How much timber from Norway spruce (Picea abies L.) is left on the harvesting site as treetops? A study on scaling and grading yields of harvesters

Key message 
Timber losses during Norway spruce (Picea abies L.) harvesting with the cut-to-length method were analyzed using data from 41,948 stems. The volume of timber left on the site after CTL harvesting reached 0.111% overall and 0.454% for stems larger than 34 cm DBH, compared to official production records. On the other hand, for small stems, a surplus of 2.50% of timber was extracted compared to official records. Optimizing measurement accuracy and harvester technology is essential to improve economic efficiency.

Keywords
Forest harvesting; Volume estimation errors; Timber losses; Timber scaling; Bucking; CTL-method; Harvester technology

Publication
Dvořák, J., Štolc, M., Jankovský, M. et al. How much timber from Norway spruce (Picea abies L.) is left on the harvesting site as treetops? A study on scaling and grading yields of harvesters. Annals of Forest Science 82, 19 (2025). https://doi.org/10.1186/s13595-025-01289-4

Data availability
The datasets used and analysed during the current study are available in the Zenodo data repository (Dvořák J, Natov P, Štolc M (2025) How much timber from Norway spruce (Picea abies L.) is left on the harvesting site in the form of treetops? A study on scaling and grading yields of harvesters. V1. Zenodo. [Data set]. https://doi.org/10.5281/zenodo.14690727.

Handling editor 
Erwin Dreyer