Final answer:
Kudzu, a Japanese vine introduced in the southeastern United States to manage soil erosion, has become an invasive noxious weed, overpowering native species.
Step-by-step explanation:
The organism listed as a Federal Noxious Weed due to its significant negative impacts on ecosystems of the southeastern United States is kudzu. Kudzu is a Japanese vine that was introduced to the United States in the 1870s to help control soil erosion. However, it has become an invasive species because it has no natural predators in the region, allowing it to out-compete native species and dominate various ecosystems.