Fig. 1. Research venue.

Table 1. Tree stand and marked tree characteristics.
Tree stand characteristics Marked tree characteristics
Characteristic Stand 1 Stand 2 Characteristic Plot 1 Plot 2
Compartment area (ha) 20.6 14.4 Cutting area (ha) 20.6 12.4
Stand age (years) 130 160 Total volume (m3) 1145 2376
Breast height diameter (dbh) (cm) 46 58 No. of trees 475 1063
Average height (m) 26 29 Average tree volume (m3 tree–1) 2.41 2.24
Yield class III III Dbh (cm) 52 56
Stand density (trees ha–1) 302 164 Average height (m) 29.5 29
Stand crown density (%) 70 40 Natural pruning (%) 60 60
Natural pruning (%) 60 60 Distance between marked trees (m) 20.8 10.8
Distance between trees (m) 5.8 7.8 - - -
Felling type Open seeding felling Intermediate felling - - -

Fig. 2. Work time structure (adapted by Björheden and Thompson 2000).

Table 2. Felling operation structure.
Stage Symbol Start End
Moving to the felled tree depl when the feller starts moving toward the tree to be cut when the feller reaches the tree
Preparing the workplace plm when the feller starts clearing around the tree when the feller ends the preparation of the workplace
Choosing the felling direction and preparing the escape route add when the feller starts judging where the tree will fall when the feller prepared the escape route
Sink cutting et when the feller starts cutting the sink when the feller extracted the sink
Back-cutting etpot when the feller starts cutting in the opposite direction when the tree starts to fall
Fellers’ retreat, tree hitting the ground and fellers’ return rm when the tree starts to fall and the feller retreats on the escape route when the tree hits the ground and the feller returns near the stump
Wood fibre cutting off the stump nc when the feller starts to cut off the stump the wood fibre split from hinge wood when the feller finished cutting the wood fibre off the stump
Wood fibre cutting off the stem tct when the feller starts to cut off the stem the wood fibre split from hinge wood when the feller finished cutting the wood fibre off the stem
Stump debarking cc when the assistant starts the stump debarking with an axe when the assistant finished the stump debarking
Table 3. Work time structure according to stages and activities.
Work time structure Operations Stages Activities
TT NW Felling - Moving to and from the workplace at the beginning and ending of the schedule
WP NT Felling - Meal, rest, needs, moving from one group of trees to another, organization
WT PW MW Felling et
etpot		 Sink cutting and extraction
Back cutting and wedging
CW Felling plm
add
rm		 Removing obstacles from around the tree and butt trimming
Analysing factors involved in choosing the felling direction and establishing the felling direction
Fellers’ retreat, tree hitting the ground and fellers’ return
SW PT RT Felling depl Moving from one tree to the next
ST MT Felling - Saw chain sharpening and chain tension
Saw chain replacement and guide bar turning
Cleaning the air filter
RF Felling - Chainsaw fuelling with mixed fuel and oil for chain lubrication
AW Felling nc
tct
cc		 Wood fibre cutting off the stump and stem
Stump debarking with an axe
Work time structure: TT – total time; NW – non-workplace time; WP – workplace time; NT – non-work time; WT – work time; PW – productive work time; SW – supportive work time; MW – main work time; CW – complementary work time; PT – preparatory time; ST – service time; AW – ancillary work time; RT – relocation time; PL – planning time; MT – maintenance time; RF – refuel time.
Table 4. Minimum number of measurements.
Operation Venue Size of sample lot Parameter values (%) Number of measurements
p q calculated made
Felling Felling area 50 52 48 96 491
p – the percentage of unproductive time; q – the percentage of active time.
Table 5. Worktime structure in felling operations.
Plots No. of trees Volume Workplace time (WP) Non-workplace time (NW) Total time (TT)
Productive work time (PW) Supportive work time (SW) Non-work time (NT)
m3 s m–3 % s m–3 % s m–3 % s m–3 % s m–3 %
S1 241 537.528 69.55 19.59 120.30 33.88 124.78 35.14 40.48 11.39 355.11 100
s tree–1 s tree–1 s tree–1 s tree–1 s tree–1
155.12 268.32 278.31 90.29 792.03
S2 250 655.981 55.92 17.66 97.25 30.73 111.98 35.38 51.35 16.23 316.50 100
s tree–1 s tree–1 s tree–1 s tree–1 s tree–1
146.72 255.19 293.82 134.75 830.48
WP – workplace time; PW – productive work time; SW – supportive work time; NT – non-work time; NW – non-workplace time; TT – total time.

Fig. 3. Felling productivity for different tree diameters at the breast height (dbh) (without delay). View larger in new window/tab.

Fig. 4. Work time structure in tree felling: MW – main work time; CW – complementary work time; PT – preparatory time; AW – ancillary work time; ST – service time; NT – non-work time; NW – non-workplace time.

Fig. 5. Time consumption in tree felling: Tdepl – work time corresponding to depl stage; Tplm – work time corresponding to plm stage; Tadd – work time corresponding to add stage; Tet – work time corresponding to et stage; Tetpot – work time corresponding to etpot stage; Trm – work time corresponding to rm stage; Tnc – work time corresponding to nc stage; Ttct – work time corresponding to tct stage; Tcc – work time corresponding to cc stage.

Table 6. Statistical indicators of work time variation corresponding to stages in the felling of one m3 of wood and to operational variables measured in felling areas.
Descriptive statistics Mean Median Standard Error Standard Deviation Variation Coefficient (%)
plot 1 plot 2 plot 1 plot 2 plot 1 plot 2 plot 1 plot 2 plot 1 plot 2
Descriptive statistics of work time (s m–3) according to each stage of felling
Tdepl 19.94 17.66 19.72 15.51 1.11 1.80 5.85 10.35 29.33 58.62
Tplm 7.16 6.83 7.39 3.40 1.02 1.27 5.39 7.30 75.27 106.9
Tadd 7.39 6.55 7.02 5.95 0.45 0.75 2.36 4.32 32.92 66.01
Tet 33.16 29.95 33.41 27.36 1.14 2.01 6.06 11.55 18.26 38.56
Tetpot 19.15 16.76 18.91 14.71 0.64 0.95 3.41 5.44 17.81 32.44
Trm 4.11 4.11 4.10 3.92 0.19 0.41 0.99 2.33 24.16 56.65
Tnc 4.86 4.57 4.62 4.31 0.26 0.36 1.38 2.08 28.34 45.55
Ttct 14.46 13.36 13.67 13.55 0.77 1.26 4.09 7.26 28.29 54.33
Tcc 64.55 58.84 61.16 58.55 2.28 4.00 12.06 22.98 18.68 39.06
Teff 174.78 158.63 174.76 163.08 6.31 11.06 33.37 63.53 19.09 40.05
Descriptive statistics of dbh, sd (cm), d (m) and V (m3)
dbh 44.6 43.6 44.0 44.0 0.66 0.67 10.18 10.56 22.80 24.20
sd 53.7 52.7 54.5 53.0 0.82 0.82 12.68 12.95 23.63 24.56
d 20.9 10.5 16.0 8.0 1.12 0.59 17.31 9.32 8.29 8.87
V 2.230 2.624 2.005 2.313 0.07 0.10 1.048 1.57 46.99 9.78
Tdepl – work time corresponding to depl stage; Tplm – work time corresponding to plm stage; Tadd – work time corresponding to add stage; Tet – work time corresponding to et stage; Tetpot – work time corresponding to etpot stage; Trm – work time corresponding to rm stage; Tnc – work time corresponding to nc stage; Ttct – work time corresponding to tct stage; Tcc – work time corresponding to cc stage; Teff – actual work time corresponding to a complete succession of stages in tree felling; d – distance between harvested trees; sd – stump diameter; V – tree volume.
Table 7. Simple linear regression analysis of Tdepl in relation to d.
ANOVA Significance of variable coefficient
R2 Standard Error Degrees of freedom F Variable Coefficient Standard Error t Statistic P-value
Simple linear regression analysis of Tdepl in relation to d
Plot 1
0.77 15.629 Regression 1 Residual 239 779.313*** Constant 9.362 1.579 5.930 < 0.001***
d 1.630 0.058 27.916 < 0.001***
Plot 2
0.78 14.663 Regression 1 Residual 248 894.867*** Constant 7.527 1.401 5.372 < 0.001***
d 2.970 0.099 29.914 < 0.001***
Asterisks denote F significance and significant correlations, *** P-value < 0.001; Tdepl – work time corresponding to depl stage; d – distance between harvested trees.
Table 8. Simple linear regression analysis of Tet and Tetpot in relation to sd and dbh.
ANOVA Significance of variable coefficient
R2 Standard Error Degrees of freedom F Variable Coefficient Standard Error t Statistic P-value
Simple linear regression analysis of Tet in relation to sd
Plot 1
0.49 26.665 Regression 1 Residual 239 234.216*** Constant –38.433 7.476 –5.141 < 0.001***
sd 2.072 0.135 15.304 < 0.001***
Plot 2
0.42 28.964 Regression 1 Residual 248 182.171*** Constant –31.017 7.705 –4.026 < 0.001***
sd 1.917 0.142 13.497 < 0.001***
Simple linear regression analysis of Tet in relation to dbh
Plot 1
0.47 27.349 Regression 1 Residual 239 210.854*** Constant –39.666 7.951 –4.989 < 0.001***
dbh 2.520 0.174 14.521 < 0.001***
Plot 2
0.40 29.614 Regression 1 Residual 248 163.506*** Constant –29.343 7.991 –3.672 < 0.001***
dbh 2.277 0.178 12.787 < 0.001***
Simple linear regression analysis of Tetpot in relation to sd
Plot 1
0.47 15.112 Regression 1 Residual 239 206.574*** Constant –17.184 4.237 –4.056 < 0.001***
sd 1.103 0.077 14.373 < 0.001***
Plot 2
0.38 16.543 Regression 1 Residual 248 151.244*** Constant –12.618 4.401 –2.867 < 0.001***
sd 0.998 0.081 12.298 < 0.001***
Simple linear regression analysis of Tetpot in relation to dbh
Plot 1
0.43 15.625 Regression 1 Residual 239 177.786*** Constant –16.982 4.542 –3.739 < 0.001***
dbh 1.322 0.099 13.334 < 0.001***
Plot 2
0.35 16.912 Regression 1 Residual 248 134.008*** Constant –11.408 4.564 –2.500 < 0.001***
dbh 1.177 0.102 11.576 < 0.001***
Asterisks denote F significance and significant correlations, *** P-value < 0.001; Tet – work time corresponding to et stage; Tetpot – work time corresponding to etpot stage; sd – stump diameter; dbh – breast height diameter.
Table 9. Simple linear regression analysis of Tnc in relation to sd and dbh.
ANOVA Significance of variable coefficient
R2 Standard Error Degrees of freedom F Variable Coefficient Standard Error t Statistic P-value
Simple linear regression analysis of Tnc in relation to sd
Plot 1
0.24 5.593 Regression 1 Residual 239 74.898*** Constant –4.870 1.849 –2.634 0.009**
sd 0.290 0.033 8.654 < 0.001***
Plot 2
0.21 6.503 Regression 1 Residual 248 65.385*** Constant –3.180 1.730 –1.838 0.067
sd 0.258 0.032 8.086 < 0.001***
Simple linear regression analysis of Tnc in relation to dbh
Plot 1
0.18 6.821 Regression 1 Residual 239 54.356*** Constant –3.555 1.983 –1.793 0.074
dbh 0.319 0.043 7.373 < 0.001***
Plot 2
0.16 6.712 Regression 1 Residual 248 46.223*** Constant –1.563 1.811 –0.863 0.388
dbh 0.274 0.040 6.799 < 0.001***
Asterisks denote F significance and significant correlations, *** P-value < 0.001; Tnc – work time corresponding to nc stage; sd – stump diameter; dbh – breast height diameter.
Table 10. Simple linear regression analysis of Tcc in relation to sd and dbh.
ANOVA Significance of variable coefficient
R2 Standard Error Degrees of freedom F Variable Coefficient Standard Error t Statistic P-value
Simple linear regression analysis of Tcc in relation to sd
Plot 1
0.50 35.323 Regression 1 Residual 239 237.089*** Constant –14.057 10.269 –1.369 < 0.001***
sd 3.452 0.224 15.398 < 0.001***
Plot 2
0.44 38.100 Regression 1 Residual 248 197.969*** Constant –8.728 10.282 –0.849 < 0.001***
sd 3.223 0.229 14.070 < 0.001***
Simple linear regression analysis of Tcc in relation to dbh
Plot 1
0.47 36.399 Regression 1 Residual 239 209.360*** Constant –3.572 10.205 –0.350 < 0.001***
dbh 2.674 0.185 14.469 < 0.001***
Plot 2
0.43 38.529 Regression 1 Residual 248 188.092*** Constant –4.634 10.250 –0.452 < 0.001***
dbh 2.591 0.189 13.715 < 0.001***
Asterisks denote F significance and significant correlations, *** P-value < 0.001; Tcc – work time corresponding to cc stage; sd – stump diameter; dbh – breast height diameter.
Table 11. Multiple linear regression analysis of Teff in relation to sd and d.
ANOVA Significance of variable coefficient
R2 Standard Error Degrees of freedom F Variable Coefficient Standard Error t Statistic P-value
Simple linear regression analysis of Teff in relation to sd and d
Plot 1
0.65 86.320 Regression 1 Residual 239 218.149*** Constant –77.353 24.486 –3.159 0.002**
sd 7.146 0.442 16.169 < 0.001***
d 3.590 0.325 11.043 < 0.001***
Plot 2
0.58 97.215 Regression 1 Residual 248 170.368*** Constant –48.664 26.036 –1.869 0.062
sd 6.258 0.483 12.959 < 0.001***
d 7.277 0.667 10.917 < 0.001***
Asterisks denote F significance and significant correlations, *** P-value < 0.001; Teff – actual work time corresponding to a complete succession of stages in tree felling; d – distance between harvested trees; sd – stump diameter.