I believe that students who have studied biology know that there is a thing called biological invasion, which means that an animal and plant that has never appeared before is introduced to the local area. Because these animals and plants have no natural enemies in the local area, they can multiply rapidly, which has finally affected the ecological balance in these areas. This phenomenon is called ecological invasion. Actually, there are many cases of ecological invasion in the world, especially in China. In order to expand production, we actually introduced many foreign varieties, such as potatoes and peppers. What we saw was actually imported from abroad, but in the end it all became our dishes. Moreover, crayfish seems to be imported from abroad, but now it is most often mentioned on the dinner table by others.

Biological invasion actually does great damage to the local environment, because they can consume a lot of nutritional resources to expand their sovereignty, resulting in no room for other animals and plants to survive. Japanese Polygonum cuspidatum invaded Britain for many years, and their problems have not been solved so far. I think this question asks how the Japanese giant knotweed invaded the United States. In fact, Japanese Polygonum cuspidatum did not spread to the United States, but expanded its own ethnic group in Britain. The vitality of Polygonum cuspidatum can be said to be super tenacious, even on the concrete floor. It can also take root and sprout, even extending to more than three meters underground. First spread in Britain, on many roads. Polygonum cuspidatum can be seen on bridges and even houses. In order to solve the hidden trouble caused by Polygonum cuspidatum, the British side spends 654.38+0.5 billion pounds every year. And even if you spend so much money, it can't be cured. Japanese giant knotweed can still do evil in Britain, and the British side has not come up with a good solution. However, Japanese Polygonum cuspidatum is not completely useless, at least it can be used as Chinese herbal medicine, but in Britain, it is known that it is impossible to be used as a medicinal material without Chinese medicine anyway.