What are the causes, processes and consequences of the "Rosa roxburghii" incident in Australia?

1840, an Argentine doctor from South America immigrated to Queensland, Australia, bringing an ordinary "Rosa roxburghii" bonsai-the ancestor of the Australian cactus. Rosa roxburghii is green in color, easy to grow, and will produce beautiful flowers, which are loved by everyone. After seeing a doctor, the patient picked a leaf and went home. A few days later, he took root and sprouted new plants. Rosa roxburghii is a "dwarf" in the pot, but it can grow to one person's height when inserted in the wild. Some people just put it in the yard or in the wild and let it breed freely. So Rosa roxburghii "like a duck to water", jumped out of the fence without hesitation and "rushed" to the vast grassland. 1925 In the 85th year of "legal entry", Rosa roxburghii has become the new overlord in eastern Australia-the new "immigrants" have become the dominant plants in grasslands and desert areas, occupying 240,000 square kilometers of land in Queensland and New South Wales. Wheat, corn and pasture have all become "losers" of Rosa roxburghii-cultivated land and pasture have been swallowed up by whales. Farmland is reduced, cattle and sheep have no grass to eat, and farmers and herdsmen have to abandon their land and flee.