Physical exertion and working efficiency of reforestation workers

Heart rate (HR) was monitored on 34 tree planters while they worked. HR data was collected for a complete working day on 19 subjects and for shorter periods of time on 15 subjects. Video of work tasks was recorded on 22 subjects (video was recorded on 7 of the subjects for whom HR was monitored through a full working day) and analyzed for working pace and proportion of time spent on each task.HR during a full day (9.0 ± 1.2 hours) of tree planting work was 115.2 ± 8.8 beats.min-1, and working HR was 128.2 ± 15.6 beats.min-1 for 82.5 ± 6.8% of the work day. Mean work pace was 452 ± 174 trees.h-1, and the proportion of time spent planting each tree was 53 ± 8% of the working time. Significant (P < 0.05) positive correlations were found between work pace and experience level, and between work pace and working HR, and a significant (P < 0.05) negative correlation was found between experience level and HR for a given work pace. No significant relationships were found between experience level or work pace and the proportion of time spent planting each tree.Tree planters work at approximately 65% of age-predicted HRmax, and maintain HR at approximately 59% of HRmax throughout the entire working day. Productivity in these workers appears to be related to effort rather than to experience or task efficiency per se.Harvesting of Canada's forests, which cover almost 250 million hectares of land and account for 27% of the country's land mass [1], is an important industry and vital part of the Canadian economy, worth approximately $6 billion per annum [2]. In the province of British Columbia in the 2008/09 fiscal year, manual tree planters reforested approximately 230 million tree seedlings over an area of 180,000 hectares [3]. Tree planting is typically piece work (work paid according to unit production - in this case on a per tree seedling basis) involving heavy lifting and walking over significant distances each day, and remote worksites with relatively primitive living condit