PubDate：2014-06-20 Views：817
Yunnan Province is located in the southwestern frontier of China, bordering Vietnam, Laos, and Myanmar, and is a channel connecting China to Southeast Asia. Yunnan Province is a major forestry province in China. After the ban on logging of natural forests, border trade timber has become the main source of timber in Yunnan Province.
Vietnam
Vietnam is located to the south of the Tropic of Cancer, the climate is hot, humid, and the land is fertile, which is conducive to the growth of various plants. The forest area in Vietnam totals 9.315 million hectares, accounting for about 22% of the country's total area. It is distributed in tropical rain forests, tropical deciduous monsoon forests, subtropical forests and mixed coniferous and broad-leaved forests. There are many kinds of plants, there are more than 200 families, more than 1,000 genera, and more than 7,000 kinds. Among them, ebony wood, nanmu, grid wood, teak, iron wood and other precious woods are important commodities for foreign exchange earning in Vietnam. There are many precious woods in Vietnam, with an annual output of 950,000 cubic meters of wood. It borders China's Yunnan and Guangxi. 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 timber enters China through border trade.
Main border trade timber
Clam Burretiodendron hsienmu Chun et how (commonly known as iron wood)
Burretiodendron Rehd. Tiliaceae
Large evergreen tree, the bark is grayish brown to dark brown, smooth or shallowly split, and the epidermis is flaky. The heartwood is reddish brown to dark reddish brown, the growth rings are inconspicuous or slightly obvious, with light or dark bands between the rings. The tube holes are slightly small, slightly small to medium, white spots under the naked eye, visible under a magnifying glass; fairly uniform in size, evenly distributed (scattered porous material), obliquely arranged or scattered. The axial parenchyma is small, and it is adjacent to the tube. Wood rays are at most, very fine to medium. The wood grains are staggered, heavy and hard.
Vietnam benzoin Styrax tonkinensis (Pierre) Creib. ex H.
Benzoin belongs to Styrax L. Styracaceae.
Evergreen trees. The bark is gray-black, with white patches, and there are fine longitudinal cracks on the surface. The sapwood is yellow and white, and the difference between heart and sapwood is not obvious. Luster, no special smell and taste. The growth rings are slightly obvious, with dark lines between them. The pipe holes are slightly small to medium, slightly small to medium; diffuse porosity to semi-annular porosity; radial or scattered; no intrusion is seen. No axial parenchyma was seen. Wood rays are at most; very fine to medium, which is obvious under a magnifying glass; there are very fine ray markings on the radial section, which are not obvious. The texture 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, gray and smooth bark. The difference between heartwood and sapwood is slightly obvious, and the heartwood is dark yellow-brown. Fresh wood has a sour odor. The growth rings are slightly obvious, with a dark band between them. The pipe holes are small to slightly small, slightly small to medium, visible under the naked eye; slightly the same size (diffuse porous material), uneven distribution; oblique cracks or zigzag. The axial parenchyma resembles a bundle of annular tubes. Wood rays are at most, extremely 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 amounts to 14-15 million hectares. Laos borders Jiangcheng County and Mengla County in Yunnan with a short border. The amount of border trade timber is relatively small.
Main border trade timber
Betula alnoides Buch.-Ham. ex D. Don
Betula L. Betulaceae
Deciduous trees. The bark is blue-brown to reddish-brown, and the paper is peeled off horizontally. The wood is reddish-brown to gray-brown, the difference between the heart and sapwood is not obvious, the growth ring is slightly obvious or obvious, and the boundary between the rings is thin. The pipe holes are slightly small, slightly small to medium, and evenly distributed (diffuse porous material). No axial parenchyma was seen. Wood rays are few to medium; very fine to slightly thin, clear under a magnifying glass; there are very fine ray markings on the radial section. The texture is straight, the structure is fine, uniform, and the hardness is medium.
Pterocarpus macrocarpus Kurz, commonly known as rosewood
Pterocarpus Linn. Papilionaceae
Large arbor. The heartwood is light red to dark brick red with dark stripes; the difference between the heartwood and the sapwood is obvious, and the sapwood is gray-white. The growth ring is slightly obvious to obvious. Diffuse porous material or semi-ring porous material; the tube holes can be seen to a little obvious under the naked eye; little to a little bit; slightly larger; with gum or sediment. There are many axial parenchyma tissues, mainly in the shape of the adjacent tube band (located outside the growth ring) and the ring tube. Visible under a wooden ray magnifying glass; medium to slightly dense; very narrow. The wood is shiny; the grains are staggered; the structure is uniform. Wood weight (density 0.80~0.86g/cm3); hard; high strength.
Pometia tomentosa Teysm et Binn. Commonly known as Hong buried Ga
Sapindaceae Pometia J.R.et G.Forst. Sapindaceae
Large evergreen tree. The bark is dark red, smooth to a little rough, not cracked. The wood is light reddish brown to reddish brown, the difference between the heartwood and sapwood is not obvious, and the inner wood is slightly darker. The growth rings are obvious, with dark bands between them. The pipe holes are few at least; medium to slightly larger, slightly obvious to the naked eye; the same size, slightly even distribution (diffuse porous material). Axial thin tissue is slightly less; round circle shape and proximate tube. Wood rays are at most; very fine to slightly thin, visible under a magnifying glass; there are very fine ray markings on the radial section. The texture is straight, the diameter surface is slightly staggered; the structure is fine to medium, uniform, medium weight, and medium to slightly hard.
Myanmar
Myanmar is located in the northwestern part of Southeast Asia, between the Tibet Plateau and the Malay Peninsula, the northwest borders India and Bangladesh, and the northeast
It is adjacent to China and Laos, adjacent to Thailand in the southeast and the Bay of Bengal in the southwest. The terrain is high in the north and low in the south, and the topography changes greatly. Most parts of the territory have a tropical monsoon climate. The forest coverage rate is 51%, dominated by tropical evergreen forests, but there are also alpine coniferous forests in the north. Myanmar is the main producer of high-quality timber teak. About 75% of the world's natural teak grows in Myanmar. Burma also grows rare tree species such as dipterocarp, ironwood, red sandalwood, mahogany and so on. Timber is Myanmar's main export product for foreign exchange earning, and an important country for timber border trade in Yunnan Province.
Main border trade timber
(Including the main border trade timber of Laos)
Pinus kesiya Royle ex Gord.var. langbianensis (A.Chev.) Gaussen
Pinus L. Pinaceae
arbor. The bark is gray-brown, with irregular scaly pieces peeling off. The sapwood is light yellow or yellowish brown, the susceptible bacteria is blue and discolored, the heartwood and sapwood are distinct, and the heartwood is reddish brown or yellowish brown. The wood is shiny and has a strong rosin smell. The growth ring is very clear, the width is uneven, the latewood band is obvious, and the color is deep. Sooner or later the material changes drastically. The axial parenchyma is missing. Wood rays are few to medium, very fine to very fine, clear under a magnifying glass; ray markings on the radial section are visible under the naked eye. There are many resin channels, distributed in the morning and evening wood, with light-colored spots on the cross section, and dark brown stripes on the diameter section or string section. The wood structure is medium to coarse, uneven, medium density, and soft.
Tsuga dumosa (D.Don) Eichl.
Tsuga Tsuga Carr. Pinaceae
arbor. The bark is thick, gray-brown or dark gray-brown, soft in nature, and the longitudinal cracks are flaked off in irregular layers. The wood is yellow-white to pale yellow-brown and reddish, and the difference between heart and sapwood is not obvious. The growth ring is clear, and the latewood band is dark. There is a slight sudden change from early wood to late wood, and the boundary between morning and late wood is slightly obvious. The axial parenchyma is missing. Wood rays are subtle to very subtle, clear under a magnifying glass; rays markings on the radial section are slightly obvious. The normal resin canal is absent, and there are chordally arranged traumatic axial resin canals. The wood texture is straight and uniform, the structure is fine to medium, and the material is light and soft.
Southwest Alnus Alnus nepalensis D. Don, commonly known as Eastern Melon
Alnus Hill. Betulaceae
The bark is dark green when it is young, and grayish brown when it is old, with irregular and deep splits. The wood is light reddish brown, and the difference between heart and sapwood is not obvious. The growth ring is slightly clear. Slightly more pipe holes, medium to slightly less, slightly visible under the naked eye, clear under a magnifying glass; the same size (scattered porous material), uneven distribution; diameter row. No axial parenchyma was seen. The wood rays are at most; wood rays are divided into two types: wide and narrow, narrow wood rays are slightly visible under a magnifying glass; wide wood rays (polymer wood rays) are obvious on the cross section under the naked eye, with brown longitudinal stripes on the chord section, formed on the radial section Longitudinal (or oblique) brown markings. The texture is straight, the structure is fine to medium, light and soft.
Dipterocarpus grandiflorus Blanco, commonly known as clone
Dipterocarpus Gaertn. Dipterocarpus Gaertn. Dipterocarpus Gaertn
Large trees, the heartwood is grayish reddish brown to reddish brown; the difference between the heartwood and the sapwood is slightly obvious. The sapwood is light grayish brown. The growth ring is not obvious. Diffuse porous material; tube holes are obvious to the naked eye, single tube holes; slightly less at least, large to medium, slightly uniform in size, uneven distribution. No intrusion was seen, but brown gum was visible. The axial parenchyma is few to many, adjacent to the tube, ribbon-shaped away from the tube, or wing-shaped around the intercellular tract. Wood rays are visible to the naked eye, sparse to medium; slightly wide to narrow. The luster of the wood is weak; the texture is straight, the structure is slightly coarse, and slightly uniform; the weight is medium to slightly heavy, and slightly hard to hard.
Shorea hypochra Hance
Shorea Roxb.ex Gaerth Dipterocarpaceae Dipterocarpaceae
Large arbor, the heartwood is white to light yellowish brown; the difference between the heartwood and the sapwood is not obvious. The growth ring is not obvious. Diffusion-porous material; the pipe holes are obvious to the naked eye, single pipe holes and short-diameter cut multiple pipe holes; slightly less at least, slightly large to medium, one to one size, uniform distribution. The intrusion body and gum were not seen. The axial parenchyma is abundant, the annular tube is bundled and winged, and a few are scattered and linear. Wood rays are thin to medium; slightly wide to narrow. The wood is slightly shiny; there is no special smell and taste; the structure is slightly coarse and uniform; the weight is medium.
Ebony Diospyros ebenum Koenig
Diospyros L. Diospyros L. Ebenaceae
arbor. The difference between the heartwood and sapwood is obvious. The heartwood is jet-black to jet black, sometimes faintly visible yellowish-brown pinstripes on the longitudinal section; the sapwood is gray-white to pale yellow-brown. The growth ring is not obvious. The tube hole is not visible under the naked eye, but it is clear under a magnifying glass. It is mainly single tube hole, a few short diameter rows of multiple tube holes, scattered, the number is very small at least, very small to slightly smaller, and the size is a little bit; the tube hole often contains dark brown gum. The axial parenchyma is large, visible under the naked eye, in the shape of concentric delaminated tubes, scattered-aggregated. Wood rays can be seen under a magnifying glass, and are rosary-like white thin lines or small white dots of varying lengths, dense to dense, extremely thin to very thin. 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 Dalbergia Linn.f. Papilionaceae
Deciduous trees. The bark is gray-brown, shallow longitudinally cracked, peeling off in strips. The sapwood is light yellowish brown, and the difference between the heartwood and the sapwood is obvious. The heartwood is dark brown to black. The wood is shiny. The growth rings are not obvious to a little obvious, with dark lines between them. The number of tube holes is small, medium to slightly large, visible under the naked eye; the distribution is slightly even (diffuse porous material). There are many axial parenchyma tissues, visible under the naked eye, in a band-like shape near the tube, arranged chordwise in concentric layers. The wood rays are slightly dense to dense, extremely thin to very thin, and they are obvious under a magnifying glass. The wood structure is fine, uniform, heavy, and very hard.
Toona ciliata Roem. Toona M. Roem.
Toona is Meliaceae Juss. Meliaceae
Deciduous or evergreen large trees. The bark is grayish brown or dark brown, longitudinally cracked, and peeling off in rectangular lumps. The sapwood is light reddish brown, the heartwood is dark reddish brown, and the difference between heartwood and sapwood is obvious. The wood is shiny and has a fragrant smell. The growth ring is obvious. The tube holes are few, slightly larger to very large, which are obvious to the naked eye; they gradually decrease toward the outside of the growth ring (semi-annular pores); contain red-brown gum. The axial parenchyma is obvious under a magnifying glass; it is tubular and round-shaped. Wood rays are few to medium; very fine to medium, slightly visible under the naked eye; ray markings on the radial section are obvious. The structure is medium to coarse, slightly uniform; light and soft.
Gluta tavoyana Hook. F, commonly known as small red wood
Gluta L Anacardiaceae
arbor. The wood is diffuse porous wood. The difference between the 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. The tube holes are visible under the naked eye, scattered, the number is very small at least, medium to slightly larger, mainly single tube holes, a few short-diameter rows of multiple tube holes, slightly the same size; with intrusion bodies and white sediments. The axial parenchyma is rich, visible under the naked eye, reddish-brown; round circles, bands and loops. The wood rays are medium to slightly dense, even thin to slightly thin, visible under a magnifying glass. The wood has luster, 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. Wood is diffuse porous to semi-annular porous wood. The difference between heartwood and sapwood is obvious, the heartwood is reddish brown to purple reddish brown. The sapwood is light yellow, the growth ring is obvious, and there are dark pinstripes on the longitudinal section. The tube holes can be seen under the naked eye, mainly single tube holes, a few short-diameter rows of multiple tube holes, scattered, small in number, slightly small to medium, and varying in size; the tube holes contain a large amount of red-brown gum and white sediments. The axial parenchyma can be seen under a magnifying glass; the amount is large; it is mainly in the shape of a lateral tube band, arranged chordwise in concentric layers, wing-like and poly-wing-like. The wood rays are medium to slightly dense, very fine to very fine, and clear under a magnifying glass. The freshly sliced noodles are fragrant and have no special taste. The texture is staggered, and the structure is very fine to fine and uniform; the material is hard and heavy (density 0.96~1.01g/cm3).
Teak Tectona grandis L.f.
Teak is Tectona L. Verbenaceae
Large deciduous tree with straight trunk. The sapwood is yellowish-brown and reddish, and the difference between the heartwood and the sapwood is obvious. The heartwood is light brown to dark brown. The wood is shiny and has a slightly pungent odor when it is first cut; it is oily and sexy to the touch. The growth ring is obvious (annular porosity to semi-annular porosity). Early wood pipe holes are slightly larger and obvious to the naked eye; late wood pipe holes are few, slightly smaller, and are obvious under a magnifying glass; scattered or several oblique rows. The axial parenchyma can be seen under a magnifying glass, and it is tubular and round-shaped. Wood rays are few; very fine to medium, slightly visible under the naked eye; ray markings are obvious on the radial section.
Dalbergia oliveri Gamb rosewood
Dalbergia Dalbergia L. f. Papilionaceae
Large arbor. The heartwood is reddish brown or light reddish brown, the heartwood and sapwood are distinctly different, and the sapwood is yellow and white. Growth rings can be seen slightly under the naked eye; diffuse porosity or semi-ring pore material; tube holes can be seen to a little obvious under the naked eye; few; medium to slightly larger; varying in size and uneven distribution; scattered; with gum or sediment. There are many axial parenchyma tissues, and they are band-shaped (concentric circles) adjacent to the tube. It can be seen under the magnifying glass of wood ray, narrower than the tube hole; medium to slightly dense; very narrow to narrow. The wood is shiny; 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
Taxus genus taxu L. Taxacea taxaceaexa
arbor. The bark is grayish-brown, gray-purple or lavender-brown, with scaly flakes falling off. The sapwood is light yellow-brown, and the difference between the heartwood and the sapwood is very obvious. The heartwood is yellow-red-brown to purplish-red-brown, and there are dark brown band-like stripes in the longitudinal section. The wood has a strong luster; it has a slight aroma and a slightly bitter taste. It is obviously different from the growth ring, and the width is very different. It is often wavy, with a dark band between the wheels; the latewood band is very narrow; the earlywood to latewood gradually changes; the latewood band is dark in color, which is obviously different from the earlywood belt. No axial parenchyma was seen. The number of wood rays is medium; very fine to very thin, not clear under a magnifying glass, and no ray markings on the radial section. The resin canal is absent. The texture is straight; the structure is very fine and uniform; the weight and hardness are medium.
