Technodiversity Glossary

Felled and delimbed tree lengths are pulled to the trail with a cable winch that is mounted or attached to a tractor. 

Functiogram

Advantages

• extraction over long distance without driving on the ground 
• extracting in steep terrain (uphill)
• bringing trees to a site where machines for delimbing and cross-cutting can operate
• Compared with full trees, tree-lengths offer less resistance to drag and are easier to move within the stand
  
• Compared with full trees, no nutrient removal

Limitations, threshold

• distance limited by the length of the cable, often more than 100 m
• distance limited by the weight of the cable that must be pulled by the worker, so on flat terrain not more than 50 m, downhill wider distances are possible
• cable cannot be pulled uphill, therefore no downhill extraction over longer distance 

Main use

• in stands where fully mechanized methods are not applicable due to ground conditions, tree species (large broadleaf trees, e.g.)
• with wider distance of trails, where trees must be pulled into the reach of the crane of a machine
• in combination with extraction by means of a tractor 

Economic suitability

Example:

• machine costs without personal costs: 60,00 Euro/h
• personal costs per person: 35,00 Euro/h
• number of persons: 2
• in total: 130,00 Euro/h
• regression line time per tree
  • b₀ = 4,0
  • b₁ (tree volume) = 2,0
  • b₂ (skidding distance) = 0,1

Ecological suitability

Ecograms 

Social suitability

• S-class: no contact with forest road -> S5
• E-class: simple machine work, heavy and dangerous -> E3