the general name of Ulmaceae. There are about 4 species in the world, mainly in the north temperate zone, from south America to Mexico and south Asia to Himalaya. There are 24 species in China.
mostly deciduous trees, sparse shrubs and evergreen trees. Many simple leaves, alternate, with pinnate veins, compound serrations and sparse single serrations. The flower buds are spherical, and most of them bloom in spring. Individual tree species bloom in winter (such as Ulmus pumila U. lanceaefolia) or autumn (such as Ulmus pumila U. Parvifolia). Flowers bisexual, clustered or in short racemes; Fruit ripens within 1 month after flower withering; Samara is flat, with thin wings around the stone and a gap at the top. Wind broadcast.
it has been distributed all over China in China several times, such as Ulmus pumila, Ulmus pumila, Ulmus U．davidiana, Ulmus U．macrocarpa, Ulmus lamellosa, Ulmus lamellosa, Ulmus U．laciniata and Ulmus pumila in the north. In the south, there are Ulmus pumila (U. Taiwan Province), Ulmus pumila (U. Castaneifolia), Ulmus pumila (U. Elong ATA) and Ulmus pumila (U. Changii). There are U．kunmingensis and U．microcarpa in the southwest. Among Ulmus plants, Ulmus pumila is the most important in afforestation.
Ulmus pumila is a deciduous tree, with a height of 25m and a DBH of 1m. Its leaves are elliptic, ovate or elliptic-lanceolate, 2-8cm long, with irregular compound serrations and single serrations, hairless or tufted hairs in the axils below the leaves, and its petiole is 2-6mm long. Flowers clustered; Fruit suborbicular or obovoid. Mainly distributed in Northeast China, Northwest China, North China and East China; Most of them are born on both sides of rivers, foothills and fields below 1 meters above sea level; It can reach 15 meters above sea level in Tianshan Mountain in Xinjiang and 24 meters in Qinling Mountain in Shaanxi Province. Hi light. It has strong adaptability to climate, can grow in cold temperate zone, temperate zone and subtropical zone, and can withstand the absolute low temperature of -4℃ in winter. It can also adapt to the warm, hot and humid climate in the south; It can grow normally in the northwest sandy area where the annual precipitation is less than 2mm, the air relative humidity is less than 5%, and the absolute maximum temperature in summer reaches 45℃. The requirements for soil are not strict, but sandy loam and light loam, which are deep, fertile, moist and well drained, grow best. Deep roots. Grow rapidly. Strong resistance to urban pollution, especially to hydrogen fluoride and smoke. After samara matures, it is easy to reduce the germination rate under natural conditions. If sealed and stored at low temperature (below 5℃), the germination rate can be maintained for 1 ~ 2 years. During afforestation, seedlings can be raised by seeds, the sowing amount per mu is 2 ~ 3 kg, the soil is covered by .5 ~ 1 cm, and seedlings emerge in about 7 ~ 1 days. Nursery should always be moist, and weed, loosen soil and fertilize in time to promote seedling growth. Generally, 2 ~ 3-year-old seedlings are planted, and the plant spacing is 2×2 or 2×3 meters. For afforestation in saline-alkali land, in the first year of light saline-alkali land, it is necessary to dig holes in winter, enclose water, wash alkali to desalt and plant in autumn; In heavy saline-alkali land, deep ditches can be dug or terraced fields can be narrowed, and salt can be washed by irrigation or fresh water can be stored to suppress alkali, so that the soil salt content can be reduced below .3%, and then big holes can be dug for planting. There are many kinds of elm pests, such as elm leaf beetle, Elaeagnus angustifolia, big bag moth, etc., and wood moth and so on. Dutch disease of Ulmus pumila is a serious disease in the world, but it has not been found in China. White elm is straight in wood grain, thick in structure, beautiful in pattern, slightly hard and heavy, tough, good in bending performance, resistant to wear and corrosion, and is an excellent material for building, shipbuilding, interior decoration, floor and furniture. Bark fiber is tough and can be used as artificial cotton and papermaking raw materials. Leaves contain starch and protein and can be used as feed. Peels, leaves and fruits are used as medicine, and seeds can be used to extract oil, which is a raw material for medicine and chemical industry.
elm, known as "elm knot in one's heart", is said to be difficult to cut if it is not enlightened. In fact, from the present point of view, the old elm is more like a veteran of the "market" who understands amorous feelings. No matter in front of the Wangxie Hall or in the backyard of the people, it can be seen as its standing figure, bold and hearty laughter and decorative talent. The old elm, which is rewarded for elegance and vulgarity, occupies a huge share of the market with its tough character, heavy personality and open mind, and has won unanimous praise and appreciation!
Ulmus pumila, Ulmus pumila, mainly producing temperate zone, deciduous trees, tall trees, all over the north, especially in the Yellow River basin, can be seen everywhere. Ulmus pumila has tough wood, clear texture, moderate hardness and strength, which can be adapted to general through-carving relief, smooth plane, beautiful chord pattern, and "chicken-winged wood" pattern, which can be used for furniture, decoration and so on. Ulmus pumila can be dried, shaped, carved, ground and painted to make exquisite carved lacquer crafts. It can be seen everywhere in the furniture market in the north.
elm and beech produced in the south are called "beech in the north". And the width of the material is large, and the texture is warm and excellent; The deformation rate is small, and the carving patterns are mostly rough. It's a great man in the wood, a gentleman.
Ulmus pumila can be divided into yellow elm and purple elm. Ulmus pumila is more common, and the wood is yellowish when it is newly cut, and the color gradually deepens with age; The purple elm is naturally black and purple, and the color of the heavy elm is similar to that of the old mahogany. Therefore, the largest furniture in the north is elm, which is made by waxing and painting. Elm is made of other materials, and traces of elm furniture can be seen at any time in Shanxi, Shandong, Hebei, Henan and other ancient furniture provinces. The production of elm furniture spanned a long time, and it never stopped production from the early Ming Dynasty to the late Qing Dynasty, and its evolution process and regional characteristics were very clear. Early elm furniture was mainly dedicated to furniture, such as offering tables and cases, shaped like Gu Zhuo, and mostly displayed in temples, family shrines and other places, so it can be preserved to this day. There is a wooden basin made of elm wood carving, which has no paint or decoration. After long-term touching and air oxidation, the patina is bright and dazzling, and the wood grain is old and vigorous. A hundred-year-old relic, intact, caresses the heart like crisp. As if touching the face of the vicissitudes of life.
There is a saying in the market that white wood can also be collected, which refers to Yu wood in the Ming Dynasty and Nan wood in the Qing Dynasty. However, because of the beautiful natural grain of elm, tough texture, straight and straightforward texture, and the unique simple and natural color and charm of elm, all of them are in line with the concept of being a man respected by the ancients. Therefore, from ancient times to the present, elm is very popular, and it is the first choice for making furniture from dignitaries, literati and down to the people of Li.
as far as its history is concerned, since the era of furniture, there has been elm furniture. Elm furniture represents not only a tradition, but also a culture, a taste and a style. Therefore, elm furniture is gradually collected and enjoyed by more and more people. Therefore, when collecting elm furniture, we must start from the craft, the carver should be delicate and the lines should be smooth; It depends on whether the appearance is complete and beautiful, but also on whether the workmanship is fine and perfect. For example, the production of table utensils is generally fine, and its value is even higher than that of a large piece of furniture. Collectors see whether it can preserve its value, mainly because of the following considerations. First, the beauty of the form and the shape of the furniture, no matter how complicated or simple, depend on whether it is attractive or not. Second, the material is excellent, and the log material can be preserved for a long time, so that the more you use it, the more moist it becomes. Third, exquisite workmanship, elegance and generosity, comeliness and elegance, and good aesthetic intention. Of course, it is also valuable to get a batch of classical elm furniture with good carving and complete appearance. Even so, if you can have one or two pieces of elm furniture, it will be enough to decorate the room and shine.
ecological habits
light-loving, cold-resistant, drought-resistant, water-resistant and wet-resistant. Can adapt to dry and cool climate; Like fertile, moist and well-drained soil, it can also grow in arid, barren and light saline-alkali soil, and it grows rapidly. In 3 years, the height of the tree is 17m and the DBH is 42cm. The service life can be as long as more than 1 years. Strong germination, pruning resistance, deep taproot, developed lateral root, strong wind resistance and soil conservation. Strong resistance to toxic gases such as smoke and hydrogen fluoride.
propagation and cultivation
sowing is the main method of propagation, and tillering is also acceptable. Elm seeds are easy to lose germination ability, so they should be sown immediately after harvesting. In Beijing, seeds are usually collected in late April when samara turns from green to yellow and white and a few of them fly. There is no need to do anything before broadcasting. The row spacing of bed sowing or field sowing is about 2cm, and the covering soil is .5 ~ 1 cm. The sowing amount is 5 ~ 7 kg per mu. In seedling management, attention should be paid to pruning the lateral branches frequently to promote the upward growth of the trunk and keep the trunk straight. One-year-old seedlings are about 1m high, and the highest height can reach 1.5 ~ 2 m. As urban greening seedlings, they need to be planted separately for 2 ~ 3 years before they can leave the nursery. The common pests of elm include golden flower worm, longicorn beetle, thorn moth, elm moth, elm moth, etc., and attention should be paid to early prevention and control.
Garden use
Elm is an important tree species for urban and rural greening, with straight trunk, high tree shape, strong shade, strong adaptability and fast growth. It is suitable for planting as street trees, courtyard shade trees, shelter forests and "four sides" greening. It can also be planted alone or in groups in the garden. In dry and barren land, it is often shrub-like, and some people use it as a hedge. Because of its strong germination ability, it can be dug from the wild to make bonsai. In forestry, it is also one of the main tree species to build windbreak forest, soil and water conservation forest and saline-alkali land afforestation.