Populus euphratica is a tree species grown in arid continental climate conditions. It likes light, resists heat, resists atmospheric drought, resists salt and alkali, and resists wind and sand. It does not grow well in hot and humid climate conditions and heavy clay soils. Populus euphratica requires sandy soil. Wherever the desert rivers flow, Populus euphratica will follow. Desert rivers change quite frequently, so Populus euphratica leaves traces of its past everywhere in the desert. Populus euphratica relies on the protection of its root system, and the groundwater level is no less than 4 meters, so Populus euphratica can live very comfortably; after the groundwater level drops to 6 to 9 meters, Populus euphratica becomes languid; if the groundwater level drops any further, Populus euphratica will die. . [2]
Populus euphratica is a typical mesophytic to mesophytic plant that replaces floods and droughts in desert areas of Asia and Africa. It has long been adapted to the extremely arid continental climate; it has strong adaptability to large changes in temperature, and it likes light. It likes moist soil and is resistant to atmospheric drought, high temperature, and cold. It is suitable for warm temperate desert climates with accumulated temperatures above 10℃ and between 2000 and 4500℃. —Grows best on sandy soil. It can withstand the extreme maximum temperature of 45℃ and the extreme minimum temperature of -40℃. Populus euphratica has strong salt-alkali tolerance. When the total soil salt content within 1 meter is less than 1%, it grows well; when the total salt content is 2 to 3%, the growth is inhibited; when the total salt content exceeds 3%, it becomes piece of death. [1]
Popular euphratica (73 photos)
Popular euphratica has a strong adaptability to large changes in temperature. The water for its growth mainly depends on diving or river flood water, so it has a root system that extends to near the shallow water layer, strong root pressure and leaves containing sodium bicarbonate, so it can resist drought and salt. Populus euphratica is the only tree species living in the desert. It has witnessed the process of desertification in the arid areas of northwest China from beginning to end. Although it has retreated to the desert riparian zone, it is still the living soul of the desert known as the "Sea of ??Death." As long as you see rows of fresh or dried Populus euphratica in the desert, you can tell that water once flowed there. Because of this, some people call Populus euphratica an "irresponsible mother". It leaves its descendants everywhere without caring about their life or death. In fact, this is a kind of helplessness against environmental constraints. [1]
Main value
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Ecological value
Populax euphratica
Populaver euphratica is endemic to desert areas precious forest resources. Often growing in deserts, it is cold-resistant, drought-resistant, salt-alkali-resistant, wind-sand-resistant, and has strong vitality. Populus euphratica forest is a precious forest resource unique to desert areas. Its primary function is to prevent wind and sand, create a suitable oasis climate and form fertile soil. For thousands of years, Populus euphratica has resolutely guarded the border desert and watched the wind and sand. Populus euphratica is also known as the "Guardian of the Desert". Populus euphratica plays a very important role in stabilizing the ecological balance of desert river areas, preventing wind and sand fixation, regulating the oasis climate and forming fertile forest soil. It is a natural barrier for the development of agriculture and animal husbandry in desert areas.
Populus euphratica is an older tree species and has important scientific value for studying climate change, river changes, flora evolution in desert areas of Asia and Africa, and the development of ancient economy and culture. [1] The role of Populus euphratica forest in improving desert ecology. A considerable part of Xinjiang, Inner Mongolia and western Gansu is occupied by Gobi and deserts, which are dry and rainless. The desert climate in the Tarim Basin in southern Xinjiang is particularly strong. Populus euphratica is mainly distributed around the Taklimakan Desert, like a green Great Wall, tightly locking the expansion of mobile sand dunes.
Xinjiang’s agricultural areas are mainly distributed in patches and strips of oases on the edge of the desert in the northern and southern Xinjiang basins. Most of them are surrounded by the Gobi Desert and are under the threat of drought and sandstorms. Inner Mongolia and western Gansu, Also in a similar natural environment. Such harsh natural conditions cannot ignore the Populus euphratica forests distributed on both sides of rivers and flood-eroded lands in these areas. Due to the existence of these Populus euphratica forests, the drought and harsh climate can be alleviated. In the Tarim River in southern Xinjiang, natural Populus euphratica forests are distributed on both sides of the upper reaches and in the vast areas downstream, forming a continuous natural forest belt hundreds of kilometers long. This natural forest belt plays a positive role in preventing wind and sand fixing, regulating the climate, effectively blocking and slowing down the northward movement of the southern Taklimakan Desert, and ensuring oasis agricultural production and stable life of residents. Since a large number of Populus euphratica forests grow on both sides of the river, it protects It strengthens the river bank, reduces soil erosion and loss, and stabilizes the river bed. The shade coverage of Populus euphratica forest, on the one hand, enhances the biological drainage effect on the soil, on the other hand, it relatively slows down the direct evaporation of water in the upper layer of the soil, inhibits the process of soil salinization, and thus improves the soil to a certain extent. role. The huge role that Populus euphratica plays as a desert forest in the vast desert of northwest China is difficult to estimate using general figures. [1]
Medical effects
Resin: clearing away heat and detoxifying, producing antacid and relieving pain. It is used for sore throat, toothache, lymph node tuberculosis, gastric and duodenal ulcers, stomach pain, and hyperacidity; for external use to treat otitis media and hemorrhoids.
Root: repels insects.
Inflorescence: Hemostasis. External use to stop bleeding.
Usage and dosage: Caloridine (resin, crude product): 2 to 3 qian, decoction in water; appropriate amount for external use. Root: 3 to 5 qian, decoction in water and taken.
Economic Value
Populus euphratica is used for horticulture and ornamental purposes. It is evergreen and has a beautiful tree shape. It is an excellent street tree and garden tree species.
Timber is used for construction, bridges, farm tools, furniture, etc. The wood fiber is 0.5-2.2 mm long, with an average length of 1.14 mm. It is also a good raw material for papermaking; it is an excellent tree species for greening the arid saline-alkali zone in northwest China. [2]
Popular euphratica is a treasure all over: its wood is hard, water-resistant and corrosion-resistant, and has lasted for thousands of years. It is a top-quality building and furniture material. The poplar euphratica building materials in ancient desert cities such as Loulan and Niya are still preserved today. In good condition; the leaves are rich in protein and salt, which is a good feed for livestock over the winter; the poplar wood has long fibers and is a good raw material for papermaking, and the dead branches are a good fuel. Populus euphratica forests and twigs are important fodder in desert areas; although wood is not ideal, it is still an important material in deserts where wood is scarce; both leaves and flowers can be used as medicine, so Populus euphratica is a treasure tree in the desert. [1] [3]
Poplar euphratica and gray poplar wood have strong corrosion resistance, especially after being soaked in water, the corrosion resistance increases. In saline-alkali areas, the wood of Populus euphratica is used as the basic material of bridges and culverts, which is durable and durable. However, under unstable conditions of dryness and humidity, the corrosion resistance drops significantly, and it will completely decay in less than 2 years. In the Tarim River Basin of southern Xinjiang, local people often use large-diameter Populus euphratica wood to make canoes, called "Kapen" in Uyghur, and they have become an important tool for fishing and crossing the river.
The fiber quality of Populus euphratica wood is better than that of other poplar trees, and it can be used as a raw material for pulp production in the paper industry. According to the measurements of Yang Tingfu and others from Xinjiang Bayi Agricultural College, the average length of Populus euphratica wood fibers is 1135.83 microns, and the absolute maximum length is 2204.52 microns. The average width of wood fibers is 23.17 microns, and the ratio of length to width reaches 68.97. The comparative data of fiber measurement between Populus euphratica and several other poplar trees show that: Populus euphratica has the largest average length of wood fiber, the smallest average fiber amplitude, the largest ratio between wood fiber length and amplitude, and Populus euphratica also ranks first in the average number and absolute maximum ratio. The ratio of wood fiber length and amplitude is related to the quality of paper. Therefore, the wood fiber of Populus euphratica has the best quality.
The leaves of Populus euphratica are a good feed for cattle and sheep, especially sheep. Green leaves, dead leaves and young branches can be used. In areas where Populus euphratica is distributed, a large number of leaves fall in the forest every year, and herdsmen often use it as a "winter nest" for sheep (that is, a winter grazing pasture). In the past, herders did not pay attention to protecting the forest when grazing, and cut down tree heads and branches, causing forest loss and damage. If proper zoning is carried out and reasonable pruning is adopted, a healthy combination of forest protection and grazing can be achieved. Populus euphratica branches and leaves can also be processed and used as fertilizer.
Popular euphratica can grow in highly saline soil. The reason is that the cells of Populus euphratica are more permeable than ordinary plants. They can absorb a lot of salt from the main root, lateral roots, trunk, bark to leaves, and It can excrete salt through the secretory glands of stems and leaves. When too much salt accumulates in the body, Populus euphratica can automatically excrete the excess salt from the knots and cracks of the trunk, forming white or light yellow massive crystals, which can be used as medicine. "Populus euphratica tears" or "Wutong tears" (named because the leaves resemble Wutong leaves), are commonly known as "Populus euphratica". "Polarine" is a very high quality alkaloid. In areas where Populus euphratica grows vigorously in southern Xinjiang and western Inner Mongolia, the yield is large and easy to harvest, making it a sideline production for Uyghur farmers in southern Xinjiang. Local residents use it to make dough and steam steamed buns, because the main component of poplarine is baking soda, and the purity of its alkali is as high as 57% to 71%. In addition to being used for food, poplarine can also be used to make soap, and can also be used as a raw material for degumming and degreasing apocynum. An adult tree can discharge tens of kilograms of salt-alkali every year. Populus euphratica can be called the "hero of soil improvement" in "removing salt and changing soil". [1]
Propagation methods
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Popular euphratica - photos of vitality (4 photos)
Popular euphratica mainly reproduces by seeds. Cuttings are difficult to survive. Populus euphratica seeds are very easy to lose water and lose their ability to germinate. In July to August, after the ears turn from green to yellow and the apex of the capsule cracks to reveal white fluff, a good mother plant should be selected in time to collect the ears and dry them out. Choose moist, fertile, well-drained fine sand soil or sandy loam soil to build a bed, ridge bed or low bed, and mix the seeds with fine sand for sowing in drills or broadcasts. The seedlings can be planted in 2 to 4 years. Either direct seeding or seedling planting can be used. [3]
Natural reproduction
Populus euphratica and poplar gray form forests in arid desert areas, and initially reproduced by seed dispersal. The maturity period of Populus euphratica seeds from July to August is the hot season and the time when rivers overflow. A large number of seeds with crested hairs are scattered by the wind on the floodplains on both sides of the river, on the shoals of stagnant lakes, at the bottom of moist dry ditches and on the slope water lines of newly constructed water conveyance channels in agricultural areas. These seeds germinate quickly, sprout and grow, and together with other companion plants, form forest communities in strips and patches.
According to a 1965 survey at Yingke and Kara lakes in the lower reaches of the Tarim River, there were 22.5 million naturally planted Populus euphratica seedlings on the shoals around these two lakes, generally along the water. The rise and fall lines are distributed and grow in the gentle slope of Haizi in a strip shape. The growth density averages 90 plants per square meter, with the densest area reaching 900 plants per square meter. The width of each seedling is about 5 to 10 meters. Due to the drop in the water level in Haizi, a distance of 10 to 50 centimeters is formed between the strips. However, in the steep slopes of Haizi, due to the rapid drop in water level and poor water retention, seeds are not easily retained, so seedlings are rare. This natural phenomenon reveals the laws of natural seeding and reproduction of Populus euphratica and Populus grisei, and provides scientific inspiration for artificial seeding, seedling raising and cultivation.
The adult tree of Populus euphratica has a strong horizontal root system, and the adventitious buds on these horizontal root systems have strong sprouting ability. When the soil moisture conditions are good and the salinity is not too heavy, a large number of seedlings can germinate, becoming the main way of natural reproduction of Populus euphratica. Under desert conditions, Populus euphratica seed propagation is limited, while root-till propagation is common. In the Tarim region of Xinjiang, wherever Populus euphratica grows, you can see Populus euphratica root tillers in borrow pits along roads, on the edges of farmland adjacent to Populus euphratica forests, and in places where licorice has been dug in the forest area. These root tillers can grow into dense secondary forests over many years. Within 20-30 meters around a Populus euphratica or gray poplar tree, the roots can reproduce dozens or even more offspring, forming a mass of young forest. These clusters of young forests constitute the special forest features of Populus euphratica and Populus gray forests in many places. [1]
Artificial seedling cultivation
It is difficult to propagate Populus euphratica cuttings. The key to sowing seedlings is to control rust damage in the seedling stage. It has been observed that Populus euphratica rust has the following period: 1-year-old seedlings have no or mild disease. Two-year-old seedlings are most susceptible to the disease. The leaves of the seedlings will turn yellow, wither, and die. Onset at the end of May. It was severe in July and August and basically stopped in early September. Seedlings are infected from bottom to top, and there is no infection or slight infection in parts with a height of more than 1.3 meters. In addition, excessive irrigation, poor drainage, and heavy rainfall in summer can promote the occurrence and spread of rust.
According to the above rules, the following main measures should be taken:
1. Pay attention to the selection of nursery land. Populus euphratica seedlings should be cultivated in a place that is ventilated and conducive to irrigation and drainage. The soil should be fertile and loose sandy loam or lightly saline-alkali land.
2. Irrigate properly and loosen soil and remove leaves in time. Irrigation of 2-year-old seedlings should be controlled and watered twice a year to meet physiological needs. Loosen and weed 4 times, especially after irrigation or rain. Topdress 1 to 2 times and thin seedlings 2 times to maintain a reasonable density. Appropriately knock off some leaves at the lower part of the seedling. It is conducive to light transmission and ventilation, lowers the surface temperature, and does not give rust bacteria a chance to move.
3. Chemical prevention and control. Once rust occurs, 15% fentanin can be used. [3]
Plant History
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Populus euphratica is an ancient Mediterranean component. It is an ancient tree species that was remnant in the third century. It was planted more than 60 million years ago. Survive on Earth. It appeared one after another in the coastal areas of the ancient Mediterranean and became an important component of small leaf forests in mountain valleys. In the early and middle Quaternary, Populus euphratica gradually evolved into the most important establishing species in desert riparian forests. Mainly distributed in southern Xinjiang, western Qaidam Basin, Hexi Corridor and other places. The Poplar euphratica tree that grows in the Tarim Basin in China takes root as soon as its young buds appear. In an extremely hot and arid environment, it can grow to a height of more than 30 meters. When the tree begins to age, it will gradually break off the branches and trunk at the top of the tree, and finally drop to a height of three or four meters, still with lush branches and leaves, until it dies of old age and is still standing. And in Ejina Banner, people praise Populus euphratica as "a Populus euphratica that survives a thousand years of life, survives a thousand years of death, remains immortal for a thousand years if it falls, and has a history of three thousand years." The iron bones are forged for thousands of years, and the unyielding quality is praised for thousands of years.
Populus euphratica was once widely distributed in the temperate and warm temperate areas of western China. Fossils of Populus euphratica have been found in Kuqa Thousand Buddha Cave in Xinjiang, Blacksmith Valley in Dunhuang, Gansu, and Pinglong in Shanxi, proving that it is of Tertiary age. Relict plants have a history of more than 65 million years. Today, except for a small amount of Populus euphratica that can be seen on both sides of some rivers flowing into the desert in the Qaidam Basin, the Hexi Corridor, and Alxa in Inner Mongolia, more than 90% of China's Populus euphratica forest area is huddled in Xinjiang, and 90% of it is concentrated in southern Xinjiang. The Tarim Basin - a region known as the "extremely arid desert".
Fossils of Populus euphratica were found in the middle of the Paleocene strata of the Tertiary Period in Kuqa Thousand Buddha Cave and Dunhuang Tiejianggou, which are at least 65 million years old. Both "Book of the Later Han·Biography of the Western Regions" and "Shui Jing Zhu" record that there are Hutong (Wutong), also known as Populus euphratica, in the Tarim Basin. In Uyghur, Populus euphratica is called Tokrak, which means "the most beautiful tree". Because Populus euphratica has amazing abilities to resist drought, wind and sand, and tolerate salt and alkali, it can survive and multiply tenaciously in the desert, so it is praised as the "Desert Hero Tree". [4]
During the Western Han Dynasty, the coverage rate of Populus euphratica in Loulan was at least 40%, and people relied on Populus euphratica for food, housing, and transportation. In the Qing Dynasty, "Hutong (i.e. Populus euphratica) was still everywhere in the fields, forming deep forests."
However, in just 20 years from the mid-1950s to the mid-1970s, the area of ??Populus euphratica forest in the Tarim Basin dropped sharply from 520,000 hectares to 350,000 hectares, a decrease of nearly one-third; in the Tarim River Downstream, Populus euphratica forest has dropped by 70%. Decline forests account for a significant portion of the surviving forests. The main reason for this outcome is human beings' irrational social and economic activities. The demise of Populus euphratica and its understory plants has caused the middle and lower reaches of the Tarim River to become one of the two major source areas of sandstorms in Xinjiang. [1]
Population status
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Most of the world’s Populus euphratica grows in China, and more than 90% of China’s Populus euphratica grows in Xinjiang In the Tarim River Basin, the Populus euphratica protected area in the Tarim Basin alone covers an area of ??3,800 square kilometers. The Populus euphratica forest in the river basin accounts for three-quarters of the total area of ??the original Populus euphratica forest in China. It was rated as the "Hometown of Populus euphratica in Tarim, China" by the China Specialty Products Hometown Recommendation and Promotion Committee.
In 2008, the 1.9879 million acres of densely populated Populus euphratica forest in southern Shaya was awarded the title of "the largest area of ??original ecological Populus euphratica forest" by Shanghai Guinness. Populus euphratica forest is also an excellent four-season pasture and a habitat for wild animals. Due to the decrease in water flow in the lower reaches of the Tarim River, hundreds of miles of Populus euphratica forest collapsed due to thirst. Although Populus euphratica has a strong vitality, it cannot escape the disaster of long-term waterlessness. This thousand-year-old Populus euphratica will not live for 100 years and will shed tears in the sea of ??sand. [4]
On April 5, 2006, the Populus euphratica growing area in Tarim, Xinjiang was approved by the State Council to be listed as a national nature reserve. Improper logging and deforestation for land reclamation or grazing have resulted in the destruction of Populus euphratica forest resources and the consequences of aggravated desertification due to land wind erosion or sand accumulation. People have learned lessons from the setback and started actions to save the Tarim River and Populus euphratica forest. The emergency water transfer to the lower reaches of the Tarim River has achieved initial results, and the Populus euphratica forests on both sides have begun the process of recovery. The Tarim Populus euphratica Forest Reserve, covering an area of ??nearly 390,000 hectares, has been upgraded to a national nature reserve. [5]
Luntai Populus euphratica Park was upgraded to a national forest park; the middle reaches of the Tarim River wetland, which is dominated by Populus euphratica woodland, has attracted the attention of international organizations and has been listed as a key protection object. A Populus euphratica forest nature reserve in desert arid areas has been established in Yuli County, Xinjiang. The Populus euphratica forest area in Ejina is one of only three remaining places in the world and is the most completely protected. Populus euphratica, which is hundreds of years old, is still flourishing and dominates the desert and sea. It is a miracle of nature. [1]
Protection measures
Reasonably adjust the relationship between agriculture, animal husbandry, and forestry in arid desert areas, and strictly prohibit indiscriminate logging; the upper reaches of each river's interception reservoirs should regularly Water is released downstream to ensure the recovery and development of Populus euphratica forests. Two Populus euphratica nature reserves should be established in northwest China as bases for scientific research and species protection. [1]
Protection methods
In 2012, the Ejina Banner Forestry Bureau installed insect warning lights in the Qidaoqiao Populus euphratica forest area to further strengthen the pest forecasting and reporting work in the Populus euphratica forest, improve monitoring and early warning capabilities and level of science and technology to enhance the timeliness of prevention and control. Proposed: "Use insect warning lights to protect Populus euphratica forest."
The insect status forecasting lamp can automatically open and close according to the changes in day and night without supervision, complete system operations such as insect trapping, insecticide, collection, packaging, and drainage, and can forecast the insect status according to the situation. In order to meet the needs of visualization, networking and standardization, the environmental meteorological data automatically measured by the system can be input into the computer at any time to monitor, analyze and predict the occurrence and development of insects to meet the needs of insect forecasting and specimen collection. [3]
Damage conditions
The water transport volume of the source and main stream of the Tarim River shows an obvious decreasing trend. Populus euphratica forests died in large areas. In the 1950s, the area of ??Populus euphratica forest in the middle and lower reaches of the Tahe River reached 5.8 million acres. In the 1970s, it was 2.97 million acres. By the 1990s, only 1.5225 million acres remained. In the past 40 years, it has decreased by nearly 3/4 at a rate of half every 20 years.
After the 1960s, 30 reservoirs of more than one million cubic meters were built in the Tarim River Basin. The entire Heihe River was basically sucked dry, causing the lower reaches to stop flowing. In addition, the precipitation was low, and in the least years there were only More than ten millimeters, but the evaporation amount was as high as 4000mm. The Juyan Sea dried up, and 850,000 acres of natural vegetation such as Populus euphratica, tamarisk, and seabuckthorn declined and died. However, it is still decreasing at a rate of 50,000 to 70,000 plants every year, and 50 million acres of grassland Due to desertification, groups of farmers and herdsmen have to move their families and become ecological refugees. [1]
The reduction in the area of ??Populus euphratica forest has also led to the continuous reduction of the types of wild animals that inhabit the forest area. In the 1970s, there were still a small number of red deer and other wild animals in the Populus euphratica forest area, but now they are basically extinct. The downstream green corridor is on the verge of destruction. From the 1960s to the early 1980s, desertification in the middle reaches of the Tahe River has been expanding. The downstream is the most severely desertified area. In the 20 years from 1958 to 1978, the proportion of desertified land in this area increased from 12% to 52%. New sand dunes continue to form, and the green corridor is in danger of disappearing.