Workers are injecting flower bud inhibitors into willow trees to achieve the purpose of inhibiting fly Catkins by using this method. He Yong photo
Millions of Poplar Willows a female plant fly catkins have troubled citizens’ lives, and Beijing and other underground efforts are expected to achieve early results.
4. May is full of spring, but it is also the season of flying all over the sky. These Catkins and catkins are not big, but the number is quite large, which brings a lot of troubles to the citizens. “I have allergic rhinitis, and I can suffer every season when catkins are all over the sky.” “I accidentally choked my nose or lost my eyes by these BIAOXIU, which is very uncomfortable.” “I wanted to go out for a outing, but seeing Yang Catkins flying all over the sky, I retreated.” How did these “spring snow” come into being? Why is there a disaster “? What is a good way to govern? The reporter interviewed relevant experts.
What exactly is Yang catkin?
Flying catkin is composed of a female plant seeds and derivatives of Willow, which is easy to assist fire in spring”
What is the scattered Yang Catkins?
Jiang Sanai, director of the forest management office of the afforestation department of the State Forestry Administration, said that poplar and willow both belong to Salicaceae and are dioecious, while the so-called flying batting is actually the seeds and derivatives of female trees. After the female flower of Willow develops, it grows into a small capsule with white flocculent fluff inside, and some sesame seeds are hidden in the middle. With the continuous maturity, the small capsule gradually splits, and those white flocculent hairs are portable with seeds flying all over the sky, using wind as the medium, spreading and multiplying the next generation.
The phenomenon of flying catkins mainly occurs in more than ten provinces and cities in the north, such as Beijing. The annual “batting army” is divided into two groups. Generally speaking, Beijing welcomed Yang Xu around the middle of April, while Liu Xu came later, from the end of April to the beginning of May. The catkins will last for about two weeks each, and the cycle will stop automatically once it passes. Jiang Sanai believes that flying catkins itself does not pose a problem, but concentration and excess will cause disaster. If the concentration of Yang Catkins in the air is too high, it will affect people’s daily life.
The harm of Yang Catkins is mainly reflected in three aspects.
First, it is not conducive to human health. If flying catkins enter eyes and nasal cavity, it is easy to cause discomfort or inflammation. Especially for people who are susceptible to allergy, exposure to a large amount of floc will stimulate and aggravate respiratory diseases such as asthma and chronic bronchitis.
Second, it will affect traffic and public safety. Floccus will block the car water tank cooling fin, resulting in flameout, and will also block the sight of pedestrians and vehicles, affecting traffic safety. Its characteristic of “seeing the fire” also brings hidden dangers to public security. “The batting cycle is basically the same as the drought period in spring in the northern region. If the cleaning is not timely, once exposed to open fire, it will assist the fire.” Jiang Sanai said. Recently, there have been several fires in Beijing caused by the rapid burning of accumulated willow catkins.
Third, flying batting will also interfere with normal industrial production and scientific research activities, posing a certain threat to the operation of equipment and affecting the measurement accuracy of precision instruments.
What is “flying catkins disaster” like?
Poplar and willow planted rapidly in that year entered the mature period.
Since Willow trees have the problem of flying catkins, why did they plant so much in those days?
According to Liu Xiuchen, the counselor of the State Council and deputy director of Beijing Municipal Bureau of garden and forestry, the existing willow trees in Beijing were mainly planted in the 1960 s and 1970 s. At that time, China’s urban greening was still in its infancy with limited investment, there are fewer tree species to choose from. At that time, poplar and willow became the main tree species for greening due to their advantages such as being suitable for Beijing’s water and soil, being easy to live, growing fast and having lower maintenance costs.
“People did not expect that in a few decades, these meritorious officials who increase the green capacity of the city will become the main characters of flying catkins.” Jiang Sanai said that due to biological characteristics and technical limitations, the period of Willow seedlings could not be distinguished between male and female, which buried hidden dangers for the later Flood of catkins.
Some citizens reported that in fact, there were not many flying batters in the early years, which only gradually became serious in recent years, and it was almost overwhelming during the close gathering. What’s going on? Jiang Sanai explained that it took some time for the willow tree to grow from sapling to mature. In the past few years, they were still “young” and would not blossom and bear fruit. There was no problem of flying batting. In recent years, it happened to catch up with the batch of poplar and willow planted in that year “. The female trees entering the mature period blossom and bear fruit, with a large amount of floc, which becomes a “disaster”.
To make matters worse, biodiversity was not considered when making Greening plans in those years, and most of the plants were “pure forests”, that is, the forests of a single tree species. Looking at the total amount, there are 2 million willow trees a female plant in the built-up area of Beijing, accounting for 5.4% of the total 37 million trees in landscaping, which is not too much. However, these willow trees are concentrated in roadside, along the river and around the village, however, the lack of other tree species in these areas has resulted in the scene of “floating snow in April. In addition, the appearance of Beijing city has been changing in recent years, with more high-rise buildings, affecting the spread of floccus. Sometimes, the building and the building will form a tiny climate like the mountains, resulting in the flying catkins spinning with the small cyclone, but they will not be scattered.
According to the introduction of the landscaping department, this spring is about 7-10 days earlier than previous years, and the time of Willow flying catkins is also 1-2 weeks earlier than previous years, so the public feels particularly obvious.
Why is Yang Liu Xu treated repeatedly?
There is no perfect governance plan at this stage, and there are many problems in actual implementation.
Flying batting has brought a series of troubles to citizens’ lives. Departments such as forestry, landscaping, sanitation and so on are also very anxious, and they have almost tried their best to control flying batting. Unfortunately, there are many methods, but each has its own problems.
One is the update method “. That is to say, a female plant of willows are eliminated, male willows or other native tree species are planted, and the existing tree species structure is reformed. This is the most direct and effective method to control Willow flying catkins. However, at present, the number of Willow a female plant in Beijing is very large. Replacing tree species requires not only a large amount of manpower, material resources and financial resources, but also a useful quantity cutting quota, which makes it difficult to popularize this method in large areas.
In addition, Shen Guozhen, an academician of the Chinese Academy of Engineering, stressed that the ecological function of willow trees is far greater than that of flying catkins and cannot be cut off. At present, there are a large number of willow species in Beijing, and most of them have formed big trees, which have the functions of releasing oxygen and fixing carbon, cooling and humidifying, reducing bacteria and sterilization, etc. If a large amount of removal, it will not only cause the decline of urban environmental quality and landscape, but also cause more serious ecological losses.
The second is “drug therapy”. That is to say, “Hang infusion bottle” to the trunk and inject flower bud inhibitor to inhibit flower bud differentiation and floc formation. However, this method cannot be implemented once and for all. It needs to be repeated every year, with high cost and long-term use, trees are prone to “rot”. In addition to “inhibition”, it can also be “sparse” with drugs, that is, spraying biological agents to promote the early shedding of Poplar female flowers and control the production of fly Catkins. However, this method has strict requirements on application time and technology, and has not been widely used.
The third is “grafting method”. Cut off the Willow a female plant crown, and graft the male scion at a high level to make a female plant “denatured” to avoid the production of fly Catkins. However, the technical requirements of this method are relatively high, and the maintenance cost after grafting is high, so the test is only carried out in a small range.
“Generally speaking, although there are many therapies for managing batting, the curative effect is not perfect.” Jiang Sanai believes that in order to achieve obvious results in a short period of time, it is difficult. It is necessary to take more measures and gradually manage them.
Can the batting be cured?
The fundamental way is to optimize the ecosystem. Beijing is confident that it will achieve “no disaster” in 2020″
In fact, Yang catkin is not a “difficult disease” and can be cured. Experts pointed out that maintaining the diversity of ecosystem and tree species allocation is the most fundamental way to solve the problem of poplar catkins. As early as the beginning of 2015, the National Greening Committee and the State Forestry Administration issued a document notice to make special arrangements to cure the problem of Yang Catkins.
“Flying catkins can definitely be cured! But this is a long-term work, which should be combined with curing symptoms and root causes.” Jiang Sanai said that if you want to solve the root cause, you must first change the idea of urban greening and no longer blindly seek fast. He stressed that the governance of Yang catkin was correcting the previous mistakes, and it was also an opportunity to re-plan and build a healthy and stable urban forest ecosystem.
Specifically, aiming at the flood of flying batting, we need to reduce the stock and control the increment. On the one hand, the proportion of fast-growing tree species such as Willow should be gradually reduced, the proportion of suitable native long service life tree species should be increased, and the existing stand structure should be adjusted. On the other hand, in the newly-built urban green space, afforestation tree species and greening modes should be scientifically configured, mixed forests should be created, biodiversity should be enriched, and ecological disasters caused by a single tree species should be avoided from the source. Secondly, the construction of peripheral green belts in urban areas should be strengthened. Since some Yang catkins flew into the urban area from the suburbs of Beijing, the construction of buffer shelterbelt can control the concentration of Catkins no longer increase. In addition, it is possible to breed excellent new varieties of willow which are fast-growing and have no fly catkins and are suitable for urban greening through technical means such as genetic improvement. Finally, there is an emergency plan, which can transform the green space composed of willow trees, plant shrubs and herbs on the ground to absorb fly catkins, and wash them with high-pressure water cannons during flowering, manual measures such as pruning shear.
How long will it take to manage the flying batting? Jiang Sanai believes that as long as we go all out and spend about 5 years, we can reduce the flying batting in Beijing by half; After another 5-10 years, we can fully control Yang catkin. “I hope the public can understand the long-term nature of this project and actively participate in it. If you want to do this well, you can not only rely on a few professionals, but also need the government’s financial and policy support, and need the assistance of a large number of volunteers. Relevant departments should also make information public to avoid inconvenience and misunderstanding to the public.”
Beijing municipal bureau of landscape and Greening said that this year, Beijing will adopt methods such as renewing tree species, thinning, pruning and chemical flower suppression in key areas to comprehensively control 400000 Willows a female plant. By 2020, the city’s Willow flying catkins will be significantly improved to achieve “no disaster if there is Catkins”. “The so-called non-disaster is not that you can’t see any flying catkins, but through reasonable control, let Yang Catkins not affect the normal life of citizens and not cause troubles to sensitive people.” Du Jianjun, deputy director of science and technology department of Beijing Municipal Bureau of Landscape and greening, explained.
There is a doorway for the protection and cleaning of batting.
Experts suggest that in the face of young Catkins flying in spring, sensitive people such as the elderly, children, and rhinitis patients should be protected. They can wear masks, use normal saline nasal cleansing, and reduce the number of trips.
The following principles should be paid attention to when cleaning up the batting: clean up in time to avoid secondary batting caused by accumulation; Clean up scientifically and adopt high pressure shower and other cooperative measures, so as not to burn it for the sake of trouble; Manage the fire source, in particular, do not ignite the flying catkins for fun. Schools and parents should strengthen the education of fire prevention awareness for primary and secondary school students.
Zhao bei jiahe yong
http://paper.people.com.cn/rmrb/html/2017-05/13/nw.D110000renmrb_20170513_1-10.htm
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workers are injecting flower bud inhibitors into willow trees to achieve the purpose of inhibiting fly catkins by using this method. He Yong’s photo of millions of Poplar Willows a female plant fly Catkins has brought troubles to citizens’ lives. Beijing and other underground power management expect early results. April and May are full of spring,