Influence of log and stack parameters on the conversion factors for Norway Spruce wood stacks using a 3D simulation model

Estimation of conversion factors for wood stacks in landings and their influencing parameters: a comprehensive literature review for America and Europe

“…The influence of this parameter can become stronger when the preparation of the logs is poor. Previous studies reported that the conversion factors are higher when the preparation of the logs or delimbing quality is higher (Zon 1903;Williams 1968;Kärkkäinen 1978;Pita Carpenter 1984;Briggs 1994;Diéguez Aranda et al 2003;Bäucker et al 2014b;De Miguel-Díez et al 2022b). This relationship is also supported by various roundwood measurement guidelines and several handbooks (Hamilton 1975;Purser 1999;Batista and ).…”

“…In the research conducted by Zon, different variations in the solid wood content have been reported depending on the log form (stick form): straight (13.8%), crooked (23.5%) and knotty (34.5%) (Zon 1903). Huffel (1919) reported a variation in solid wood content of 12% for log lengths ranging from 0.5 m to 1.5 m. A study conducted using a 3D simulation model reported a variation of 7.9 % the effect of this parameter in Norway Spruce (Picea abies) (De Miguel-Díez et al 2022b).…”

“…The vast majority of the references confirm that this parameter strongly influences the conversion factors. Research outcomes have shown that the solid wood content increases as the midpoint diameter of the logs increases, i.e., the conversion factors increase if the midpoint diameter does it too (von Seckendorff-Gudent 1878;Baur 1879;Zon 1903;Frothingham 1912;Huffel 1919;Schnur 1932;Schmidt 1940;Barret et al 1941;Keepers 1945;Reinhold 1951;Makkonen 1960;Williams 1968;Nikkilä et al 1974;Pita Carpenter 1984;Sairanen 1987;Zarate do Couto and Magalhães Bastos 1988;Briggs 1994;Bertola et al 2003;Diéguez Aranda et al 2003;Meza-Montoya and Simón 2005;González et al 2010;Ljubojević et al 2011;Bäucker et al 2014a,b;Foelkel 2015;Forest Service of Newfoundland and Labrador 2016;Heinzmann and Barbu 2017;Witkowska and Jodłowski 2018;Jodłowski and Witkowska 2019;De Miguel-Díez et al 2021a, 2022b. This statement is also endorsed by several roundwood measurement guidelines (Schulting 2002;Environment Although research studies have demonstrated the above relationship, there is a disparity in the current measurement guidelines used in different countries.…”

“…These variations can even be greater (Longleaf pine -Pinus palustris -18.2% and loblolly pine -Pinus taeda -20.7%) if the stacks are made up of crooked, rough and knotty logs (Williams 1968). A recently study conducted using a 3D simulation model reported a variation in solid wood content of 17.8% for Norway spruce (Picea abies) (De Miguel-Díez et al 2022b).…”

“…The effect of this parameter is so since shorter logs pack tighter (Forest Service of Newfoundland and Labrador 2016; Saskatchewan Ministry of Environment 2021). Thus, the influence of this parameter is due to the crookedness, taper, or protruding branch stubs, which results in larger voids in the stacks as the length of the logs increases; this is so since the impact of the parameters mentioned above is more significant when the log increases (Zon 1903;Pita Carpenter 1984;Sairanen 1987;Diéguez Aranda et al 2003;De Miguel-Díez et al 2022b). However, it is worth noting that the decreasing rate of the conversion factors as log lengths increase was not identical to the variation rates outlined in the found references (De Miguel-Díez et al 2022b).…”