Engler Benjamin, Prof. dr.

Accurate assessment of log and stack volumes is essential for predicting product yields and supporting decision-making in the forest industry. Despite the need to understand stack and log measurement metrics, this remains challenging due to new technological trends, complicated measurement methods, significant variation between regions, species, products, sizes, and age classifications, and prevailing misconceptions about measurement units. The main aim of this study was to compare several currently used log and timber stack volume measurement methods. Additionally, volume conversion factors from gross stack volume to net solid wood volume were calculated. To this end, Scots pine (Pinus sylvestris L.) stands were harvested using a John Deere 1170G harvester. The wood was measured using different methods and technology, including opto-electronic log measurements, manual volumetric timber stack measurements, and photo-optical stack measurements for sawmill, pallet, and other industrial partners. Conversion factors were calculated (dividing the solid wood volume under bark by the gross stacked volume over bark, including air spaces) to convert the gross stack volume into a net or solid wood volume under bark, which is an important unit for roundwood purchasing. The log measurement results showed significant differences between the various wood measurement methods across all assortments. In particular, significant differences were observed between harvester and sawmill measurements. Additionally, a comparison between manual sectional stack measurement and truck load scanning at the sawmill revealed significant differences for the medium-density fibreboard (MDF) timber assortment. Conversion factors ranged from 0.50 to 0.66, with a mean of 0.596, lower for LAS 3 m timber and higher for LAK timber. The results will contribute to a better understanding and general harmonisation of different methods for measuring stacks based on a series of studies of Scots pine assortments.

Accurate assessment of log and stack volumes is essential for predicting product yields and supporting decision-making in the forest industry. Despite the need to understand stack and log measurement metrics, this remains challenging due to new technological trends, complicated measurement methods, significant variation between regions, species, products, sizes, and age classifications, and prevailing misconceptions about measurement units. The main aim of this study was to compare several currently used log and timber stack volume measurement methods. Additionally, volume conversion factors from gross stack volume to net solid wood volume were calculated. To this end, Scots pine (Pinus sylvestris L.) stands were harvested using a John Deere 1170G harvester. The wood was measured using different methods and technology, including opto-electronic log measurements, manual volumetric timber stack measurements, and photo-optical stack measurements for sawmill, pallet, and other industrial partners. Conversion factors were calculated (dividing the solid wood volume under bark by the gross stacked volume over bark, including air spaces) to convert the gross stack volume into a net or solid wood volume under bark, which is an important unit for roundwood purchasing. The log measurement results showed significant differences between the various wood measurement methods across all assortments. In particular, significant differences were observed between harvester and sawmill measurements. Additionally, a comparison between manual sectional stack measurement and truck load scanning at the sawmill revealed significant differences for the medium-density fibreboard (MDF) timber assortment. Conversion factors ranged from 0.50 to 0.66, with a mean of 0.596, lower for LAS 3 m timber and higher for LAK timber. The results will contribute to a better understanding and general harmonisation of different methods for measuring stacks based on a series of studies of Scots pine assortments.