scholarly journals Effects of genetic entry and spacing on growth and wood properties in Scots pine

2010 ◽  
Vol 2010 (110) ◽  
Author(s):  
Jaume Gort-Oromi
Author(s):  
А.В. Лебедев ◽  
В.В. Кузьмичев

Сосна обыкновенная является одной из основных лесообразующих пород Европы, а ее древесина находит широкое применение в лесопромышленном комплексе. При оценке углерододепонирующих функций считается, что конверсионные коэффициенты являются константными по времени. Последние исследования показывают, что происходящие климатические изменения оказывают существенное влияние на прирост древесины и ее свойства. Цель данного исследования – выявление долговременных тенденций в изменении биомассы фракций деревьев сосны обыкновенной в Европе, происходящих с 1940 г. Для проверки гипотезы о влиянии календарного года на биомассу фракций деревьев проводился регрессионный анализ с применением линейных моделей смешанных эффектов. Проведенный статистический анализ позволил выявить достоверное влияние (при p < 0,05) календарного года только на биомассу стволов в коре. Наиболее сильно изменения проявляются для деревьев в молодняках и средневозрастных насаждениях, где происходит формирование наибольшего радиального прироста. Для крупномерных стволов, согласно результатам моделирования, снижение биомассы стволов в коре не прослеживается. В ближайшие десятилетия в результате продолжающихся климатических изменений процесс снижения биомассы и плотности древесины крупномерных стволов должен усилиться. Выявленные изменения биомассы сопровождаются снижением плотности древесины, что происходит в результате увеличения в структуре годичного прироста более рыхлой и менее плотной ранней древесины. Таким образом, в условиях ускоряющихся темпов роста древесных растений объемы стволов и запасы древесины не должны напрямую пересчитываться в депонированный углерод с учетом исторических значений конверсионных коэффициентов. Это также следует учитывать при мониторинге, моделировании и использовании углерода и биомассы в лесах в условиях глобальных изменений. Scots pine is one of the main forest-forming species in Europe, and its wood is widely used in the timber industry. When evaluating carbon-depositing functions, the conversion rations are assumed to be constant over time. Recent studies show that the ongoing climatic changes have a significant impact on the growth of trees and wood properties. Therefore, the purpose of this study is to identify long-term trends in the change in the biomass of Scots pine tree fractions in Europe since 1940. To test the hypothesis about the influence of the calendar year on the biomass of tree fractions, regression analysis was performed using linear mixed-effect models. The performed statistically analysis made it possible to reveal a significant effect (p < 0.05) of the calendar year only on the biomass of the trunks in the bark. The changes are most pronounced for trees in young and middle-aged stands, where the formation of the greatest radial growth occurs. For large-sized trunks, according to the simulation results, the biomass of the stems in the bark is not traced. In the coming decades, as a result of ongoing climate change, the decline in biomass and wood density of largesized stems should intensify. The revealed changes in biomass are accompanied by a decrease in wood density, which occurs as a result of an increase in the structure of the annual growth of looser and less dense early wood. Thus, in the context of accelerating growth rates of woody plants, the volume of trunks and wood stock should not be directly converted into deposited carbon, considering the historical values of conversion rations. This should also be considered when monitoring, modeling and using carbon and biomass in forests in the face of global change.


Holzforschung ◽  
2012 ◽  
Vol 66 (2) ◽  
Author(s):  
Sheikh Ali Ahmed ◽  
Margot Sehlstedt-Persson ◽  
Olov Karlsson ◽  
Tom Morén

Abstract Scots pine (Pinus sylvestris L.) sapwood lumber was collected after kiln drying and preservative treatment with Celcure AC 800 (a copper-amine wood preservative). Distribution of the preservative throughout the lumber was visually examined. Not all, but some samples showed specific localized areas without any preservative distribution throughout their entire length. Those samples were assessed further for anatomical properties, specifically in impregnated and unimpregnated areas. Additional study was conducted on the morphological nature and redistribution of lipophilic extractives using three different histochemical staining methods. Intrinsic wood properties – especially the frequency of axial resin canals and the percentage of canals blocked – were found to be responsible for the irregular distribution of the preservative. Furthermore, the inability to create continuous and frequent interstitial spaces due to the collapse of thin-walled ray cells throughout the lumber resulted in un-even distribution of preservatives. Staining techniques were useful to localize places with more or less abundance of extractives (e.g., fats) in impregnated and unimpregnated wood, which varied considerably. Histochemical observations revealed information pertaining to the kiln dry specific distribution and redistribution of extractives between the areas. Moreover, resin reallocation and modification in ray parenchyma and resin canals induced by kiln drying would be another reason for the impregnation anomalies.


Trees ◽  
2008 ◽  
Vol 22 (6) ◽  
pp. 815-823 ◽  
Author(s):  
Regino Kask ◽  
Katri Ots ◽  
Malle Mandre ◽  
Jaak Pikk

2011 ◽  
Vol 68 (7) ◽  
pp. 1233-1243 ◽  
Author(s):  
Jaume Gort-Oromi ◽  
Lauri Mehtätalo ◽  
Heli Peltola ◽  
Ane Zubizarreta-Gerendiain ◽  
Pertti Pulkkinen ◽  
...  

2019 ◽  
Vol 78 (1) ◽  
pp. 143-150 ◽  
Author(s):  
Harri Mäkinen ◽  
Heikki Korpunen ◽  
Antti Raatevaara ◽  
Jere Heikkinen ◽  
Juha Alatalo ◽  
...  

AbstractStem shapes and wood properties are typically unknown at the time of harvesting. To date, approaches that integrate information about past tree growth into the harvesting and bucking process are rarely used. New models were developed and their potential demonstrated for stem bucking procedures for cut-to-length harvesters that integrate information about external and internal stem characteristics detected during harvesting. In total 221 stems were sampled from nine Scots pine (Pinus sylvestris L.) stands in Finland. The widths of rings 11−20 from the pith were measured using images taken from the end face of each butt log. The total volume of knots in each whorl was measured by using a 4D X-ray log scanner. In addition, 13 stems were test sawn, and the diameters of individual knots were measured from the sawn boards. A model system was developed for predicting the horizontal diameter of the thickest knot for each whorl along a stem. The first submodel predicts the knot volume profile from the stem base upwards, and the second submodel converts the predicted knot volume to maximum knot diameter. The results showed that the knottiness of stems of a given size may vary greatly depending on their early growth rate. The developed system will be used to guide logging operations to achieve more profitable bucking procedures.


Forests ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 587 ◽  
Author(s):  
Benas Šilinskas ◽  
Iveta Varnagirytė-Kabašinskienė ◽  
Marius Aleinikovas ◽  
Lina Beniušienė ◽  
Jūratė Aleinikovienė ◽  
...  

Background and Objectives: The aim of this study was to determine the effects of different stand densities on wood density (WD), global modulus of elasticity (MOE), and bending strength (MOR) in 35-year-old Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) H. Karst) stands, representing the hemiboreal forest zone. Materials and Methods: Scots pine and Norway spruce sites, representing different stand densities of 3000–3100; 2000–2100 and 1000–1100 trees per hectare, were chosen. Visually healthy model pine and spruce trees were selected, and diameter at breast height (DBH) was measured for model trees; the competition index was calculated; the MOE and MOR were evaluated by the Standards EN 408:2006 and EN 384:2016, at 12% moisture content; WD and the knot diameter were measured; and the strength class of wood was determined by the Standard EN 338:2009. To predict wood quality characteristics based on stand and tree characteristics, linear regression models were developed. Results and Conclusions: Higher stand density led to a significant change in the main wood properties of both conifer species. The highest mean WD, MOE, and MOR were obtained at the sites with the highest stand density. The MOE and MOR were highly correlated, but relatively weak correlations were found between MOE and MOR with tree DBH and WD. Despite the lower quality of Scots pine wood, the Norway spruce wood from more dense sites corresponded to the strength class of C16, according the strength grading of softwoods. The linear regression models did not perform well in describing the relationship of wood properties with stand and tree characteristics. The models for MOR accounted for the highest variation of 62–65% for both Scots pine and Norway spruce. These relationships can be expected to change with increased stand age or with the inclusion of specific crown parameters.


2009 ◽  
Vol 66 (8) ◽  
pp. 806-806 ◽  
Author(s):  
Ane Zubizarreta Gerendiain ◽  
Heli Peltola ◽  
Pertti Pulkkinen ◽  
Seppo Kellomäki

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