Volume 12
Issue 4
Forestry
JOURNAL OF
POLISH
AGRICULTURAL
UNIVERSITIES
Available Online: http://www.ejpau.media.pl/volume12/issue4/abs-20.html
ENERGY EXPENDITURE IN SOME SILVICULTURAL WORKS
Witold Grzywiński
Department of Forest Utilization,
Poznań University of Life Sciences, Poland
ABSTRACT
The study presents results from studies of energy expenditure
(EE) in work associated with stand establishment and early stand treatment. The
performed experiments comprised six operations carried out on seven work stations.
The net energy expenditure was determined through measurements of pulmonary ventilation
conducted with an MWE-1 energy expenditure meter. The author determined per-minute
values of the energy expenditure for individual activities (n=14) as well as
the energy cost of an 8-h workday for each work station. The effective work time
constituted from 49.4 to 74.1% of the work shift while rest and personal breaks
amounted to 12.7–23.5%. The net unit energy expenditure ranged from 7.5 to 31.7
kJ × min-1, whereas the net energy cost of a workday ranged from 3.9
to 11.9 MJ. A majority of the five examined operations were categorized as very
heavy work – and the remaining two (motor-manual cutting of weeds and the job
of a helper during planting) with the energy expenditure below 6.3 MJ were classified
as moderate.
Key words: silviculture, work time study, energy expenditure, category of work intensity.
Witold Grzywiński
Department of Forest Utilization,
Poznań University of Life Sciences, Poland
Wojska Polskiego 71A, 60-625 Poznań
phone: +48 61 848 77 54
fax +48 61 848 77 55
email: witold.grzywinski@up.poznan.pl
Responses to this article, comments are invited and should be submitted within three months of the publication of the article. If accepted for publication, they will be published in the chapter headed 'Discussions' and hyperlinked to the article.