Articles containing the keyword 'basic density'
Category : Article
The basic density of the wood of the rowan tree (Sorbus aucuparia L.) is almost the same along the stem but that of the bark is increasing along the stem. The moisture content of the wood and of the bark is increasing along the stem. Its strength in the bending and in the compression is high. The volume shrinkage is high.
The PDF includes an abstract in Finnish
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Maasalo,
E-mail:
km@mm.unknown
Norway spruce (Picea abies (L.) H. Karst.) boards sawn from outer layers of logs were sampled from a sawmill in Northern Finland and another in Southern Finland. Test pieces 20 mm x 20 mm x 20 mm were selected according to maximum variation in growth ring width. Volumetric and longitudinal shrinkage from a soaked to a dry condition were measured. It was found that wood density correlated positively with the volumetric shrinkage but negatively with the longitudinal shrinkage. Dry density was a better predictor than basic density. With constant density and an increase in growth ring width, there was increased shrinkage, especially in samples from Northern Finland. Besides this, when density was kept constant, the shrinkage was higher in the spruce wood from Southern Finland than from Northern Finland.
The PDF includes a summary in Finnish.
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Kärkkäinen,
E-mail:
mk@mm.unknown
- Marcus, E-mail: mm@mm.unknown
The effect of growth rate on wood basic density in even-age Norway spruce (Picea abies (L.) H. Karst.) plantations was studied on the basis of samples collected from 53 stands; 30 trees were sampled in each stand. The prediction of basic density with the help of growth rate and some other tree characteristics could be improved if the social status of the tree was taken into account. Within a stand, the smaller trees had a lower density, while taller trees had a higher density than they should have had on the basis of growth rate alone.
The PDF includes a summary in Finnish.
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Kärkkäinen,
E-mail:
mk@mm.unknown
Basic density and absorbed energy in impact bending were measured for 500 Norway spruce (Picea abies (L.) H. Karst.) samples from Northern and Southern Finland. Statistical analysis showed that the relationship between impact strength and basic density was significant and regression analysis showed that it was linear.
Furthermore, with constant density, the impact strength was higher in Northern than in Southern Finland. This was due to growth ring width: i.e. when density was kept constant the impact strength increased with decreasing growth ring width. In addition, when the growth ring width was kept constant, the basic density of wood was higher in Southern Finland than in Northern Finland.
The PDF includes a summary in English.
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Saranpää,
E-mail:
ps@mm.unknown
Empirical measurements showed that the strength of a dead branch of Scots pine (Pinus sylvestris L.) was related to the second power of the branch diameter and the third power of the basic density of branch wood. The same factors affected also the strength of living branches. Especially, the contribution of wood density was important. The significance of the results is discussed considering the natural process of self-pruning and its effect on the branchiness of the stem.
The PDF includes a summary in English.
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Kellomäki,
E-mail:
sk@mm.unknown
A population consisting of 450 Norway spruce (Picea abies (L.) H. Karst.) samples was gathered from northern and southern Finnish wood. The static bending strength was affected greatly by the density of the wood. However, keeping the density constant, the bending strength was higher in northern than in southern Finnish wood. The reason was the effect of the growth ring width.
The basic density was affected by the growth rate. Keeping the growth ring width constant, the basic density was over 5 kg/m3 lower in northern than in southern Finnish wood. This result supports the earlier findings on the effect of latitude.
The PDF includes a summary in English.
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Kärkkäinen,
E-mail:
mk@mm.unknown
- Dumell, E-mail: od@mm.unknown
Eighty Betula nana samples were collected from three swamp sites. In the butt portion of the dwarf shrub the average number of growth rings was 12 and the average diameter of the sprouts 6 mm. The basic density of wood was 457 kg/m3 and that of bark 544 kg/m3. The proportion of bark was 32–38% of weight or volume. The vessel elements and fibres were short and their diameter small. The proportion of vessels was 15%, that of fibres 70% and that of rays 15%.
The PDF includes a summary in Finnish.
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Bhat,
E-mail:
kb@mm.unknown
- Kärkkäinen, E-mail: mk@mm.unknown
The anatomical variation of a lateral root was compared with that of the stem of the same tree at breast height by concentrating on the intrelationships of certain anatomical features in Betula pendula and B. pubescens. The results showed that root wood has several essential features of stem wood, such as gelatinous fibres, growth eccentricity, scalariform perforation plates in the vessels and pith flecks. However, some of the anatomical differences are significant. The differences between the species were more pronounced in the root than in the stem anatomy.
The PDF includes a summary in Finnish.
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Bhat,
E-mail:
kb@mm.unknown
- Kärkkäinen, E-mail: mk@mm.unknown
Ten trees of mountain birch (Betula tortuosa Ledeb, now Betula pubescens subsp. czerepanovii) with an average age of 39 years were sampled in northern Lapland in Finland. The average green density of wood was 589 kg/m3 and that of bark 941 kg/m3. The basic densities were 520 kg/m3 and 559 kg/m3, respectively. The basic density increased only little from the pith to the surface. In contrast, the number of bars in the perforation plates of the vessels increased considerably in the same direction. The average number of bars was 17.3.
The PDF includes a summary in Finnish.
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Bhat,
E-mail:
kb@mm.unknown
- Kärkkäinen, E-mail: mk@mm.unknown
Downy birch (Betula pubescens Ehrh.) trees growing on a drained peatland were cut during dormancy. The properties of the one-year old shoots produced by the stumps were measured in the autumn after one growing season. The one-year old willow shoots (a mixture of Salix phylicifolia L., S. pentandra L. and S. caprea L.) were collected from an abandoned field.
The basic density of unbarked shoots was 443 kg/m3 for birch and 346 kg/m3 for willow. The basic density of the bark was much higher than that of the wood. The effect of shoot length on the properties was small with the exception of cellular proportions. The fibre percentage increased and vessel percentage decreased with increasing shoot length.
The PDF includes a summary in Finnish.
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Bhat,
E-mail:
kb@mm.unknown
- Ferm, E-mail: af@mm.unknown
- Kärkkäinen, E-mail: mk@mm.unknown
Crown and stem growth of young Scots pines (Pinus sylvestris L.) were studied in relation to photosynthate supply and light condition in a stand. The magnitude of needle and bud formation, and radial and height growth were to a great extent dependent on the photosynthate supply. However, in shaded conditions the growth of each characteristics was greater than expected on the basis of photosynthate supply. In the stem system this was especially apparent for height growth. Consequently, height growth was favoured at the expense of radial growth in shaded conditions. It also appeared that the basic density of wood was negatively related to both tree position and photosynthate supply.
The PDF includes a summary in Finnish.
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Kellomäki,
E-mail:
sk@mm.unknown
- Kanninen, E-mail: mk@mm.unknown
The study concerned with variations in the density of the wood of different provenances in provenance test series of Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) RH. Karst.), established in 1931. Increment cores were collected from 10 sample trees from each sample block. The density of the pine wood was noticeably higher than that of spruce. The basic density was in average 450 kg/m3 for Scots pine, and the variation between different origins was 3–9%, while the average basic density of spruce was under 400 kg/m3 and the variation 3–10%. Statistically significant differences were found between the mean basic densities of different provenances in all sub-experiments for spruce, but only in one pine sub-experiment. However, these differences were not due to the altitude or latitude of the place of the origin. Volume growth seems to be the dominant component in the formation of dry matter yield.
The PDF includes a summary in Finnish.
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Velling,
E-mail:
pv@mm.unknown
The effect of solar radiation and air temperature on the basic density of Scots pine (Pinus sylvestris L.) wood has been investigated on the basis of material obtained from the literature. Solar radiation seemed to affect basic density during earlywood formation. Temperature had the greatest effect on basic density in late summer. The varying effects of radiation and temperature seemed to be associated with the dynamics of the crown system of trees. Especially the capacity of the crown system to produce the amount of photosynthesis needed in tracheid growth is assumed to be of importance in controlling the variation in the basic density of Scots pine wood. Growth of thracheids from the point of view of photosynthate supply is discussed.
The PDF includes a summary in Finnish.
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Kellomäki,
E-mail:
sk@mm.unknown
About 100 years old larch (Larix sibirica Lebed. And L. decidua Mill.) trees were felled and the basic density samples taken from the stump level were determined. The number of trees was 21 and number of samples 378. The maximum basic density was reached at the age of 40–60 years, as counted from the pith. The basic density decreased as the width of the growth rings increased or the amount of heartwood decreased. The average basic density of the whole disc was 543 kg/m3 in L. sibirica and 497 kg/m3 in L. decidua. The basic densities of bark were 328 kg/m3 and 286 kg/m3, respectively.
The PDF includes a summary in English.
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Kärkkäinen,
E-mail:
mk@mm.unknown
In this study two methods of determining the basic density of total tree chips are compared. The method of Mäkelä (1977) is based on the volumes of Scots pine, Norway spruce, birch, and alder in a logging area, and the age of the trees. In the other method the basic density of total tree chips is measured by the common displacement method. The correlation was 0,730 in the material of 22 logging areas. Besides this it was found that the basic density of chips increases as the size of the chip particles increases with the exception of the smallest particles.
The PDF includes a summary in English.
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Kärkkäinen,
E-mail:
mk@mm.unknown
A method is presented in this study for calculating the basic density of whole tree- and logging residue chips and the results of trial measurements on some commonly used chip sorts. The basic density of Scots pine whole tree chips was found to be 1–18 kg/m3 smaller than that of pine pulpwood of the same age. The basic density of Norway spruce whole tree chips was 4–22 kg/m3 greater than that of similar aged pulpwood. The basic density of birch whole tree chips was 4–16 kg/m3 and grey alder whole tree chips 7–24 kg/m3 greater than pulpwood of the same age. The basic density of conifer logging residue chips was considerably greater than that of pine and spruce whole tree ships.
The PDF includes a summary in English.
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Mäkelä,
E-mail:
mm@mm.unknown
The paper describes a method for the measurement of basic density of total tree chips. In the method the chips are placed in a container, which is immersed in a cylinder full of water, and the container is weighted at two levels. In the upper part of the cylinder the pressure against the air bubbles is smaller than in the lower level. In this method, the effect of air bubbles in the result can be eliminated. Besides this, due to homogenization of the material to be measured only small number of samples are needed for the estimation of the average basic density.
The PDF includes a summary in English.
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Kärkkäinen,
E-mail:
mk@mm.unknown
Category : Article
Earlier research has presented contradictory results of the influence of forest site type on the weight of wood. In this study, dominant trees of Scots pine (Pinus sylvestris L.) was chosen as sample trees on four forest site types: Calluna, Vaccinium, Myrtillus and Oxalis site types. The trees were felled in autumn, when the water content of the wood is low. Weight of the test samples was measured weigh before and after drying. Undried wood, both sapwood and heartwood, is heavier in Myrtillus type than in Vaccinium type. The weight of the air-dried heartwood did not differ between the two forest site types. Air-dried- sapwood was heaviest in Myrtillus site type. Air-dried heartwood was heaviest in Vaccinium site type, and lightest in Oxalis type. Owen-dried sapwood was heaviest in Calluna site type, where the tree growth is slow, but weight differences were small in owen-dried heartwood. It can be claimed that forest type affects wood quality.
The PDF includes a summary in English.
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Lassila,
E-mail:
il@mm.unknown
Category : Research article
To preliminary evaluate the potential wood utilization of Betula platyphylla Sukaczev trees naturally regenerated in Mongolia, growth characteristics (stem diameter and tree height), wood properties (annual ring width, basic density, and compressive strength parallel to grain at the green condition) of core samples, and stress-wave velocity in stems were investigated for Betula platyphylla trees grown naturally in three different sites in Selenge, Mongolia. Betula platyphylla trees, naturally grown in Nikko, Japan, were also examined to compare wood properties between the two regions. The mean values of stem diameter, tree height, stress-wave velocity of stems, annual ring width, basic density, and compressive strength parallel to grain at green condition in Mongolian B. platyphylla were 17.6 cm, 14.1 m, 3.50 km s–1, 1.27 mm, 0.51 g cm–3, and 20.4 MPa, respectively. Basic density and compressive strength were decreased first from the pith, and then gradually increased toward the bark. The wood properties of B. platyphylla trees grown naturally in Mongolia were similar to those in B. platyphylla trees grown in Japan. Growth characteristics, especially stem diameter, were positively correlated with the stress-wave velocity of stems and basic density. Early evaluation of basic density in B. platyphylla trees is possible by using wood located 2 cm from the pith. Basic density at the position from the 1st to the 15th annual ring from the pith showed significant between-site differences in Mongolian B. platyphylla. Based on the results, it is concluded that the wood of B. platyphylla trees grown in Mongolia may be used for industrial products as well as those from similar species in other countries.
- Erdene-Ochir , School of Agriculture, Utsunomiya University, Utsunomiya, Tochigi 321-8505, Japan; United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology, Fuchu, Tokyo 183-8509, Japan; Training and Research Institute of Forestry and Wood Industry, Mongolian University of Science and Technology, Ulaanbaatar 14191, Mongolia E-mail: togtokhbayarerdeneochir@gmail.com
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Ishiguri,
School of Agriculture, Utsunomiya University, Utsunomiya, Tochigi 321-8505, Japan
E-mail:
ishiguri@cc.utsunomiya-u.ac.jp
- Nezu, School of Agriculture, Utsunomiya University, Utsunomiya, Tochigi 321-8505, Japan E-mail: zoo-sk3.primo@outlook.jp
- Tumenjargal, School of Agriculture, Utsunomiya University, Utsunomiya, Tochigi 321-8505, Japan; United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology, Fuchu, Tokyo 183-8509, Japan; Training and Research Institute of Forestry and Wood Industry, Mongolian University of Science and Technology, Ulaanbaatar 14191, Mongolia E-mail: t_bayasaa88@yahoo.com
- Baasan, Training and Research Institute of Forestry and Wood Industry, Mongolian University of Science and Technology, Ulaanbaatar 14191, Mongolia E-mail: bayartsetseg@must.edu.mn
- Chultem, Training and Research Institute of Forestry and Wood Industry, Mongolian University of Science and Technology, Ulaanbaatar 14191, Mongolia E-mail: ganbaatar_ch@must.edu.mn
- Ohshima, School of Agriculture, Utsunomiya University, Utsunomiya, Tochigi 321-8505, Japan E-mail: joshima@cc.utsunomiya-u.ac.jp
- Yokota, School of Agriculture, Utsunomiya University, Utsunomiya, Tochigi 321-8505, Japan E-mail: yokotas@cc.utsunomiya-u.ac.jp
Geographic variations in growth, stress-wave velocity of stem, dynamic Young’s modulus of stems and logs, annual ring width, latewood percentage and basic density were investigated for Larix sibirica (Münchh.) Ledeb. naturally grown in Mongolia. A total of 250 trees with 20 to 30 cm in stem diameter at a height of 1.3 m above ground level were selected from each natural stand in five different provenances in Mongolia. In addition, five trees in each stand were cut for measuring dynamic Young’s modulus of stems and logs, annual ring width, latewood percentage and basic density. Mean values of stress-wave velocity of stems in each stand ranged from 2.92 to 3.41 km s–1, and the mean value of five stands was 3.23 km s–1. Mean values of dynamic Young’s modulus of logs in each stand ranged from 5.17 to 9.72 GPa. A significant correlation (r = 0.798, p < 0.01) was found between stress-wave velocity of stems and dynamic Young’s modulus of logs. Among the five stands, the highest and the lowest values of average annual ring number were 193 and 44, respectively. Mean values of basic density in five trees within each stand were examined and ranged from 0.52 to 0.56 g cm–3. Significant differences among five stands were found in tree height, stress-wave velocity of stem, dynamic Young’s modulus of stems and logs, annual ring width and latewood percentage, suggesting that L. sibirica trees naturally grown in Mongolia have geographic variations in mechanical properties of wood.
- Tumenjargal, Faculty of Agriculture, Utsunomiya University, Utsunomiya, Tochigi 321-8505, Japan; United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology, Fuchu, Tokyo 183-8509, Japan; Research and Training Institute of Forestry and Wood Industry, Mongolian University Science and Technology, Ulaanbaatar 14191, Mongolia E-mail: t_bayasaa88@yahoo.com
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Ishiguri,
Faculty of Agriculture, Utsunomiya University, Utsunomiya, Tochigi 321-8505, Japan
E-mail:
ishiguri@cc.utsunomiya-u.ac.jp
- Aiso-Sanada, Forestry and Forest Products Research Institute, Tsukuba, Ibaraki 305-8687, Japan E-mail: haiso@ffpri.affrc.go.jp
- Takahashi, Faculty of Agriculture, Utsunomiya University, Utsunomiya, Tochigi 321-8505, Japan E-mail: zo.r.by0814@gmail.com
- Baasan, Research and Training Institute of Forestry and Wood Industry, Mongolian University Science and Technology, Ulaanbaatar 14191, Mongolia E-mail: bayartsetseg@must.edu.mn
- Chultem, Research and Training Institute of Forestry and Wood Industry, Mongolian University Science and Technology, Ulaanbaatar 14191, Mongolia E-mail: ganbaatar_ch@must.edu.mn
- Ohshima, Faculty of Agriculture, Utsunomiya University, Utsunomiya, Tochigi 321-8505, Japan E-mail: joshima@cc.utsunomiya-u.ac.jp
- Yokota, Faculty of Agriculture, Utsunomiya University, Utsunomiya, Tochigi 321-8505, Japan E-mail: yokotas@cc.utsunomiya-u.ac.jp
Hybrid aspen (Populus tremula × P. tremuloides) is one of the fastest growing tree species in Finland. During the mid-1990s, a breeding programme was started with the aim of selecting clones that were superior in producing pulpwood. Hybrid aspen can also be grown as a short-rotation crop for bioenergy. To study clonal variation in wood and bark properties, seven clones were selected from a 12-year-old field trial located in southern Finland. From each clone, five trees were harvested and samples were taken from stem wood, stem bark and branches to determine basic density, effective heating value, moisture and ash content. Vertical within-tree variation in moisture content and basic density was also studied. The differences between clones were significant for almost all studied properties. For all studied properties there was a significant difference between wood and bark. Wood had lower ash content (0.5% vs. 3.9%), basic density (378 kg m–3 vs. 450 kg m–3) and effective heating value (18.26 MJ kg–1 vs. 19.24 MJ kg–1), but higher moisture content (55% vs. 49%) than bark. The values for branches were intermediate. These results suggest that the properties of hybrid aspen important for energy use could be improved by clonal selection. However, selecting clones based on fast growth only may be challenging since it may lead to a decrease in hybrid aspen wood density.
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Hytönen,
Natural Resources Institute Finland (Luke), Natural resources, Teknologiakatu 7, FI-67100 Kokkola, Finland
E-mail:
jyrki.hytonen@luke.fi
- Beuker, Natural Resources Institute Finland (Luke), Production systems, Vipusenkuja 6, FI-57200 Savonlinna, Finland E-mail: egbert.beuker@luke.fi
- Viherä-Aarnio, Natural Resources Institute Finland (Luke), Production systems, Latokartanonkaari 9, FI-00790 Helsinki, Finland E-mail: anneli.vihera-aarnio@luke.fi
Silver birch (Betula pendula Roth) seed origins from the Baltic countries and from Finland were compared in terms of growth, wood density, bark thickness and the incidence of darkened core wood, frost cracks and decay, and the effect of seed origin latitude was examined in two Finnish provenance trials. The material consisted of 21 stand and single tree origins ranging from latitudes 54° to 63°N from the Baltic countries and Finland. The trials, measured at the age of 22 years, were located at Tuusula (60°21´N), southern Finland and at Viitasaari (63°11´N), central Finland. The Baltic origins were superior to the Finnish ones in the southern trial regarding height, whereas in central Finland the Finnish origins grew better. There was no consistent difference between the Baltic and the Finnish group of origins in wood density. Bark thickness decreased with increasing seed origin latitude. The Baltic origins had significantly thicker bark than the Finnish origins. A moderate positive correlation was detected between the seed origin latitude and the incidence of darkened core wood in the southern trial, where the darkened core wood was more common in the Finnish origins than in the Baltic ones. The highest proportion of trees with frost cracks was detected in the south-western Latvian origins growing in central Finland. Seed transfers from the Baltic would have an increasing effect on the bark thickness of birch logs, but no or only minor effects on wood density. Based on our results, there is no reason to recommend the use of non-native Baltic seed origins in Finland instead of the native locally adapted seed sources.
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Viherä-Aarnio,
Natural Resources Institute Finland (Luke), Green technology, P.O. Box 2, FI-00791 Helsinki, Finland
E-mail:
anneli.vihera-aarnio@luke.fi
- Velling, E-mail: pike.velling@phnet.fi
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Pérez,
Ambiente Tierra S.A., Apartado 733-2250, Tres Ríos, Cartago, Costa Rica
E-mail:
diegoperez@costarricense.cr
- Kanninen, Center for International Forestry Research (CIFOR), Bogor, Indonesia E-mail: mk@nn.id
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Lindström,
University of Canterbury, School of Forestry, Private Bag 4800, Christchurch, New Zealand
E-mail:
lindstromhakan@netscape.net
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Johansson,
Swedish University of Agricultural Sciences, Department of Forest Management and Products, P.O. Box 7060, S-750 07 Uppsala, Sweden
E-mail:
tord.johansson@sh.slu.se
