Frequent rain, Mikania

Recently, people reported that a large area of green land in Huanggang Park was wrapped and covered by Mikania, known as "plant killer" It is understood that July to September every year is the breeding season of Mikania micrantha During this period, if not cleaned up in time, it will seriously damage the forest ecology and pose a greater threat to the forest resources In the South Gate of Huanggang Park, where there are about 10000 square meters of land to be built, a large number of plants are entwined by Mikania micrantha These Mikania micrantha climb along the edge of bamboo, trees, garden crops, crops, etc., wrap up the trunk and branches, grow to the top of the tree and completely cover the crown, so that the trees can not carry out photosynthesis until the trees die Walking along the mountain path, you can see similar scenes everywhere on the grassland along the road "We've been cleaning up Mikania Recently, because of frequent rain, Mikania grows very fast, and can grow more than 10 cm a day " Park staff told reporters that the park attaches great importance to Mikania, there has been a special management team to clean up Mikania, but due to the recent rain, cleaning is not so timely "We will definitely get rid of Mikania before it blooms," he said According to reports, there have always been Mikania micrantha in Huanggang Park, which is relatively concentrated In recent years, due to regular cleaning, the situation is much better According to Dr Zhang Shouzhou of Xianhu botanical garden, because Shenzhen is located in the coastal area, with a subtropical climate and a warming climate, under this climate condition, the invasive plant Mikania micrantha may grow more vigorously this year, accelerating its spread and invasion Mikania micrantha, native to central and South America, is one of the 100 most destructive invasive organisms in the world and a perennial vine Once the plant settled down, it grew rapidly, climbing anything vertical, including crops, shrubs, trees, walls and fences Now it has invaded many countries and regions including China It has been many years since the invasion area of Mikania micrantha decreased, and it has harmed the local plants in Shenzhen What is the current situation after multiple treatments? The peak area of Mikania micrantha in the city is 160000 mu Compared with that in the same year, the area of Mikania micrantha in the city has decreased significantly and the spreading momentum has been curbed, the relevant person from the municipal Wildlife Protection and management office said According to reports, the growth records of Mikania micrantha were found in 1984 in our city It is preliminarily determined that it was spread from Hong Kong to our city After years of growth and accumulation, its harm gradually broke out in 1999 According to statistics, the area of initial investigation in 2000 was 39000 mu, which was 82000 Mu at the end of 2012, nearly half of the peak Mikania micrantha is distributed in ten districts of our city, mainly endangering the economic forest and the natural secondary forest seriously disturbed by human beings It is common around the wetland such as orchard, forest edge, gully stream reservoir, vegetable land and wasteland Since 2006, the city has adopted chemical, biological control and manual removal methods to prevent and control Mikania micrantha, with a total area of 470000 mu (including repeated control) and an investment of 63 million yuan, which has curbed the rapid spread and spread of Mikania micrantha After years of prevention and control, no Mikania micrantha can be found in key areas such as provincial roads, national roads and expressways "Mikania micrantha is commonly found in the ecological communities damaged by human activities Some places in Shenzhen have stable forest ecosystems and have not yet been invaded by Mikania micrantha, such as Sanzhoutian, paiyashan, Qiniang mountain, etc., which are the places where Mikania micrantha has been found," said a person from the municipal Wildlife Protection and management office The unscientific elimination of Mikania micrantha is still a scientific research problem in the world, and there is no quick and thorough eradication method In order to control Mikania micrantha, Shenzhen city has formulated a letter of responsibility this year, aiming to control the occurrence area of Mikania micrantha in the city below 100000 mu, and curb its spread trend "At present, we haven't found a method and drug to completely cure Mikania micrantha." The person in charge said that it is unscientific to completely eliminate Mikania micrantha, which can only be controlled to a certain extent, so that it can not be harmed The relevant person in charge of the municipal Wildlife Protection and Management Office explained that Mikania micrantha can reproduce asexually, and its branches can take root and sprout when they fall to the ground when they are exposed to water A section of Mikania micrantha accidentally dropped on the ground can often grow several new seedlings Although spraying herbicides is effective, sometimes the seeds of Mikania micrantha fall in the soil, herbicides are difficult to penetrate and play a role, and can germinate and take root in winter What's more, herbicides are toxic and can't be sprayed on rivers, fish ponds and farmland In 2012, the control area of Mikania micrantha was 6268400 mu, mainly by chemical control and manual removal, with a control rate of 89% The city and district actively carried out research and application of new technologies The city forest protection station entrusted Sun Yat sen University to continue the research on ecological control technology of Mikania micrantha, and carried out the application experiment of ziweiqing Longgang District carried out a large area of application experiment of "quweiling" In addition, Shenzhen also tried to use another Liana plant, dodder, to parasitize on Mikania micrantha and control its spread According to reports, planting dodder in the field around Mikania micrantha will tightly wrap its seedlings around the branches and stems of Mikania micrantha, penetrate into the skin of Mikania micrantha to absorb its water and nutrition, and eventually lead to Mikania micrantha's death Dodder can only parasitize on harmful weeds such as Mikania micrantha, which has no obvious effect on other trees, shrubs, vines and herbs, but can promote the growth of species diversity around However, some experts said that natural enemies have been introduced to deal with "plant killers" at home and abroad, which has set a precedent for new species invasion Therefore, this control method of Mikania micrantha needs further study.