Juvenile-mature wood evaluation along the bole considering the influence of silvicultural treatments

Abstract

Wood used for structural purposes has increased in the last decade in Spain. However, as raw material, wood needs to comply with requirements that are not always present. Knowledge about the wood quality from the trees on the stand is essential for providing feedback to forest managers and for taking the required actions to obtain suitable silviculture treatments. Two of the main wood species used in construction in Spain, Pinus nigra and Pinus sylvestris, have been studied in order to determine the amount of juvenile wood, which has been identified as a harmful characteristic for its decrease in quality of the physical-mechanical properties of these species. Being relevant for the best quality of timber in the part along the bole where the logs are obtained, the distribution of juvenile wood at different heights and the effect of several silvicultural treatments have had on juvenile wood formation has been considered. The juvenile-mature wood boundary (transition year) was calculated through segmented linear mixed models employing as variables annual latewood density, obtained through micro X-ray densitometry, silvicultural practices, and a drought index. The results show how juvenile and mature wood is distributed along the bole and the proportion of juvenile wood. Its reduction according to the different thinning and pruning silvicultural practices is presented.

Efficient use of timber resources in Mexico: Historical development and current challenges

“…As described by Román et al (2014), individuals with dimensions similar to those shown, have the potential to produce poles, firewood and rural constructions. Furthermore, juvenile wood is associated with shrinkage and a high probability of warping and cracking in the final products (Ruano and Hermoso, 2021;Ruano et al, 2022). Therefore, they are not regularly integrated into traditional industrial processes.…”

“…Firstly, with regeneration felling, a large volume of biomass from large individuals is planned to be removed; secondly, regeneration release logging plans to remove all adult individuals. High-quality raw material is obtained from these treatments, since intensive silviculture promotes self-pruning and the development of straight stems in the stock (Ruano and Hermoso, 2021). Priority should be given to the plywood industry due to the high quality of the raw material, followed by the sawmill industry for thick and thin diameters.…”

Intrinsic Regulation of Diameter Growth in Woody Plants

“…"Juvenile wood" has been extensively investigated, and some investigators have considered juvenile wood and corewood to be synonymous terms (e.g., [16]). On the other hand, the transition from juvenile to mature wood during secondary growth has frequently been described as a gradual, rather than well delineated, change in various wood properties, making a transition point difficult to identify clearly [16,[18][19][20]. In contrast, corewood terminates abruptly at a latewood-earlywood boundary and physically is clearly delineated from the surrounding outerwood, particularly after wood has dried.…”

Mitigating Off-Gassing and Self-Heating in Fuel Wood Pellets Storage: A Raw Materials Selection and Pre-Treatment Centred Approach

“…As a result, a tree stem has a consistent core diameter of juvenile wood throughout its length. The proportion of juvenile wood in a tree increases with increasing tree height [72]. Therefore, when trees are felled and bucked, pulpwood, top sawlogs, and thinnings tend to have a much higher content of juvenile wood than butt sawlogs.…”

“…sawmill that handles small diameter top sawlogs with a bottom diameter less than 21.9 cm under bark. Mora sawdust contains a high proportion of mature wood, while Blyberg sawdust has a high proportion of juvenile wood due to the variations in positions and diameters of sawlogs from which the sawdust is generated [72]. A total of about 2000 tonnes of fresh sawdust was delivered to two pellet factories and processed into wood pellets within a month of delivery.…”