Moisture Dynamics in Norway Spruce and Scots Pine during Outdoor Exposure in Relation to Different Surface Treatments and Handling Conditions

Holzforschung ◽  
2003 ◽  
Vol 57 (2) ◽  
pp. 219-227 ◽  
Author(s):  
T. Elowson ◽  
M. Bergström ◽  
M. HämälÄinen
Keyword(s):  
Norway Spruce ◽  
Scots Pine ◽  
Principal Component ◽  
Production Method ◽  
Outdoor Exposure ◽  
Moisture Uptake ◽  
High Moisture ◽  
Large Spread ◽  
Handling Method ◽  
Moisture Dynamics

Summary Moisture dynamics in wood during weather exposure as affected by species, origin, production method and painting system were studied for nine years on 170 samples. The moisture content (MC, by dry base) was measured on 67 occasions. Principal component analysis was used for data reduction and pattern recognition. The investigation included two species; Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies L. (Karst)), and showed that the painting method affected the moisture dynamics most. In addition, species and type of wood were important factors, and for pine sapwood also the production method used had an influence on the moisture dynamics. Heartwood of pine had a stable development with low MC throughout the experimental time, regardless of surface treatment or handling method. The pine sapwood samples, on the other hand, had higher average MC and much faster dynamics. For painted and endsealed pine sapwood samples, the drying method was not significant for the MC dynamics, but water storage led to a higher and faster moisture uptake than for samples that were not water-stored. For untreated pine sapwood samples, air-drying led to the highest and fastest moisture uptake, but on the whole this group had unacceptably high moisture uptake. The spruce samples showed very different behaviour depending on whether they were surface treated or not. Painted and endsealed spruce led to two distinct groups, one with moisture dynamics similar to pine heartwood and one with very high moisture uptake and large spread more similar to pine sapwood. Most untreated spruce samples had moisture dynamics comparable to those of pine heartwood.

Mass loss and moisture dynamics of Scots pine (Pinus sylvestris L.) exposed outdoors above ground in Sweden

Holzforschung ◽  
2005 ◽  
Vol 59 (2) ◽  
pp. 183-189 ◽  
Author(s):  
Åsa Rydell ◽  
Mikael Bergström ◽  
Torbjörn Elowson
Keyword(s):  
Moisture Content ◽  
Pinus Sylvestris ◽  
Mass Loss ◽  
Scots Pine ◽  
Annual Ring ◽  
Water Storage ◽  
Ring Width ◽  
Moisture Uptake ◽  
Annual Ring Width ◽  
Moisture Dynamics

Abstract The durability of 566 Scots pine (Pinus sylvestris) samples was tested during a period of 9 years of exposure to weather in Sweden. The parameters investigated were heartwood/sapwood, origin, surface treatment, end-seal, storage and drying method, annual ring width and density. The weight was measured on 67 occasions during 9 years in order to assess the moisture content of the samples. The mass loss was determined for each sample at the end of the trial. Sapwood had a higher moisture uptake and a higher mass loss compared with heartwood. Even if sapwood was painted with an impermeable paint and then end-sealed, it still had higher average moisture content than heartwood. The results also demonstrated that sapwood was more sensitive to different handling conditions than heartwood. Sapwood was sensitive to air-drying and water storage, which was evident in the higher moisture uptake. In terms of mass loss, some differences were evident but they were not statistically significant due to the large standard deviation of the sapwood samples from water-stored logs. The only positive influence of water storage was on samples end-dipped in oil. One explanation could be that water storage led to increased permeability due to bacterial attack, which in turn enhanced the penetration of the oil. Heartwood had low and stable moisture dynamics during the test period, almost independent of treatment or handling conditions. No correlation with moisture uptake or mass loss was evident among annual ring width, origin or density.

scholarly journals Correlation of Studies between Colour, Structure and Mechanical Properties of Commercially Produced ThermoWood® Treated Norway Spruce and Scots Pine

Forests ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 1165
Author(s):  
Petteri Torniainen ◽  
Carmen-Mihaela Popescu ◽  
Dennis Jones ◽  
Alexander Scharf ◽  
Dick Sandberg
Keyword(s):  
Mechanical Properties ◽  
Quality Control ◽  
Norway Spruce ◽  
Scots Pine ◽  
Untreated Wood ◽  
Principal Component ◽  
Thermal Modification ◽  
Small Scale ◽  
Colour Measurements ◽  
Modified Wood

The thermal modification of wood has become the most-commonly commercialised wood modification process globally, with the ThermoWood® process currently being the most dominant. As with all commercial processes, there is a need to have a robust quality control system, with several small–scale studies undertaken to date investigating quality control using a range of analytical methods, culminating in a multi-year assessment of colour as a means of quality control. This study, as an extension to this multi-year assessment, further explores the colour of Norway spruce and Scots pine commercially modified by the ThermoWood® S and D processes, respectively, along with the mechanical properties and structural characterisation by Fourier transform infrared (FT–IR) spectroscopy and principal component analysis (PCA) to ascertain further correlations between colour and other measurable properties. Infrared spectroscopy indicated modifications in the amorphous carbohydrates and lignin, whereas the use of PCA allowed for the differentiation between untreated and modified wood. Colour measurements indicated reduced brightness, and shifting toward red and yellow colours after thermal modification, hardness values decreased, whereas MOE and MOR values were similar for modified wood compared to unmodified ones. However, by combining the colour measurements and PC scores, it was possible to differentiate between the two modification processes (Thermo–S and Thermo–D). By combining the mechanical properties and PC scores, it was possible to differentiate the untreated wood from the modified ones, whereas by combining the mechanical properties and colour parameters, it was possible to differentiate between the three groups of studied samples. This demonstrates there is a degree of correlation between the test methods, adding further confidence to the postulation of using colour to ensure quality control of ThermoWood®.

scholarly journals Growth Responses of Boreal Scots Pine, Norway Spruce and Silver Birch Seedlings to Simulated Climate Warming over Three Growing Seasons in a Controlled Field Experiment

Forests ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 943
Author(s):  
Katri Nissinen ◽  
Virpi Virjamo ◽  
Antti Kilpeläinen ◽  
Veli-Pekka Ikonen ◽  
Laura Pikkarainen ◽  
...  
Keyword(s):  
Norway Spruce ◽  
Scots Pine ◽  
Root Biomass ◽  
Growing Season ◽  
Silver Birch ◽  
Shoot Biomass ◽  
Growth Responses ◽  
Growing Seasons ◽  
Simulated Climate ◽  
Shoot And Root Biomass

We studied the growth responses of boreal Scots pine (Pinus sylvestris L.), Norway spruce (Picea abies L. Karst.) and silver birch (Betula pendula Roth) seedlings to simulated climate warming of an average of 1.3 °C over the growing season in a controlled field experiment in central Finland. We had six replicate plots for elevated and ambient temperature for each tree species. The warming treatment lasted for the conifers for three growing seasons and for the birch two growing seasons. We measured the height and diameter growth of all the seedlings weekly during the growing season. The shoot and root biomass and their ratios were measured annually in one-third of seedlings harvested from each plot in autumn. After two growing seasons, the height, diameter and shoot biomass were 45%, 19% and 41% larger in silver birch seedlings under the warming treatment, but the root biomass was clearly less affected. After three growing seasons, the height, diameter, shoot and root biomass were under a warming treatment 39, 47, 189 and 113% greater in Scots pine, but the root:shoot ratio 29% lower, respectively. The corresponding responses of Norway spruce to warming were clearly smaller (e.g., shoot biomass 46% higher under a warming treatment). As a comparison, the relative response of height growth in silver birch was after two growing seasons equal to that measured in Scots pine after three growing seasons. Based on our findings, especially silver birch seedlings, but also Scots pine seedlings benefitted from warming, which should be taken into account in forest regeneration in the future.

scholarly journals The effects of soil and air temperature on CO2 exchange and net biomass accumulation in Norway spruce, Scots pine and silver birch seedlings

2012 ◽  
Vol 32 (6) ◽  
pp. 724-736 ◽  
Author(s):  
J. Pumpanen ◽  
J. Heinonsalo ◽  
T. Rasilo ◽  
J. Villemot ◽  
H. Ilvesniemi
Keyword(s):  
Norway Spruce ◽  
Scots Pine ◽  
Air Temperature ◽  
Biomass Accumulation ◽  
Co2 Exchange ◽  
Silver Birch
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