Hardwood Harvesting - Work Systems, Services, Costs:
A Decision Support

To the calculator

The present decision support system was developed in the context of the research project "Softwood lumber - Unused raw material potential !?", the Federal Ministry of Food, Agriculture and Consumer Protection (BMELV) (represented by the Agency for Renewable Resources (FNR), FKZ 22011209), the Lower Saxony Ministry of nutrition , Agriculture, Consumer Protection and Regional Development (ML Niedersachsen) and Volkswagen AG. The aim of the project was to determine the extent to which the high inventories of softwood trees in northern Germany (project area: Lower Saxony, Schleswig-Holstein, Saxony-Anhalt) can be used more intensively in forests such as birch, alder, poplar, willow and mountain ash. In addition to the Northwest German Forest Research Institute (NW-FVA) in Göttingen and the Department of Forest Economics and Forest Management of the Georg-August-Universität Göttingen as a project partner, the Department of Ergonomics and Process Technology of the University of Göttingen dealt in the subproject 2 "harvesting including mobilization and logistics" focus with working systems suitable for deciduous wood. As a summary, the decision support system is now available. It allows forest owners and service companies to estimate productivity and costs in hardwood harvesting with selected work systems based on fewer inputs.
In addition to the softwood tree species, the tree species beech, oak, ash, maple and cherry were added, making the decision support system versatile

Description of the work systems
For the harvest of hardwood, the following harvesting methods were selected as particularly suitable:

1. Conventional timber harvesting: motor-driven logging and back with cable tug

2. Integrated harvesting (Modified Goldberger procedure)

3. Highly mechanized timber harvesting by harvester and forwarder

4. Highly mechanized timber harvesting through hang systems (harvesters and forwarders with traction auxiliary winches)

5. Backs of motor manuel felled solid trees / solid tree sections in impassable layers (Yarding) and processing finished assortments on the forest path

6. Chipboard (harvester with Felling and collecting aggregate, back by forwarder)

Description of the decision support system
Input data required by the program to identify suitable harvesting systems are:
- main tree species (hardwood)
- BHD [cm]
- formality
- Slope [%]
- distance backstreets [m]
- Trafficability return lanes
- Volume of outgoing stock all tree species
- Total area of action [ha]
- tree height [m] (optional, input only, if known)
- Unit volume per tree (optional, input only, if known)

In addition, additional information is required for individual harvesting methods, so that productivity and costs can be determined. Additional information is required for conventional timber harvesting, integrated timber harvesting and yarding. These additional details are:

I) Conventional timber harvest
- Accessibility / Disabilities
- return distance [m]
- rope removal [m]

II) Integrated timber harvest
- volume fraction of additional assortments [%]
- Back distance [m] (corresponds to the back distance for the conventional timber harvest)

V) Yarding
- Minimum harvest per line (> 70 harvested Squaremeter)
- Rope length [m]
- Crown shape

Note on Yarding: The cost-effective productivity of the distortion forwarder (for final rumble) is set lower than expected in reality, to compensate for the low utilization of this machine.