scholarly journals Estimation of Over- and Under-Bark Volume of Scots Pine Timber Produced by Harvesters

Forests ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 626
Author(s):  
Monika Sedmíková ◽  
Radim Löwe ◽  
Martin Jankovský ◽  
Pavel Natov ◽  
Rostislav Linda ◽  
...  

Harvesters produce one third of timber in Czechia. The aim of this study was to analyze the over- and under-bark volume estimates of Scots pine (Pinus sylvestris L.) timber produced by a mid-performance harvester. The data were collected between March 2017 and June 2018. In total, 4661 stems cut into 29,834 logs were analyzed. For volume estimation, StanForD offers several price categories using various algorithms. Three of these price categories are relevant for Czech forestry—M3s, M3toDE, and M3miDE. The M3s price category is based on the estimation of partial volumes of 10 cm long sections, which are summed. Therefore, this price category represents the volume estimation closest to the true volume. By comparison, the M3toDE and M3miDE price categories use the same algorithm for volume estimation, which is based on the Huber formula using a midspan diameter rounded down to the nearest whole centimeter. The M3toDE price category underestimated the over-bark volume by 6.48% compared to the reference price category M3s. The mean log volume estimated through the M3s price category was significantly higher than the M3toDE volume both in individual grades and without grading. We found significant differences between under-bark volume estimates by the diameter band bark deduction method (DBM) and the parametric linear bark deduction method (PLM) used in harvester’s systems according to the Guidelines for Electronic Scaling of Timber for Harvesters in Czechia (GEH) for Scots pine butt logs with rough bark, and also for other logs with normal bark thickness. To obtain under-bark volume estimates of Scots pine timber that are comparable with the Guidelines for Timber Scaling in Czechia (GTS) using the parametric nonlinear bark deduction method (PNM), we recommend using the algorithm of the M3toDE price category, with double bark thickness determined by the diameter band bark deduction method.

Author(s):  
Ferréol Berendt ◽  
Erik Pegel ◽  
Lubomir Blasko ◽  
Tobias Cremer

AbstractBark characteristics are not only used in the forest-wood supply chain, for example to calculate standing volumes, but also to transform wood volumes and masses. In this study, bark thickness, bark volume and bark mass were analyzed on the basis of 150 Scots pine discs, with a mean diameter of 13 cm. The mean double bark thickness was 3.02 mm, the mean bark volume proportion was 5.6% and mean bark mass proportion was 3.3%. Bark proportions were significantly affected by the log-specific variables ‘diameter over bark’, ‘proportion of bark damage’ and ‘double bark thickness’.


2002 ◽  
Vol 32 (8) ◽  
pp. 1434-1440
Author(s):  
Heikki Nuorteva

The responses of Scots pine (Pinus sylvestris L.) foliar boron (B) concentrations to artificial defoliation by green pruning were studied by examining sample trees for 3 years after the treatments. In winter, concentrations of boron in foliage were determined individually from needles on the lateral top shoots of 168 sample trees (at the beginning 2–8 m, at the end 4–10 m tall). To prevent the pruning residues from affecting the nutrition of the sample trees, all pruned branches were transported away from the research area. Before pruning, there were no differences in foliar B among the pruning classes. Reduction of the living crown by pruning (LCRP, % of the initial crown ratio) 50% or more increased the concentrations of foliar B drastically for 3 years. The increase was greatest in the largest trees with the highest LCRP (about 70%), where the mean concentrations of foliar B one year after pruning were nearly 180% higher than in the unpruned trees. Pruning of the dead branch whorls or only the few lowest living whorls did not affect the boron nutrition of the trees. In the current study, the ability of rapid and sufficiently large defoliation to increase B concentrations for several years in the Scots pine foliage was confirmed experimentally; earlier suggestions have been based on analyses made after defoliation. The potential suitability of green pruning is discussed as a method for improving the boron status of trees in boron-deficient areas.


2020 ◽  
Vol 50 (1) ◽  
pp. 42-50
Author(s):  
Grzegorz Szewczyk ◽  
Robert Jankowiak ◽  
Bartosz Mitka ◽  
Piotr Bożek ◽  
Piotr Bilański ◽  
...  

Blue stain is a type of discoloration that considerably lowers the aesthetic qualities of wood. During harvesting, fungal inoculum finds its way into the wood through places of cutting, delimbing, and damage to the tree stem. The development of peripheral blue stain in the logs of Scots pine (Pinus sylvestris L.) due to damage by a harvester head was investigated, using logs felled and delimbed with a chainsaw as reference. The development of blue stain was related to the age class of the stand, the date of felling, and the microclimatic conditions of the wood storage place. The mean surface area of blue stain in logs produced with the harvester was almost 35 cm2, approximately 30% larger than that of the reference logs. In stands of the fourth age class (diameter at breast height 32 cm), the surface of blue stain was more than two times larger than that of stands of the third age class (diameter at breast height 24 cm). The mean area of blue stain in wood stored after spring felling (19.3 cm2) was about 50% of that after summer felling (38.2 cm2). In particular, the development of blue stain in logs obtained with a harvester was visible between weeks 6 and 9 after spring felling and between weeks 3 and 6 after summer felling. For both felling dates, the range of blue stain depended less on air temperature around the wood stack and depended more on the duration of storage.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ferréol Berendt ◽  
Felipe de Miguel-Diez ◽  
Evelyn Wallor ◽  
Lubomir Blasko ◽  
Tobias Cremer

AbstractWithin the wood supply chain, the measurement of roundwood plays a key role due to its high economic impact. While wood industry mainly processes the solid wood, the bark mostly remains as an industrial by-product. In Central Europe, it is common that the wood is sold over bark but that the price is calculated on a timber volume under bark. However, logs are often measured as stacks and, thus, the volume includes not only the solid wood content but also the bark portion. Mostly, the deduction factors used to estimate the solid wood content are based on bark thickness. The aim of this study was to compare the estimation of bark volume from scaling formulae with the real bark volume, obtained by xylometric technique. Moreover, the measurements were performed using logs under practice conditions and using discs under laboratory conditions. The mean bark volume was 6.9 dm3 and 26.4 cm3 for the Norway spruce logs and the Scots pine discs respectively. Whereas the results showed good performances regarding the root mean square error, the coefficient of determination (R2) and the mean absolute error for the volume estimation of the total volume of discs and logs (over bark), the performances were much lower for the bark volume estimations only.


Author(s):  
Bartłomiej Woś ◽  
Piotr Gruba ◽  
Jarosław Socha ◽  
Marcin Pietrzykowski

This work evaluates current mercury (Hg) contamination in Poland, represented by the Hg concentrations in Scots pine foliage. Samples were collected over 295 investigation plots in monitoring grids throughout Poland, from pines aged between 12 and 147 years. Analyses were conducted with consideration of bioclimatic factors and soil properties. Concentrations in the pine foliage did not exceed the values characteristic of an ecosystem unaffected by industrial pollution, ranging from 0.0032 to 0.0252 mg kg−1 dry mass. However, pine stands located in western and central Poland, and in the northwest near the Baltic Sea, exhibited higher Hg concentrations in foliage than in eastern regions. Hg content in foliage depends on the mean temperature of the driest quarter, as well as on Hg content in soils. This indicates that the periods of drought observed in recent years in Poland may affect Hg concentrations in pine foliage.


Biologia ◽  
2007 ◽  
Vol 62 (6) ◽  
Author(s):  
Behiye Bilgen ◽  
Nuray Kaya

AbstractGenetic variation in six natural populations of Scots pine (Pinus sylvestris L.) was determined with isoenzyme analyses. For this purpose, haploid female gametophytes of seeds and horizontal starch gel electrophoresis technique were used. A total of 17 loci and 58 alleles were observed in studying 10 enzyme systems. The average proportion of polymorphic loci for populations ranged from 58.8% to 70.6%. The average number of alleles per locus per population was 2.65. The mean estimated expected heterozygosity (He) of populations was 0.294. A rather high proportion of genetic diversity (96.4%) was due to within-population variation and the remaining (3.6%) was due to variation among populations. The level of gene flow (Nem) was found to be 6.69 per generation. Nei’s genetic distance coefficient ranged from 0.006 to 0.027 (mean 0.017) among all possible population pairs. The mean value of Nei’s genetic distance is similar to the values reported for other European Scots pine populations. The low mean value of Nei’s genetic distance among populations is enough to explain low interpopulation variation. According to genetic variation parameters, three out of six populations (Akdagmadeni-Yozgat, Refahiye-Erzincan and Vezirkopru-Samsun) appear to be preferable populations for genetic conservation and forest tree breeding programs.


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