Physical and mechanical properties and anatomy of metasequoia wood
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Course
Physical and mechanical properties
Institution
Amsterdam University College (AUC)
INTRODUCTION
Metasequoia (Metasequoia glyptostroboides Hu et Cheng) is a fast growing tree
(about 1.7 meters in height a year). The current natural range of Metasequoia is restricted
to a small area of Hupeh province in China, with the largest natural assemblage of trees (an
area of about 2...
Annals of Warsaw University of Life Sciences – SGGW
Forestry and Wood Technology № 95, 2016: 114-119
(Ann. WULS-SGGW, For. and Wood Technol. 95, 2016)
Physical and mechanical properties and anatomy of metasequoia wood
(Metasequoia glyptostroboides Hu et Cheng)
PAWEŁ KOZAKIEWICZ*, SŁAWOMIR MONDER**
*Department of Wood Science and Wood Preservation, **Department of Technology and Entrepreneurship
in Wood Industries, Faculty of Wood Technology, Warsaw University of Life Sciences - SGGW
Abstract: Physical and mechanical properties and anatomy of metasequoia wood (Metasequoia
glyptostroboides Hu et Cheng). Metasequoia glyptostroboides is the only species of the metasequoia genus
preserved to our day. It produces coarse wood with a very small share of late wood. This is a wood of evenly
coloured heartwood and sapwood narrow zone. In its annual rings dominate thin tracheids of the early wood,
what results in a low density. It also has a low shrinkage, but unfortunately also low strength parameters.
Because of its rapid growth metasequoia has potential to be grown on plantations and be used for the
production of wood-based materials.
Keywords: metasequoia wood, anatomy of wood, physical and mechanical properties of wood
INTRODUCTION
Metasequoia (Metasequoia glyptostroboides Hu et Cheng) is a fast growing tree
(about 1.7 meters in height a year). The current natural range of Metasequoia is restricted
to a small area of Hupeh province in China, with the largest natural assemblage of trees (an
area of about 25 km by 1.5 km) in the of the valley Modao river (Jagels et al. 2003). In this
region trees can reach up to 50 meters in height and a few meters in diameter [Florin 1952]
(Florin 1952). Rapid growth is confirmed by observations in other parts of the world.
Metasequoias planted in the United Stated in 50 years reached even 38 meters in height
(Kuser 1999) .Similar observations were also made in specimens found in Poland, which
have been grown here since 1948 (Surmiński and Bojarczuk 1973, Kolasiński 2009).
Metasequoia is also a long-lived tree and it is estimated that it may reach the age
of over 1000 years. This species prefers fertile and well sunlit habitats, but above all
humid: in China it is also known as water fir (Banfi and Consolino 2001).
Metasequoia was found in many fossils dated between 5 to 100 Million years, but it
was usually described as either Taxodium or simply sequoia. Only in 1941 a Japanese
paleobotanist Miki gave the discovered fossilized remains a distinct name of Metassequoia
(Momohara 1994, Kolasiński 2009) In the same year living specimens of these trees were
discovered in China, hence some call this tree a living fossil. After cultivation of several
trees of this species, scientists started to study anatomy and properties of its wood, with
particular attention to the physiology of trees [e.g. Greguss 1955, Hejnowicz 1973,
Surmiński and Bojarczuk 1973, Vischer 2002, Jagles et al.2003]. Still, there are no
in-depth studies about the use of metasequoia wood in the industry.
The object of this article is to study some physical and mechanical properties
of Chinese metasequoia wood and analyse its anatomical structure. Our findings will
contribute to the knowledge of this species of wood, a living fossil in the world of plants,
and identify its potential applications for industry.
114
, MATERIAL AND METHODS
This study used a single withering tree trunk of Chinese metasequoia, obtained as
a part of maintenance works in the Botanical Garden CZRB PAN in Powsin. It was 19
years old, with well-shaped trunk and large convergence. After drying the wood to an air-
dry state, standard samples were cut out, except from the core and the last two annual
increments, to determine its particular physical and mechanical properties.
Determination was carried out according to the procedures for testing the properties
of the small laboratory samples according to Polish standards [PN-D-04117:1963, PN-D-
04103:1968, PN-D-04100:1977, PN-D-04101:1977, PN-D-04102:1979, PN-D-04111:
1982]. Most of the used procedures were also in line with international standards
[ISO 3130:1975, ISO 3131:1975, ISO 3133:1975, ISO 3787:1976, ISO 4858:1982].
We also studied speed of ultrasound transition along the fibres as well as some
dynamic modulus of elasticity using a frequency of 40 kHz. At the same time, several
permanent microscopic preparations presenting three basic anatomical sections
of metasequoia wood were made: preparations with a thickness of 15-20 um, sliced from
plasticized wood soaked in a solution of water, alcohol and glycerine with added safranine,
closed in Canadian balsam and xylene. Observations and measurements of structural
elements were made with an Olympus BX-1 microscope, equipped with a digital camera
and Cell-B* software for image analysis.
RESULTS AND DISCUSSION
In terms of macroscopic construction wood test showed the typical characteristics
of the species analysed in the literature [Greguss 1955, Hejnowicz 1973, Surmiński and
Bojarczuk 1973, Vischer 2002] On the cross-section of the trunk reddish-brown heartwood
is surrounded by a narrow zone of white- yellow sapwood. This is a coarse wood with
an annual growth rings about 7mm in width. The characteristic feature is a very small
proportion of the late wood in annual ring (only about 10% width). The dominant elements
are thin tracheids of early wood with big lights with approx. 1,8 m thickness of walls.
In a radial direction wood tracheids are over 40 in diameter m but in a tangential direction
it is twice less (table 1).
In the radial walls of the tracheids of wood there are numerous cavities funnel
(approx.15 pm in diameter). Sometimes two are stacked on the width of a wall (fig.1b).
Tracheids of late wood (with thicker walls of about 4,5 m) have a diameter of about
22 m and the last rows of the of annual border growth are heavily flattened in the radial
direction (the radial dimension is only 8-10 m) – fig.1a Occurring cavities in the late
wood tracheids have a smaller radial diameter of approx. 9,5 m. The length of tracheids
is rather short: 1.5 - 3 mm (juvenile wood was analysed and it has a shorter structural
elements in comparison to mature wood). The vertical structure of wood is complemented
by a few cells of wood pith with an average length of approx 120 m and varied diameters
of 20 to 50 m.
Wood rays are homogeneous with a single file composed of parenchyma cells
[Greguss1955, Hejnowicz 1973, Surmiński and Bojarczuk 1973]. Occasionally, in some
layers of rays, there are two rows of cells (fig.1c) The number of layers (radius’ height)
is varied and ranges from just a couple to several dozens, even over 30 (usually 5-11 rays
are layered, with a height of approx. 80 to 200 m and a width of approx. 18 m). At the
radial section of the contact rays with vertical elements of the structure exist cupressoid or
taxodioid pits of wood: usually 2-3 (sometimes 4-5) in a single field.
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