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Major border trade timber tree species and identification in Yunnan Province

PubDate:2014-06-20   Views:1021

Yunnan Province is located on the southwestern frontier of China, bordering Vietnam, Laos, and Myanmar, and is the channel connecting China to Southeast Asia. Yunnan Province is a major forestry province in China. Since the ban on logging of natural forests, border trade timber has become the main source of timber in Yunnan Province.


Vietnam


Vietnam is located south of the Tropic of Cancer, with a hot, humid climate and fertile land, which is conducive to the growth of various plants. Vietnam's forest area is 9.315 million hectares, accounting for about 22% of the country's total area. Distribution of tropical rain forest, tropical deciduous monsoon forest, subtropical forest and mixed coniferous and broad-leaved forest. There are various types of plants, including more than 200 families, more than 1,000 genera, and more than 7,000 species. Among them, precious woods such as ebony, nanmu, lattice wood, teak, and iron wood are important commodities for exporting foreign exchange in Vietnam. Vietnam has a lot of precious wood, with an annual output of 950,000 cubic meters of wood. It borders Yunnan and Guangxi in China. However, in order to protect forest resources and increase the added value of product exports, the Vietnamese government prohibits the export of logs, and only a small amount of wood enters China through border trade.


Main border trade timber


Clam Burretiodendron hsienmu Chun et how (commonly known as Ironwood)


Clam Burretiodendron Rehd. Tiliaceae


Large evergreen tree, bark grayish-brown to dark brown, smooth or shallowly fissured, epidermis peeling off in flakes. Heartwood reddish-brown to dark reddish-brown, inconspicuous or slightly conspicuous growth rings, with light or dark bands between the rings. The tube holes are slightly less, slightly small to medium, white spots under the naked eye, visible under a magnifying glass; quite consistent in size, evenly distributed (diffuse-porous wood), oblique or scattered. Axial parenchyma is small, near tubular. The wood rays are at most, even fine to medium. The wood grain is obliquely interlaced, very heavy and very hard.


Styrax tonkinensis (Pierre) Creib. ex H.


Benzoin Genus Styrax L Benzoinaceae Styracaceae.


Evergreen trees. The bark is gray-black, with white patches, with fine longitudinal cracks on the surface. The sapwood is yellowish white, and the difference between the heart and the sapwood is not obvious. Shiny, no special smell and taste. The growth rings are slightly obvious, with dark lines between the rings. Tube holes are slightly less to medium, slightly smaller to medium; scattered porous wood to semi-ring porous wood; diameter row or scattered; no invasion body is seen. Axial parenchyma was not seen. Most of the wood rays; very fine to medium, obvious under a magnifying glass; there are very fine ray markings on the radial section, which are not obvious. The grain is straight; the structure is very fine and uniform; light and soft.


Eucalyptus citriodora Hook.f.


Eucalyptus L’Herit. Myrtaceae


Large evergreen tree with straight trunk, grayish white and smooth bark. The difference between the heartwood and sapwood is slightly obvious, and the heartwood is dark yellowish brown. Fresh wood has a sour odor. The growth rings are slightly obvious, with dark bands between the rings. Tube holes are few to slightly less, slightly small to medium, visible to the naked eye; slightly uniform in size (diffuse-porous wood), uneven distribution; oblique cracks or zigzag. The axial parenchyma resembles a ring tube bundle. Most of the wood rays, very fine and very fine. The texture is staggered, the structure is fine, and the material is hard and heavy.



Laos


Laos is located inland and has an inland tropical monsoon climate. The year is clearly divided into two seasons (rainy season and dry season).


Laos is the country with the largest proportion of forest area and the most precious wood in the world. The forest area is 14-15 million hectares. Laos borders Jiangcheng County and Mengla County in Yunnan, with a short border. The amount of border trade timber is small.


Main border trade timber


Southwestern birch Betula alnoides Buch.-Ham. ex D. Don


Betula L. Betulaceae


Deciduous trees. The bark is greenish-brown to reddish-brown, peeling off in a paper-like transverse direction. The wood is reddish-brown to gray-brown, the difference between the heart and the sapwood is not obvious, the growth rings are slightly obvious or obvious, and the boundaries between the rings are thin lines. Tube holes are slightly less, slightly small to medium, evenly distributed (diffuse-porous material). Axial parenchyma was not seen. The wood rays are few to medium; very fine to slightly fine, clear under a magnifying glass; there are very fine ray markings on the radial section. Straight grain, fine structure, uniform, medium hardness.


Pterocarpus macrocarpus Kurz, commonly known as rosewood


Pterocarpus Linn. Papilionaceae


Big tree. Heartwood is light red to dark brick red with dark streaks; heartwood and sapwood are distinctly off-white. Growth rings slightly to distinct. Diffuse-porous wood or semi-ring porous wood; tube pores are visible to the naked eye to slightly obvious; few to slightly less; slightly larger; with gum or sediment. Axial parenchyma is numerous, mainly in the form of peritubular band (located outside the growth ring) and annular tubular. Visible under a wooden ray magnifying glass; medium to slightly dense; very narrow. The wood is glossy; the grain is staggered; the structure is uniform. Wood weight (density 0.80~0.86g/cm3); hard; high strength.


Pometia tomentosa Teysm et Binn.


Longan Pometia J.R.et G.Forst. Sapindaceae


Large evergreen tree. Bark dark red, smooth to slightly rough, not split. The wood is light reddish-brown to reddish-brown, the heartwood and sapwood are indistinguishable, and the inner wood is slightly darker. The growth rings are obvious, with dark bands between the rings. The pores are very few at least; medium to slightly large, slightly obvious to the naked eye; uniform in size and slightly evenly distributed (diffuse-porous wood). Axial thin tissue slightly less; wheel boundary and adjacent tubular. Most of the wood rays; even fine or even slightly fine, visible under a magnifying glass; there are very fine ray markings on the radial section. Straight grain, slightly staggered on diameter; fine to medium structure, even, medium weight, medium to slightly hard hardness.



Myanmar 


Myanmar is located in the northwest of Southeast Asia, between the Tibetan Plateau and the Malay Peninsula, bordering India and Bangladesh to the northwest, and to the northeast.


It is adjacent to China and Laos, the southeast is adjacent to Thailand, and the southwest is close to the Bay of Bengal. The terrain is high in the north and low in the south, and the terrain changes greatly. Most of the whole territory has a tropical monsoon climate. The forest coverage rate is 51%, mainly tropical evergreen forests, but there are also alpine coniferous forests in the north. Myanmar is a major producer of high-quality wood teak, and about 75% of the world's natural teak grows in Myanmar. There are also rare tree species such as dipterocarp, ironwood, red sandalwood and mahogany growing in Myanmar. Timber is Myanmar's main export product, and it is an important country in Yunnan Province's timber border trade.


Main border trade timber


(including major border trade timber in Laos)


Simao Pinus kesiya Royle ex Gord.var. langbianensis (A.Chev.) Gaussen


Pinus L. Pinaceae Pinaceae


arbor. The bark is gray-brown, exfoliating in irregular scaly pieces. The sapwood is light yellow or light yellow-brown, and the easy-to-contaminate bacteria are blue-discolored. The wood is shiny and has a strong pine resin smell. The growth ring is very clear, the width is uneven, the latewood band is obvious, and the color is dark. Sooner or later the wood changes rapidly. Axial parenchyma is absent. The wood rays are few to medium, very fine to very fine, clear under a magnifying glass; the ray markings on the radial section are visible to the naked eye. There are many resin channels, distributed in the morning and evening wood, with light spots on the cross section and dark brown stripes on the radial or chord section. The wood structure is medium to coarse, uneven, of medium density and soft.


Hemlock Tsuga dumosa (D.Don)Eichl.


Hemlock Tsuga Carr. Pinaceae Pinaceae


arbor. The bark is thick, gray-brown or dark gray-brown, soft, longitudinally cracked and exfoliated in irregular layered flakes. The wood is yellowish-white to light yellowish brown and reddish, and the difference between the heart and sapwood is not obvious. The growth ring is clear and the latewood is dark. The early wood to late wood changes slightly, and the boundary between early wood and late wood is slightly obvious. Axial parenchyma is absent. The wood rays are subtle or even subtle, clear under a magnifying glass; the ray markings are slightly obvious on the radial section. The normal resin canal is absent, and there are chordwise arranged wound axial resin canals. The grain of the wood is straight and uniform, the structure is fine to medium, and the texture is light and soft.


Southwest alder Alnus nepalensis D.Don commonly known as eastern melon


Alnus Alnus Hill. Betulaceae


The bark is dark green when young, gray-brown when old, irregularly deeply fissured. The wood is light reddish brown, and the difference between the heart and sapwood is not obvious. Growth rings slightly distinct. The tube holes are slightly more, medium to slightly less, slightly visible under the naked eye, and clear under the magnifying glass; the size is the same (scattered porous material), and the distribution is uneven; the diameter is columnar. Axial parenchyma was not seen. The wood rays are at most; the wood rays are divided into two categories, wide and narrow, and the narrow wood rays are slightly visible under a magnifying glass; the broad wood rays (polymerized wood rays) are obvious on the cross section under the naked eye, and brown longitudinal stripes appear on the chord section, and form on the radial section. Longitudinal (or oblique) brown markings. Straight texture, fine to medium structure, light and soft.


Dipterocarpus grandiflorus Blanco commonly known as clone


Dipterocarpus Gaertn. Dipterocarpaceae


Large tree, heartwood grayish reddish brown to reddish brown; heartwood and sapwood are slightly different. Sapwood light taupe. Growth rings are indistinct. Diffuse-porous wood; tube holes are obvious to the naked eye, single tube hole; slightly less at least, large to medium, slightly uniform in size, uneven distribution. The infiltrating body was not seen, but the brown gum was visible. Axial parenchyma is minimal at most, paratubular, off-tubular band, or winged around the intercellular tract. Wood rays are visible to the naked eye, thin to medium; slightly wide to narrow. The wood has a weak luster; the grain is straight, the structure is slightly coarse, and the structure is slightly uniform; the weight is medium to slightly heavy, and slightly hard to hard.


Shorea hypochra Hance


Shorea Roxb.ex Gaerth Dipterocarpaceae


Large tree, heartwood white to light yellowish brown; heartwood and sapwood indistinguishable. Growth rings are indistinct. Diffuse-porous material; tube holes are obvious to the naked eye, single tube holes and short-diameter cut compound tube holes; slightly less at least, slightly larger to medium, one to one size, evenly distributed. Infiltrating body and gum were not seen. Axial parenchyma is abundant, annular tube bundle and wing-like, few are scattered and linear. Wood rays sparse to medium; slightly broad to narrow. The wood is slightly shiny; no special smell and taste; the structure is slightly coarse and uniform; the weight is medium.


Ebony Diospyros ebenum Koenig


Diospyros L. Ebenaceae


arbor. The difference between heartwood and sapwood is obvious, the heartwood is black to jet black, and sometimes faint yellowish-brown thin stripes are visible on the longitudinal section; the sapwood is grayish white to light yellowish brown. Growth rings are indistinct. Tube holes are invisible to the naked eye, clear under a magnifying glass, mainly single tube holes, a few short-diameter multiple tube holes, scattered, very few at least in number, very small to slightly small, a little one to one in size; the tube holes often contain dark brown gum. Axial parenchyma is abundant, visible to the naked eye, in the shape of concentric layers of thin-walled tubes, scattered-aggregated. Wood rays can be seen under a magnifying glass, as rosary-like thin white lines or small white spots of varying lengths, dense to very dense, very fine to very fine. The wood has no special smell and taste. The texture is straight or staggered, the structure is very fine and uniform; the material is even hard and heavy (density 0.92~1.19g/cm3).


Dalbergia fusca Pierre black rosewood


Dalbergia Linn.f. Papilionaceae


Deciduous trees. The bark is gray-brown, shallow longitudinally fissured, peeling off in strips. The sapwood is light yellowish brown, the heartwood and sapwood are distinctly different, and the heartwood is dark brown to black. The wood is shiny. The growth rings are indistinct to slightly conspicuous, with dark lines between the rings. The number of tube holes is small, medium to slightly large, visible to the naked eye; the distribution is slightly uniform (diffuse-porous wood). Axial parenchyma is abundant, visible to the naked eye, band-like near the tube, and arranged in concentric layers chordwise. Wood rays are slightly dense to dense, very fine or even fine, obvious under a magnifying glass. The wood structure is fine, uniform, heavy and very hard.


Toona ciliata Roem. Toona M.Roem.


Toona Meliaceae Juss. Meliaceae


Deciduous or evergreen large trees. Bark grayish brown or dark brown, longitudinally fissured, exfoliating in rectangular blocks. The sapwood is light reddish brown, the heartwood is dark reddish brown, and the difference between the heartwood and the sapwood is obvious. The wood is shiny and has an aromatic smell. Growth rings are evident. Tube pores are few, slightly larger or even larger, obvious to the naked eye; gradually decreasing to the outside of the growth ring (semi-ring porous wood); containing reddish-brown gum. Axial parenchyma is obvious under magnifying glass; Wood rays are few to medium; even fine to medium, slightly visible to the naked eye; ray markings on the radial section are obvious. Medium to coarse, slightly uniform structure; light and soft.


Ta's red heart paint Gluta tavoyana Hook. F commonly known as small rosewood


Gluta L Anacardiaceae


arbor. The wood is diffuse porous. The difference between heartwood and sapwood is obvious, the heartwood is bright red to dark reddish brown, the sapwood is light yellow to pink, the growth ring is slightly obvious, and there are dark thin stripes on the longitudinal section. Tube holes are visible to the naked eye, scattered, very few in number, medium to slightly large, mainly single tube holes, a few short-diameter multi-tube holes, slightly one to one in size; with invading body and white sediments. Axial parenchyma is abundant, visible to the naked eye, reddish-brown; wheel-shaped, band-shaped and annular tube bundle-shaped. The wood rays are medium to slightly dense, even fine, and can be seen under a magnifying glass. The wood is shiny and has no special smell and taste. The texture is straight or oblique, the structure is fine and uniform; the material is hard and heavy (density 0.75~0.85g/cm3).


Pterocarpus pedatus Pierre


Pterocarpus Linn. Papilionaceae


arbor. The wood is diffuse-porous to semi-ring porous. Heartwood and sapwood are distinct, reddish-brown to purple-reddish-brown. The sapwood is pale yellow, the growth rings are obvious, and there are dark thin stripes on the longitudinal section. The tube holes are visible to the naked eye, mainly single tube holes, a few short-diameter multi-tube holes, scattered, few in number, slightly small to medium, and different in size; the tube holes contain a lot of reddish-brown gum and white sediments. Axial parenchyma can be seen under a magnifying glass; the amount is large; it is mainly in the shape of a band near the tube, arranged in the chordwise direction of concentric layers, wing-like and wing-like. The wood rays are slightly dense, extremely fine or even fine, and are clear under a magnifying glass. The new cut noodles have aroma, no special taste. The texture is staggered, the structure is even fine and even; the material is hard and heavy (density 0.96~1.01g/cm3).


Teak Tectona grandis L.f.


Teak genus Tectona L. Verbenaceae


Large deciduous tree with straight trunk. The sapwood is yellowish brown and reddish, the heartwood and sapwood are distinctly different, and the heartwood is light brown to dark brown. The wood is shiny and has a slightly pungent odor when first cut; it is oily to the touch. Growth rings are prominent (ring-porous to semi-ring-porous). The earlywood tube holes are slightly larger in the middle, obvious to the naked eye; the latewood tube holes are few, slightly smaller, obvious under the magnifying glass; scattered 

raw or several oblique columns. Axial parenchyma can be seen under a magnifying glass, near tubular and wheel boundary. The number of wood rays is few; even fine to medium, slightly visible to the naked eye; the ray markings are obvious on the radial section.


Dalbergia oliveri Gamb rosewood


Dalbergia L. f. Papilionaceae


Big tree. The heartwood is reddish-brown or light reddish-brown, the heartwood and sapwood are distinctly different, and the sapwood is yellowish white. The growth rings are slightly visible to the naked eye; diffuse-porous or semi-ring porous wood; tube holes are visible to slightly obvious to the naked eye; few; medium to slightly large; different sizes, uneven distribution; scattered; with gums or sediments. The number of axial parenchyma is large, and it is band-shaped near the tube (concentric circles). It can be seen under the wooden ray magnifying glass, narrower than the tube hole; medium to slightly dense; even narrow to narrow. The wood is glossy; the grain is staggered; the structure is fine and uniform. Very heavy (density 1.04g/cm3); very hard; high strength.


Taxu yunnanensis Cheng et L.K.Fu


Taxu L. Taxaceaexa


arbor. The bark is gray-brown, gray-purple or lavender-brown, falling off in scaly flakes. The sapwood is light yellow-brown, the heartwood and sapwood are very distinct, the heartwood is yellow-reddish-brown to purple-reddish-brown, with dark brown stripes on the upper longitudinal section. The wood has a strong luster; it has a slight aroma and a slightly bitter taste. And the growth ring is obvious, the width is very different, often wavy, with dark bands between the rings; the latewood band is extremely narrow; the earlywood to latewood gradually changes; Axial parenchyma was not seen. The number of wood rays is medium; very fine to very fine, not clear under a magnifying glass, and the ray markings are not visible on the radial section. The resin channel is missing. The grain is straight; the structure is very fine and uniform; the weight and hardness are medium.