Table 1. Description of the test site. |
Placename | | San Rossore |
Northing | | 43°41’33.08ˮN |
Easting | | 10°18’30.44ˮE |
Slope | % | 2 |
Species | | Pinus pinea L. |
Age | years | 21 |
DBH | cm | 23.1 |
Height | m | 10.7 |
Operation | | 2nd thinning |
Criteria | | Selection of candidates |
Removal | % trees | 35–40 |
Mechanization | level | Manual | Mechanized |
System | type | WT | CTL | WT | CTL |
Removal | trees ha–1 | 251a | 244a | 221a | 251a |
Removal | t ha–1 | 51a | 29.6b | 53.9a | 33.5b |
Tree size | kg tree–1 | 203a | 122b | 244a | 133b |
Wood moisture content | % | 45.8a | 47.3a | 48.2a | 43.5a |
Fig. 1. Farm tractor (a); Feller-buncher (b); Skidder (c); Harvester (d); Forwarder (e); Chipper (f).
Table 2. Technical charecteristics of the machines in the test. |
System | WT | WT | CTL | CTL | WT/CTL | WT/CTL |
Mechanization | level | Mechanized | Mechanized | Mechanized | Mechanized | Motor-manual | Both |
Machine | type | Feller-buncher | Skidder | Harvester | Forwarder | Tractor | Chipper |
Make | | John Deere | John Deere | John Deere | John Deere | Valtra | Erjo |
Model | | 759J | 460D | 870B | 1110B | 6400 | 12/90 |
Power | kW | 164 | 127 | 114 | 121 | 75 | 370/129 |
Weight | t | 27770 | 12770 | 13800 | 13670 | 4170 | 30350 |
Width | mm | 3050 | 2880 | 2510 | 2710 | 2340 | 2890 |
Length | mm | 4410 | 7345 | 5435 | 10310 | 4440 | 10400 |
Clearance | mm | 759 | 598 | 570 | 605 | 435 | 600 |
Head make | | John Deere | - | John Deere | - | - | - |
Head model | | FR21B | - | 746C | - | - | - |
Cut capacity | mm | 508 | - | 500 | - | - | - |
Table 3. Costing assumptions and machine rates. |
Unit | Chainsaw | Tractor | Feller | Skidder | Harvester | Forwarder | Chipper |
Utilization | % | 46 | 72 | 81 | 90 | 90 | 90 | 83 |
Investment | Euro | 1500 | 55 000 | 320 000 | 180 000 | 300 000 | 240 000 | 500 000 |
Resale | Euro | 450 | 16 500 | 96 000 | 54 000 | 90 000 | 72 000 | 150 000 |
Service life | years | 2 | 10 | 10 | 10 | 10 | 10 | 10 |
Utilization | SMH year–1 | 1000 | 1000 | 1600 | 1600 | 1600 | 1600 | 1600 |
Interest rate | % | 4 | 4 | 4 | 4 | 4 | 4 | 4 |
Depreciation | € year–1 | 525 | 3850 | 22 400 | 12 600 | 21 000 | 16 800 | 35 000 |
Interests | € year–1 | 50 | 1507 | 8768 | 4932 | 8220 | 6576 | 13 700 |
Insurance | € year–1 | 2500 | 2500 | 2500 | 2500 | 2500 | 2500 | 2500 |
Fuel | € year–1 | 2700 | 4500 | 47 840 | 31 408 | 27 040 | 27 040 | 72 800 |
Lubricant | € year–1 | 270 | 450 | 4784 | 3141 | 2704 | 2704 | 7280 |
Repairs | € year–1 | 263 | 1925 | 11 200 | 6300 | 10 500 | 8400 | 17 500 |
Total | € SMH–1 | 6 | 15 | 61 | 38 | 45 | 40 | 93 |
Crew | n. | 2 | 1 | 1 | 1 | 1 | 1 | 1 |
Labour | € SMH–1 | 32 | 16 | 20 | 20 | 20 | 20 | 20 |
Overheads | € SMH–1 | 8 | 6 | 16 | 12 | 13 | 12 | 23 |
Total rate | € SMH–1 | 46 | 37 | 97 | 70 | 78 | 72 | 136 |
Table 4. Productivity by treatment and work phase. |
Mechanization | Manual | Mechanized |
System | type | WT | CTL | WT | CTL |
Felling | odt SMH–1 | 0.9a | 0.6b | 18.2c | 4.9d |
Extraction | odt SMH–1 | 2.3a | 0.6b | 13.5c | 6.9d |
Chipping | odt SMH–1 | 18.7a | 16.7a | 15.5a | 17.5a |
Extraction distance | m | 233a | 140a | 189a | 174a |
Load size | odt | 0.410a | 0.212b | 0.958c | 3.845d |
Fig. 2. Specific fuel consumption per unit product by treatment and work phase. Notes: Different letters over different bars indicate that the difference between the mean fuel consumption values are statistically significant at the 5% level according to Scheffe’s multiple comparison test; WT = motor-manual whole-tree harvesting; CTL = motor-manual cut-to-length harvesting; Mech. WT = mechanized whole-tree harvesting; Mech CTL = mechanized cut-to-length harvesting; Felling also includes delimbing and crosscutting in the case of CTL harvesting operations.
![3](/img/article1003/3.jpg)
Fig. 3. Thinning cost by treatment and work phase. Notes: Different letters over different bars indicate that the difference between the mean total cost values are statistically significant at the 5% level according to Scheffe’s multiple comparison test; WT = motor-manual whole-tree harvesting; CTL = motor-manual cut-to-length harvesting; Mech. WT = mechanized whole-tree harvesting; Mech CTL = mechanized cut-to-length harvesting; Felling also includes delimbing and crosscutting in the case of CTL harvesting operations.
Table 5. Anova table for the effect of mechanization level and harvesting system on unit cost and fuel consumption. |
Thinning cost (€ odt–1) |
Effect | DF | SS | η2 | F-Value | P-Value |
Mechanization | 1 | 20003 | 0.71 | 113.034 | <0.0001 |
System | 1 | 4863 | 0.17 | 27.479 | 0.0008 |
Interaction | 1 | 1861 | 0.07 | 10.515 | 0.0118 |
Residual | 8 | 1416 | 0.05 | | |
Specific fuel consumption (L odt–1) |
Effect | DF | SS | η2 | F-Value | P-Value |
Mechanization | 1 | 17.452 | 0.22 | 13.529 | 0.0062 |
System | 1 | 40.853 | 0.52 | 31.668 | 0.0005 |
Interaction | 1 | 10.155 | 0.13 | 7.872 | 0.0230 |
Residual | 8 | 10.32 | 0.13 | | |
Table 6. Site impact for the four treatments on test. |
Mechanization | Manual | Mechanized |
System | type | WT | CTL | WT | CTL |
Wounding | % trees | 6.0a | 15.7 | 2.5ab | 1.5b |
Wound size | cm2 | 433a | 407a | 106a | 431a |
Soil density untrafficked | g cm–3 | 1.30a | 1.18a | 1.25a | 1.21a |
Soil density trafficked | g cm–3 | 1.28a | 1.28a | 1.28a | 1.36a |
Difference | % | –1.2 | 8.8 | 2.5 | 11.9 |
t test | p-value | 0.3462 | <0.0001 | 0.2332 | <0.0001 |