked
the beginning of a change in tree harvesting techniques from the old
manual methods to mechanized operations. It was followed by a rapid
evolution both technically and systematically. Hence, the requirements
for improved know- ledge of operational efficiency also increased.
Changing relations between Man, machines and environment brought about
new experiences and awareness of a physiological and ergonomic nature.
Improved knowledge of both machine technology and planning of work on a
small or large scale has grown increa- singly important for an efficient
utilization of expensive machines and other equipment. The need for a
textbook on tree harvesting techniques including expe- riences made in
recent years is enhanced. The book presented here is prima- rily based
on lectures given on the subject of Forest Techniques at the Faculty of
Forestry at the Swedish University of Agricultural Sciences and after
modifications also at the University of Nairobi (Kenya). Thus, the book
is written primarily for students at the faculties and institutes of
forestry. However, it is also useful for persons actively occupied in
forest operations. The presentation of this book in its original Swedish
version in 1972 created a considerable interest in the preparation of a
condensed edition in English. Thus interest has been expressed in
Finland, Norway, Holland, Canada, U.S.A., Brazil, Japan, Poland,
Scotland and Yugoslavia.