Encyclopedia business card The southwestern birch is the southernmost species of birch in the northern hemisphere. It is concentrated in the southwestern, southern, southeastern and western Guangxi, southwestern, northwestern and southern Guizhou regions. These distribution areas are connected with the distribution areas of Vietnam, Laos and Myanmar, forming the central distribution area of ​​southwestern birch. The horizontal distribution range is approximately 97°3′′ to 108°E, 19 to 25°N, and vertically distributed at an altitude of 200 to 2800 meters. Morphological characteristics The maturity of southwestern birch seeds varies from place to place. Yunnan and Guangxi are generally from January to March, and Hainan Island is from April. The seed maturity period is short, and the seed is usually scattered for about 10 days, so the seed collection should be timely. When the ear turns from cyan to yellowish brown, it is mature. The seeds should be cut together with the ears. After 3-5 days of dryness, the seeds will automatically fall off the ears, obtain clean seeds, and store them in the refrigerator for removal. The growth of the southwestern birch seedlings should pay attention to the management of water and fertilizer, especially the management of water. The water in the seedling stage should not be too much, and it should not be short of water. If the soil surface is white, it should be watered. Otherwise, it will be difficult to resume growth and death after the seedlings dry up. The humidity is moistened with nutrient soil, and it is important to avoid excessive watering to cause rotten seedlings. This is an important measure that needs special attention and emphasis. Biological characteristics Betula platyphylla is a strong-positive tree species, which is light-light, not shade-tolerant, and is suitable for acid soil. It has strict requirements on soil fertility and has certain tolerance to barrenness. It grows fast and yields high in the deep, loose and well-drained mountain soils south of 25° north latitude. According to the Tropical Forestry Experiment Center, the average height of 18 years is 18m, the average breast diameter is 21.5cm, and the dominant wooden diameter and tree diameter. The heights are 32.6 cm and 24.0 m, respectively. A plantation forest was built in 2001 by the Yongkeng Forestry Group of our province, and was surveyed in May 2003. The average height is 5.9m and the average breast diameter is 6.4cm. The growth can be compared with the local eucalyptus forest. Forests can also be planted in hilly areas, but the elevation of forest land should be more than 200m. If planting in areas below 200m, “sunburn†will burn the stems and branches, which will affect their growth and even death. The growth of Betula platyphylla is rapid, and it is another excellent fast-growing precious tree species after eucalyptus. It is mixed with negative or neutral shade tree species, such as red needle, wood lotus, fragrant incense, eucalyptus, fir and many other coniferous and broad-leaved species. Wide, wide-broad mixed forest, not only grows well, but also has good forest structure, strong protective performance and good ecological effect. Economic Value The southwestern birch wood is not warped or cracked, has a small dry-shrinkage ratio, is not easily deformed, and has beautiful patterns and colors. It is commonly used as plywood, high-grade furniture, wood flooring and interior decoration materials in addition to traditional furniture, construction and military applications. Its resonance performance is good, and it is also an excellent instrument material. The bark contains 6.9 to 11.6% of tannin and can be extracted from tannin. The use of southwest birch wood is relatively high in economic value, and the price of wood is rising. It is 600-700 yuan/m3 in the 1980s and 1000-1400 yuan/cubic meter in the 1990s. It currently stands at more than 2,000 yuan/m3. The results of the natural forest survey show that the 30-year-old breast diameter is 35cm, the tree height is about 25m, and the accumulation is 54.12 cubic meters/mu, (811.78 cubic meters/ha), which can produce 568.25 cubic meters/ha of wood, with an output value of 75760 yuan/mu, (1136400 yuan). / hectare), the average annual output value is 56,820 yuan / hectare. Wood trait Deciduous trees. The bark is brown to reddish brown, and the paper is transversely peeled off. The wood is reddish brown to taupe, the difference between the heart and the sapwood is not obvious, the growth wheel is slightly obvious or obvious, and the wheel boundary is thin. The tube hole is slightly less, slightly smaller to medium, and evenly distributed (discrete material). Axial parenchyma was not seen. The wood ray is as low as medium; it is very fine to slightly fine, and it is clear under the magnifying glass; there are very fine ray spots on the radial section. The texture is straight, the structure is fine, uniform, and the hard weight is medium. Springs classified by material Springs Classified By Material,Brass Spring,Nickel Plated Spring,Tinned Spring Dongguan Jiufukai Hardware Products Co., Ltd , https://www.jfkspring.com
Wood Encyclopedia - Southwestern Birch